Geology and Soils
Preston2146
chapter_16_17_18.docxMarriott, B. (1997). Environmental impact assessment: A practical guide. New York, NY: McGraw-Hill.
16.1 Describing Existing Resources
The level of detail on geology and soils required to determine the po- tential fOT impact, and thus included in Section III of the DEIS or within the EA, will greatly depend on the type of project alternatives being proposed. Projects requiring excavation or tunneling or causing changes in drainage patterns may dictate more detailed studies than those with no substantial surface disturbance.
16.1.1 Geologic features
As a basis for impact assessment, the analyst should obtain an under- standing of the basic physiography and topography of the site or area and the underlying geology. Local planning documents and discus- sions with local agencies will normally provide geologic information.
The U.S. Geological Survey (USGS) also is an excellent source of in- formation on geology, geologic hazards, groundwater quality, and sur- face water flow characteristics. The USGS is the principal source of scientific and technical expertise in the earth sciences within the fed- eral government and has been providing data and reports for more than 100 years (U.S. Department of Interior, USGS 1995£).
Information and mapping will indicate important characteristics of geologic formations, such as stability for construction, permeability and porosity, groundwater aquifers, seismicity and faults, sinkholes, springs, natural gas or oil wells, surface and deep mines, mineral re- sources, and volcanic activity. Engineering limitations and constraints may include difficulty of excavation, cut slope stability, and foundation stability. In earthquake-prone areas, regional risk assessment maps are available from the USGS. Based on collected ground-motion data and other geologic information, the hazard maps provide estimates of the probability of significant ground movement and the potential areas of landslides, mud flows, and liquefaction. Liquefaction is the temporary change of a saturated soil or fill to a liquid, which produces a corresponding loss of support strength for structures.
16.1.2 Seismicity
If applicable to the study area, existing information on faulting and seismicity should be included in the environmental document. Often information on faults will be available on a regional basis and on a very localized basis through local universities or independent experts. Previous environmental studies for other projects in the area are a valuable source of information. Normally, major faults will be readily identified, but minor faults may not be identified or may be identified only as "potential.
Detailed studies on existing faulting and seismicity characteristics would be conducted by qualified geologists or geotechnical engineers. In some cases, it may be necessary to excavate test pits or trenches to investigate fault potential. The trenches would permit determination of the age of the subsurface material and evidence of surface rupture through examination of whether underlying strata are continuous or discontinuous. Discontinuous strata could indicate fault ruptures.
Information available from a seismicity study will normally include the maximum credible earthquake (MCE) and the maximum probable earthquake (MPE) magnitudes. The MCE is the largest possible earth- quake considering the known tectonic framework of an individual fault, and the MPE is the largest earthquake likely to occur with a 100-year return period. Associated with these estimated maximum earthquake magnitudes, the peak horizontal ground acceleration is calculated. The duration of strong ground shaking for each fault also may be estimated.
The seismicity information in the environmental document should in- clude history of earthquakes in the project area or region, their magni- tudes, and the locations of epicenters. Characteristics of the earthquake activity, as related to study area faults, should be described, if known.
16.1.3 Mineral resources
The description of mineral resources should include a summary of po- tential mineral ores, natural gas, oil, geothermal resources, and sand and gravel. Mineral ownership, existing and proposed resource recov- ery activities, and the potential for resource development should be de- scribed, if relevant to the characteristics of the proposed project or action. The potential for undiscovered mineral resources has already been assessed for some geographic areas, and it depends mostly on the underlying geology. For example, an area's potential for oil and gas pools in a favorable spatial relationship is rated high if three geologic necessities exist: (1) a geologic trap, an impermeable lithologic barrier, to prevent the oil and gas from escaping to the surface; (2) suitable reservoir rock, a unit with sufficient porosity and permeability to hold a quantity of oil and gas and transmit it when penetrated by drilling; and (3) mature source rock, usually a carbon-rich shale or limestone, which could have generated hydrocarbons during burial, compaction, and heating. Most of the lands within national forests or under the ju- risdiction of the Bureau of Land Management have been mapped for low, moderate, or high potential for each ofvarious mineral resources.
Mter the potential for resource is known, nongeologic factors influ- ence whether the resources are actually feasible to develop. These economic-setting factors include the market value of petroleum and the geography of the area. Geography is important in calculating the cost of recovery, such as rugged terrain, distance from support facili- ties, and distance from markets, which may make the expected re- turns from drilling insufficient to cover extra expenses incurred.
Both the potential presence of mineral resources and economic fea- sibility enter into the determination of potential for resource develop- ment. The potential for development should be included within the environmental document if it is predetermined, mapped, and relevant to the type of proposed project or action being considered.
16.1.4 Soil surveys
Information and mapping on soils are available in soil surveys from the Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service (SCS). For each soil map unit, the soil sur- vey provides an abundant amount of information related to other areas of potential impact. Depth to groundwater, erodibility, and drainage characteristics will be important to assess the potential im- pact on water resources. Depth to bedrock, permeability, available moisture capacity, and suitability or limitations for construction use may affect engineering studies and whether local soils would need to be removed and/or replaced prior to construction. Limitations identi- fied for each soil series would include such information as high frost heave potential, possible sinkholes, flooding potential, slow perme- ability, or seasonal high-water table.
Infonnation for each soil type includes the types of soils, such as silt loam, clay, and alluvium and the percentage of slope of the land within the mapping unit. The soils survey also provides interpretations for different uses, such as cropland, forest land, rangeland, homesites, recreation, wildlife habitat, and septic tank filter fields. The survey will identify prime farmland soils, soil of statewide importance, and hydric soils. Hydric soils are soils that are saturated, flooded, or pond- ed long enough during the growing season to develop anaerobic (no- oxygen) conditions in the upper part. Infonnation on the presence of hydric soils is necessary for the identification of wetlands and is dis- cussed further in Chap. 20.
16.1.5 Contents of the environmental document
Because of the abundant information on geologic resources and soils that will be available for review, it is extremely important that the environmental analyst remain focused on relevant issues and con- cerns. The characteristics of the proposed project or action and the re- sults of agency and public scoping should direct the review of available information to that which may assist in impact evaluation. Special geologic constraints, hazards, mineral resources, and soil characteristics within the actual area of potential impact should be summarized in the environmental document. The presence of hydric or prime farmland soils should be indicated and mapped, if signifi- cant. The goal is to identify any possible serious constraints or con- flicts in compatibility of the proposed project or action with existing geologic and soil resources characteristics.
16.2 Geologic Impacts
The evaluation of geologic impacts and geology-related impacts will be specific to the type of project proposed for implementation. Often impacts are avoided through incorporation of specific design criteria within permits or contractors' specifications. Mineral resource recov- ery has direct geologic impacts. Geology-related impacts can occur, particularly to groundwater and surface water resources.
16.2.1 Geologic hazards
In the assessment of possible geology-related impacts, it is important to first attempt to avoid geologic hazards or existing resources, such as sinkholes, caves, gas wells, surface mines, or gravel quarries. Emphasis again is placed on the continuing process of refining alternatives throughout the environmental impact assessment process. Alternatives should minimize impact related to geologic hazard areas as much as possible through shifts in site locations or design characteristics.
16.2.2 Land-use compatibility
In many situations, the evaluation of geology and soi1s·related im- pacts is basically an evaluation of land-use compatibility. The charac- teristics of the proposed project or action should be overlaid upon the critical relevant geologic and soils data to determine the compatibility of the proposed use with the existing features of the geology and soils.
For many types of projects, this evaluation of land-use compatibility has already been done and is reflected in various building codes, legis- lation, regulations, and permits. For example, a certain type of landfill must not be built within 200 ft of land that has been ruptured by Holocene faults (active within the past 10,000 years). Some design cri- teria for buildings, landfills, dams, and highway structures are based on assumptions related to seismic activity. The structures must be de- signed to withstand a certain earthquake magnitude and horizontal
ground acceleration without damage to foundations or structures that control pollution and without risk to human life or property.
16.2.3 Mineral resources
Potential impacts on mineral resources and resource development will be most critical with environmental studies when the proposed project or action is a land-use or management plan, such as those for national forests or land under the jurisdiction of the Bureau of Land Management. The analyst again should be aware that various federal and state agencies have been established with specific directives on the resources under their jurisdictions. See the discussion in Chap. 5 on the conflicts that can sometimes arise because of differing mandates, in that example between the Environmental Protection Agency's re- sponsibility to protect the nation's air quality and the Department of Transportation's responsibility to provide the nation with safe and effi- cient transportation.
As an example related to mineral exploration, and development on federally owned lands, it is frequently unknown by the general public that the same act (Organic Act of 1897) that created the National Forest System also opened the national forests to mineral development. Forest Service mineral management policy was first set in 1907. Under the caption "To the Public" Gifford Pinchot, first chief of the Forest Service, gave the following directive:
The timber, water, pasture, minerals and other resources of the National Forests are for the use of the people. They may be obtained under rea- sonable conditions without delay. Legitimate improvements and busi- ness enterprises are encouraged.
Numerous directives and laws since that time have reinforced the general mineral resource management policy of the systematic discov- ery and characterization of mineral and energy resources so that the most important deposits can be developed and utilized to best meet the needs of society. Because the Forest Service does not discover or develop energy or hardrock mineral resources, the achievement of the policy is defined by the amount of access provided to industry so it may discover and develop the nation's mineral resources. The guideline against which mineral resource management is measured is that at least 75 percent of the federal mineral estate is available for reasonable and prudent ener- gy or mineral exploration (U.S. Department of Agriculture, Forest Service 1992a). The area involved, however, is small; less than 1 percent ofnational forest land has ever been disturbed by mineral development.
Protection from adverse impact to the environment by mineral re- source development is ensured through requirements for environmen- tal impact assessment of proposed activities and for reclamation of lands disturbed by mineral and energy activities for other productive uses. Mineral exploration and development is a temporary and widely scattered land use. Mineral commodities are open to development only under leases, permits, or licenses issued by the Bureau of Land Management, which has the responsibility for leasing all onshore fed- eral minerals. Environmental analysis is required for each stage of mineral development activities.
The direct impact of mineral resource development on mineral re- sources is depletion of the resource and associated benefits to the na- tion's energy and minerals supply and security. Indirect effects may be the creation ofjobs and economic benefits at the local, state, and feder- allevels. Direct effects on soils may include disturbance within highly erodible soils (refer to discussion of soil erosion later in this chapter).
Mineral resource development can produce direct and indirect, sec- ondary effects on other resources and, in this sense, is evaluated in an Environmental AssessmentlFinding of No Significant Impact or Draft and Final Environmental Impact Statements, the same as any other proposed project or action. Impacts are possible to air quality, water, wetlands, recreation, visual quality, cultural resources, vegetation and wildlife, and socioeconomics.
16.2.4 Geology-related effects
Other types of impacts associated with geologic conditions include these:
• Removal and disposal of unsuitable material
• Leaching of pollutants into groundwater systems
• Interception of the water table through excavation and resultant re- quired pumping (dewatering) during construction
• Exposure of acid-producing geologic formations to rainwater
Geologic considerations are directly related to the quantity and quality of groundwater resources. These potential groundwater and surface water impacts are discussed in greater detail in Chap. 18.
16.2.5 Interdisciplinary approach
If the proposed action is a construction project, such as a building, mall, highway, bridge, or harbor improvement, engineers will be an important part of the multidisciplinary team working on the develop- ment of project alternatives. In these cases, engineering investigations of geotechnical conditions will be conducted. These investigations will normally focus on the engineering suitability of geology and soils in the area, as opposed to natural qualities such as groundwater leaching or exposure of acid-producing formations.
There will, however, be overlap in many areas of information valu- able to both engineers and environmental impact analysts. The im- portance of continued team interaction and sharing of information cannot be overemphasized. Often those in environmental disciplines can make engineers aware of potential problems early in the design process. Moreover, engineers will be able to directly answer questions required for the environmental team members to fully understand ex- actly what will occur during construction so that the degree of poten- tial impact can be properly evaluated.
Detailed subsurface engineering studies are undertaken after the environmental impact assessment process, during final design, and before construction of the selected alternative, to ensure no major im- pact related to foundation or stability conditions.
16.3 Erosion
Although many people in the United States no longer think about it in any detail, the nation's soil is an extremely important natural re- source for food production and public welfare. As early as 1935, the Soil Conservation and Domestic Allotment Act recognized that "the wastage of soil and moisture resources on farm, grazing, and forest lands of the Nation, resulting from soil erosion, is a menace to the national welfare..." and established the Soil Conservation Service (now the Natural Resources Conservation Service) with the purpose of providing permanently for the control and prevention of soil ero- sion.
As with hydric and prime farmland soils, the Natural Resources Conservation Service has identified highly erodible soils. The agency prepares, and makes available to the public, lists of highly erodible soil map units. The determination has been made through application of the highly erodible lands criteria (7 CFR Part 12). The criteria use two basic formulas for determining the erosion rate: that due to rain- fall and that due to wind. These erosion rates are then divided by a predetermined soil loss tolerance value.
The soil erosion rate due to rainfall is calculated by using the uni- versal soil loss equation (USLE). The USLE is a multiplication of three factors: rainfall and runoff R, the degree to which the soil re- sists water erosion K, and a factor (LS) describing the effects of slope length (L) and steepness (S). The resulting number represents the potential average annual rate of sheet and rill erosion due to rainfall.
The potential average annual rate of wind erosion is estimated by using the wind erosion equation (WEQ), which multiplies two factors: the climatic characterization of wind speed and surface soil moisture C by the degree to which soil resists wind erosion 1.
Values for all the factors used in the soil loss equations are calculat- ed, or are already contained in the soil survey information by soil map unit, using methodologies explained in the U.S. Department of Agriculture handbooks or Natural Resources Conservation Service field office technical guides and references.
The criterion for highly erodible lands, then, is the result of the rainfall or wind erosion rate calculation divided by a factor T repre- senting a predetermined soil loss tolerance. The T value represents the maximum annual rate of soil erosion that could occur without causing a decline in long-term productivity. The designation of highly erodible lands, therefore, is not based solely on actual erosion, but on the relationship of erosion rates to the maintenance of desired pro- ductivity, or use, of the land.
The evaluation of potential soil erosion impacts will focus on the amount of ground to be cleared at anyone time, the slope of ground, erodibility of exposed soils, and rainfall potential. The universal soil loss equation can be used to predict the amount of soil potentially lost to erosion, if the project warrants a detailed assessment. Soil erosion can produce a direct impact on aquatic life in surface waters through sedimentation, as discussed in the chapter on water resources.
Fortunately, most environmental analyses of potential erosion ef- fects for small, site-specific projects will be able to conclude that, with implementation of proper mitigation measures, the remaining impact will be negligible. The potential for impact, however, is important to establish the required mitigation. State-of-the-art erosion and sedi- mentation control techniques are available to all contractors and are usually contained in contract specifications in detail, including timing and staging of placement of erosion control measures related to con- struction activities. Measures may include such activities as seeding of bare slopes; provision of diversion drainage ditches; use of hay bales or straw around catch basins and drainage structures to detain soil; installation of fabric silt fencing around the area to be cleared; construction of detention basins; or limiting the amount of permitted bare ground at anyone time. Guidelines and specifications for revege- tation and erosion control practices for soil-disturbing activities can be developed on a soil-type-specific basis.
The environmental impact assessment for more comprehensive projects and actions, such as long-range management plans for exten- sive acres of national forests or Bureau of Land Management lands, may not be so easily concluded that successful mitigation of soil ero- sion impacts is possible. Plans that will set policy and specific re- quirements for many years regarding the use of land for grazing, timbering, and mining may have serious effects on soil conservation and productivity. Lands that are mismanaged because of incorrect as- sumptions or unforeseeable factors can cause irretrievable and irre- versible loss of soil resources and associated watershed or stream impacts. For this reason, long-term and geographically extensive management plans must be carefully assessed. Periodic checks and
balances must be included to permit reassessments and revisions based on changing environmental factors.
16.4 Soli Suitability
As with geologic features, the evaluation of soils-related impacts often involves assessing the suitability of soils to support the proposed activ- ity or project, or suitability of the proposed project or action given the soil characteristics of the location. For example, if soils are not appro- priate for supporting structures, or maintaining a slope without slip- page, then unsuitable soils may have to be excavated and replaced with other soils, which are then compacted to produce required sup- port characteristics. On the other hand, if existing ground is composed of fill material, it may not be a suitable location for the construction of homes or buildings. The goal of the analyst is to detennine the compat- ibility of the proposed use of land with the characteristics of the soils.
The Natural Resources Conservation Service land-use policy objec- tives, as set forth in Parts 400 to 404 of the General Manual, are as follows:
• Systematically protect agricultural land, including cropland, range- land, and forest land, from unnecessary and irreversible conversion to nonagricultural uses.
• Discourage incompatible uses of land or the construction of unnec- essary encroachments in floodplains and wetlands.
• Promote the use of land within its capabilities to protect natural re- sources and to ensure public health, safety, and welfare.
• Encourage and assist states and local governments in planning for growth and development in coastal areas to protect the coastal re- source base.
As noted in the land-use policies, soil considerations overlap with other areas of impact assessment, such as floodplains, wetlands, or coastal zones, discussed in other chapters of this text.
Legislation and regulations continue to strive for increased compat- ibility in land use with natural soil and geologic conditions. An exam- ple is the Watershed Protection and Flood Prevention Act to provide assistance for persons living in small watersheds and to provide addi- tional treatment and protection of federally owned lands within such watersheds. The Food Security Act of 1985 discontinues certain bene- fits and incentives provided by the Department of Agriculture to per- sons who produce agricultural commodities on highly erodible land or converted wetland.
Although mostly considered as a compatibility assessment, some types of projects affect the chemical or physical characteristics of the soil. Examples are poor agricultural practices, clearing of land cover that produces changes in sunlight and the moisture content of soil, or application of fertilizers or pesticides to crops. Severe soil contamina- tion also can result from spillage of hazardous materials such as fuel oil, acid mine drainage, or leachate from landfills. These types of ef- fects can render soils unsuitable for most uses.
16.5 Farmland
The protection of farmland is directly related to a concern for the rapid conversion of agricultural land, including cropland, forest land, and rangeland, to nonagricultural uses. The conservation of highly productive agricultural land and the maintenance of sustainable food production are goals consistent with the national welfare.
16.5.1 Sustainable agriculture
Sustainable agriculture refers to agricultural practices that, through the use of technology, provide for long-term sustainability of production, profit, environmental quality, and food safety. It is achieved through management strategies which help the producer select hybrids and vari- eties, soil-conserving cultural practices, soil fertility programs, and pest management programs. The goal of sustainable agriculture is to mini- mize adverse impacts to the immediate and off-farm environment while providing a sustained level of production and profit (7 CFR Part 407).
16.5.2 Legislation and definitions
The Farmland Protection Policy Act of 1981, as amended in 1987 (FPP A), has a purpose of minimizing the extent to which federal pro- grams contribute to the unnecessary and irreversible conversion of farmland to nonagricultural uses. The act defines three levels of im- portant farmland: prime farmland, unique farmland, and farmland of statewide or local importance.
Prime farmland, generally, is land that has the best combination of physical and chemical characteristics for production of agricultural crops with minimum input of fuel, fertilizer, pesticides, and labor. The Natural Resources Conservation Service actually uses a number of very specific criteria to designate soil as prime farmland. Prime farm- land can see current use in cropland, rangeland, or forest land, but is not already in, or committed to, urban development or water storage. Prime farmland already in urban use has a density of 30 structures per 40-acre area. Prime farmland committed to urban development must score 160 points or less from the land evaluation and site as- sessment criteria (discussed below).
Unique farmland is land other than prime farmland that produces specific high-value food and fiber crops. Farmland ofstatewide impor- tance is land so designated by state agencies as important in the pro- duction of crops.
Many states also have enacted specific laws and regulations for the protection of agricultural lands. These statewide requirements can be more stringent than federal requirements, and they also would apply to non-federally assisted projects. Sometimes preparation of a sepa- rate farmlands impact assessment report, for review and approval at the state level, is required. The analyst should coordinate at the earli- est possible time with state and local planners and officials to deter- mine any special study requirements.
16.5.3 FPPA criteria
The Farmland Protection Policy Act directs the Department of Agriculture to develop criteria for identifying the effects of federal pro- grams on the conversion of farmland to nonagricultural uses. The DOA's criteria are contained in 7 CFR Part 658 and consist of two parts: land evaluation criterion-relative value, and site assessment criteria.
The Natural Resources Conservation Service provides technical as- sistance to develop state and local agricultural land evaluation and site assessment (LESA) systems. Procedures for developing LESA systems are contained in the Department of Agriculture National
Agricultural LESA Handbook (U.S. Department of Agriculture, Soil Conservation Service, 1983). The LESA system is designed to deter- mine the quality of land for agricultural uses and to assess sites or land areas for their agricultural economic viability. The Handbook provides guidance on land evaluation criteria for cropland, forest land, and rangeland and on site assessment criteria.
Compliance with the Farmland Protection Policy Act is accomplished through use of Form AD-1006, the Farmland Conversion Impact Rating Form. A summary ofform information is shown in Fig. 16.1.
The first part of the criteria, the land evaluation or relative value, is established by state and local officials, with technical assistance from the Natural Resources Conservation Service. Based on soil char- acteristics, groups of soils within a local government's jurisdiction are evaluated and assigned a score between 0 and 100, representing the relative value for agricultural production of the farmland to be con- verted by the proposed project or action compared to other farmland in the same local government jurisdiction. This score is the relative value rating on Form AD-1006.
The second set of criteria for evaluation of farmland conversion im- pact, the site assessment criteria, is used to evaluate specific site characteristics of the proposed project or action. Based on the an- swers to 12 questions, a maximum score of 160 points is possible for a particular site or alternative. The criteria contained in the Farmland Protection Policy Act rule include scoring a proposed site based on consideration of these 12 factors:
Criteria Maximum total points
1. Area in nonurban use 15
2. Perimeter in nonurban use 10
3. Percentage of site being farmed 20
4. Protection pr,ovided by state and local governments 20
5. Distance from urban built-up area 15
6. Distance to urban support services 15
7. Size of present farm unit compared to average 10
8. Creation of nonfarmable land 10
9. A vailability of farm support services 5
10. On-farm investments 20
11. Effects of conversion on farm support services 10
12. Compatibility with existing agricultural use 10
Total possible points 160
For projects that have linear, or corridor-type sites, criteria 5 and 6 are eliminated and criteria 8 and 11 are scored on a scale of 0 to 25 points.
Although the example included above relates to the criteria con- tained within the Natural Resources Conservation Service guide for conformance with the Farmland Protection Policy Act, the analyst should be aware that many local areas have developed specific LESA systems for use in that particular geographic area. These local sys- tems, ifapproved by the NRCS for use in compliance with the FPPA, should be used for the site assessment portion of the analysis.
16.5.4 Interpreting results
The combined land evaluation and site assessment criteria yield a maximum score of 260 points for any particular site or alternative. The highest combined score indicates sites most suitable for protection as farmland. Sites with combined scores of less than 160 points are to be given minimal protection, and no additional sites need to be evaluated. If a site receives a score of 160 points or more, the proposed project or action must be reevaluated to consider (1) the use of land that is not farmland; (2) alternative sites, locations, and designs; and (3) special siting requirements that may preclude the use of an alternative site.
16.5.5 The process
The presence or absence of soil classified as prime farmland, unique farmland, or soils of statewide or local significance is determined through review of applicable soil surveys for the sites or locations of the proposed project or action. The project sponsor fills in part I of Form AD-1006 and forwards the form, with appropriate project alternatives descriptions and mapping, to the Natural Resources Conservation Service. Refer to Fig. 16.2 for a summary of the FPPA compliance process.
Mter review of the information on the proposed project or action, the Natural Resources Conservation Service determines if the site is farmland subject to the Farmland Protection Policy Act. The Natural Resources Conservation Service has 45 days to respond to requests for determinations of farmlands subject to the act. If the Natural Resources Conservation Service does not respond, and further delay would interfere with construction activities, the agency may proceed as though the site were not farmland.
If farmland subject to the act is involved, the NRCS returns Form AD-1006 to the sponsoring agency, with completed parts II, IV, and V, the land evaluation sections of Form AD-1006. The sponsoring agency then applies the site assessment criteria and completes parts III, VI, and VII. Based on the total combined score for relative value (land eval- uation) and site assessment criteria, the agency determines the suitabil- ity of the site for protection as farmland. A copy of the completed Form AD-lO06 must be returned to the NRCS after a decision relating to farmland conversion has been made by the federal sponsoring agency.
16.5.6 Rights of private property owners
The 1987 amendments to the Farmland Protection Policy Act clarified the issue of private ownership and the discretion of the federal agency to provide assistance to convert farmland to nonagricultural uses. The act clearly states that the federal government is not authorized to regulate the use of private or nonfederalland. In a case of a private party or nonfederal unit of government applying for federal assis- tance to convert farmland to nonagricultural use, the federal agency will apply the criteria and recommend alternatives or measures to avoid or minimize adverse effects. If the landowners want to proceed with the proposed project or action, the federal agency may provide or deny the requested assistance. The private parties or nonfederal gov- ernment unit may proceed with the proposed project or action without federal assistance.
Marriott, B. (1997). Environmental impact assessment: A practical guide. New York, NY: McGraw-Hill.
17.1 Related Legislation and NEPA Requirements
The primary federal agency responsible for the control of environmen- tal health pollutants is the Environmental Protection Agency. Several laws and regulations apply to hazardous substances and charge the Environmental Protection Agency with control responsibilities through standard setting and issuance of permits. Many of the proce- dures established to comply with legislation have been determined to be the functional equivalent of an environmental analysis required under the National Environmental Policy Act (NEPA). Much of this section of text has been summarized from results of an EP A work ses- sion comparing EP A programs with NEP A requirements (U.S. Environmental Protection Agency 1993). A summary of the laws and regulations discussed in this section is shown in Fig. 17.1a and h.
17.1.1 Solid Wastes Disposal Act
The Solid Wastes Disposal Act provides technical and financial assis- tance for the development of management plans and facilities for the recovery of energy and other resources from discarded materials and for the safe disposal of discarded materials, and to regulate the management of hazardous waste. The act incorporates and is amended by other related legislation, most recently (1987) by the Hazardous and Solid Wastes Amendments of 1984, the Safe Drinking Water Act Amendments of 1986, and the Superfund Amendments and Reauthorization Act (SARA) of 1986.
The act emphasizes the needless waste of recoverable material by burying and that methods are available to separate usable material from solid wastes. By recognizing that solid wastes represent a potential source of solid fuel, oil, or gas that can be converted to energy, the act emphasizes the need to develop alternative energy sources and finds that technology exists to produce usable energy from solid waste.
The act as amended, among other regulations, establishes
• A list of hazardous wastes
• Specific standards for generators of hazardous waste, transporters of hazardous waste, and owners and operators of hazardous waste treatment, storage, and disposal facilities, including prohibiting land disposal of specified wastes
• Permit requirements
• The relationship to surface coal mining and reclamation permits is- sued under the Surface Mining Control and Reclamation Act of 1977 to control coal mining wastes or overburden
• Site inventories required by states, to include the location, owner, type of hazardous waste, and current status
• Monitoring, analysis, testing, and reporting requirements of owners or operators
• Regulation of underground storage tanks
The standards establish requirements for such things as record keeping; labeling; container use; a manifest system to identify the quantity, composition, origin, routing, and destination of hazardous waste from point of generation to point of disposal; treatment or stor- age; and reporting to state or local agencies.
Amendments to the Solid Waste Disposal Act related to under- ground storage tanks are predominantly derived from the Hazardous and Solid Wastes Amendments of 1984. The law requires owners of underground storage tanks to notify the appropriate state or local agency of the existence of such tanks, specifying the age, size, type, location, and uses. Each state must maintain two separate invento- ries of all underground storage tanks in the state, one for petroleum and one for other regulated substances.
The underground storage tank regulations include requirements for
• Maintaining a leak detection system • Reporting releases and corrective actions taken • Taking corrective action in response to a release • Closure of tanks to prevent future releases
• Maintaining evidence of financial responsibility for taking correc- tive action and compensating third parties for bodily injury and property damage caused by accidental releases The Hazardous and Solid Wastes Amendments of 1984 additionally required a nationwide study of underground storage tanks to include
• Description of the tanks, including location, age, and type
• Soil conditions, water tables, and the hydrogeology of tank locations
• Likelihood of releases from tanks
• Effectiveness and cost inventory systems, tank testing, and leak de- tection systems
The Solid Waste Disposal Act also provides federal guidelines for state or regional solid waste plans and criteria for sanitary landfills. The objectives of this part of the act are to "assist in developing and encouraging methods for the disposal of solid waste which are envi- ronmentally sound and which maximize the utilization of valuable re- sources including energy and materials, which are recoverable from solid waste and to encourage resource conservation."
17.1.2 RCRA
The Resource Conservation and Recovery Act (RCRA) requires the Environmental Protection Agency to set standards and issue permits to develop the regulatory framework to identify those wastes that must be managed as hazardous. Under the Resource Conservation and Recovery Act, the EP A sets requirements for management of haz- ardous wastes and a system for permitting facilities that treat, store, and dispose of EPA-listed or identified hazardous wastes. Standards set under the Resource Conservation and Recovery Act must be based on the protection of human health or the environment
Hazardous waste treatment, storage, and disposal facilities are sub- ject to pennitting by the EPA. The permitting process covers the de- tails of the design and an evaluation of environmental impact of the facility. A public notice of a draft permit decision must by published by the EPA in the local area ofthe facility. Mter a 45-day public review and comment period, the EPA makes a final permit decision. Court cases have concluded that the permitting process under the Resource Conservation and Recovery Act is the functional equivalent of the
NEPA process (U.S. Environmental Protection Agency 1993). Responsibilities under the act can be delegated to the states in lieu ofthe EPA when the state has a program that is consistent with, and
at least as stringent as, the federal program.
17.1.3 CERCLA and SARA (Superfund)
The Superfund program is authorized under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act of 1986. The program sets forth two types of actions to pro· tect human health and the environment from the nation's abandoned or uncontrolled hazardous waste sites: removal actions and long·term remedial actions. Removal actions refer to short-term releases or threats of release of hazardous materials. Superfund remedial actions apply to sites on the National Priorities List (NPL), Superfund's list of highest-priority hazardous waste sites, and consist of permanently and significantly reducing the dangers, but do not necessitate removal action.
The CERCLA procedures are detailed in the National Contingency Plan and constitute a functional equivalent of NEPA compliance. These are the primary steps in the procedures:
1. Site screening and inspection. The purpose is to identify haz- ardous substances and the sensitive populations and environmen- tal features likely to be affected.
2. Hazard ranking system score. This quantitative estimation of the relative threat to humans and/or ecosystems determines whether the site is placed on the National Priority List.
3. Remedial investigation/feasibility study (Rl/FS). This study de- termines the nature and extent of contamination and evaluates proposed alternative remedies. A detailed risk assessment, includ- ing exposure pathways and toxicity levels, is required. Proposed remedial alternatives are objectively assessed by using nine evalu- ation criteria (U.S. Environmental Protection Agency 1993):
• Overall protection ofhuman health and the environment;
• Compliance with applicable, relevant or appropriate requirements;
• Long-term effectiveness and permanence;
• Reduction of toxicity, mobility, or volume through treatment;
• Short-term effectiveness;
• Implementability;
• Cost;
• State acceptance; and
• Community acceptance
4. Public review. An opportunity for review and comment by the public and interested agencies, states, or tribes is afforded. The community involvement program also includes interviews; meet- ings, fact sheets, press releases, workshops, and/or site tours as determined suitable for the specific site; and a technical assistance grant of $50,000 to local community groups, allowing them to hire an adviser who can both monitor and explain the highly complex, technical aspects of a typical cleanup.
5. Record of decision. This documents the background information on a site and describes the selected cleanup method and how it was selected. Responses to comments received during the review period are included.
6. Site visits. Every five years, the EPA visits sites where the select- ed remedy leaves contaminants at levels that do not allow for un- restricted access to ensure the remedy is still protective.
CERCLA also established the Agency for Toxic Substances and Disease Registry which conducts health assessments based on expo- sure through releases of hazardous wastes.
17.1.4 Pesticides
The Environmental Protection Agency regulates the conditions of dis- tribution, sale, and use of pesticides through authorization provided by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act (FFDCA). The proce- dures for compliance with registration of pesticide products and granting use permits are functional equivalents of an Environmental Impact Statement under NEPA. The process requires assessment of potential environmental impacts from the use of pesticide products and a public review and comment period.
17.1.5 Toxic substances
The Thxic Substances Control Act (TSCA) authorizes regulation of toxic substances including polychlorinated biphenyls (PCBs). Additional regulation of lead and asbestos is contained within the Asbestos Hazard Emergency Response Act (AHERA). TSCA provides prevention of unreasonable risks of injury to health or the environment from a chemical at any stage in its life cycle-manufacturing, processing, dis- tribution, use, or disposal. It also provides a permitting program for disposal procedures for PCBs.
The act requires preparation of risk assessment (RA) and regulato- ry impact analysis (RIA) documents to evaluate environmental im- pacts. The process includes consideration of alternatives, including chemical substitutes, pollution prevention options, process changes, and substitute products. A public review and comment period is re- quired. The permitting and regulatory procedure is thus a functional equivalent of NEP A.
17.1.6 Clean Water Act
The Clean Water Act contains numerous provisions for the protection of public and environmental health, some of which are summarized here.
The EPA establishes guidelines for development of water quality criteria by the states and sets national water quality criteria for spe- cific chemical pollutants. The national water quality criteria are based on testing to provide protection for aquatic organisms and for human health. Water quality criteria programs developed by states or tribes must contain the following:
• Use designations, which require that all waters, where attainable, be designated for propagation of fish, shellfish, and wildlife and for recreation in and on the water
• Use attainability analyses for stream segments that do not meet the goal
• Water quality criteria to protect in-stream uses • Antidegradation policy to maintain existing uses
The Section 401 water quality certification process provides an op- portunity for states, tribes, and the EPA to ensure that water quality standards are met.
Regulations for water quality planning require that states identify waters that are not anticipated to attain or maintain water quality standards and develop a priority ranking. The planning process must include development of total maximum daily loads (TMDLs) that de- fine the specific reductions in chemical and other forms of pollution necessary to protect water quality.
Section 404 of the act establishes a program to regulate the dis- charge of dredged and fill material into waters of the United States, including wetlands. Section 404 permits are discussed in greater de- tail in Chap. 18, Water Resources.
The Clean Water Act establishes the National Pollutant Discharge Elimination System (NPDES) program (also referred to as Section 402 permits). Effiuent standards and guidelines regulate industrial discharges to surface waters and to publicly owned treatment works. The limitations and standards applicable to direct discharges are implemented in NPDES permits for point sources discharging directly to the waters of the United States. The limitations are in- dustry-specific and are developed after consideration of the avail- ability and economic achievability of the technology used as the basis for the limitations. The NPDES permitting requirements, and the requirements of Section 103 of the Marine Protection, Research, and Sanctuaries Act, also apply to disposal and discharge into the ocean.
EPA's issuance of new-source NPDES permits requires an environ- mental analysis under NEPA, and an Environmental Impact Statement, if required, to address the full range of potential impacts, including changes in land use, population density, or impacts on air quality, noise, wildlife, and other resources.
17.1.7 Safe Drinking Water Act
The Safe Drinking Water Act (SDWA) mandates the EPA to establish national drinking water standards for various contaminants. It also establishes the underground injection control (VIC) regulations that set minimum standards for siting, construction, operation, mainte- nance, and closure of injection wells. Injection wells are bored, driven, or dug holes used for the subsurface emplacement of fluids. Injection practices may be categorized as deep disposal of hazardous, industri- al, or municipal wastewater; injection for enhanced recovery of oil and gas and disposal of brines and produced fluids; solution mining of minerals; or injection of hazardous or nuclear wastewaters above or into an underground source of drinking water. The purpose of the standards is to prevent injection wells from introducing contaminants into underground sources of drinking water that may cause a public water supply system to violate a National Drinking Water Standard or otherwise adversely affect human health and the environment. The permitting process addresses a range of environmental concerns.
17.1.8 Occupational Safety and Health Administration
The safety of workers is protected by laws and regulations governing public health in the workplace. The laws apply to normal operational activities and include all provisions for standard injury and illness prevention, construction requirements, and requirements for the han- dling of chemicals and prevention of infection and disease. Worker safety programs are industry-specific and ensure protection during normal operations and emergency conditions.
17.2 Hazardous Waste Studies
The analysis of potential hazardous waste impacts for a proposed project or action has three general steps requiring three separate re- ports: the initial site assessment (lSA), the preliminary site investiga- tion (PSI), and remedial investigation/feasibility study (RIIFS).
17.2.1 Initial site assessment
The ISA study is a research activity on past and present land uses in the area or potential effects of the proposed project or action. There are three basic steps:
1. Regulatory agency record review
2.Site inspection and owner interview; review of historical records
3. Report preparation
The task begins with contact with the Environmental Protection Agency and appropriate state and local environmental and health regulatory agencies to identify any known hazardous waste sites in the area of potential project or action effect. Because of the various stringent legislative requirements discussed in the previous section, inventories of hazardous waste sites are comprehensive and up-to- date. EPA will provide the CERCLIS list and the National Priorities List. Requests for an "environmental audit research," government records report, or similar terminology from appropriate state or local agencies should yield a report covering the following:
• Permits to generate hazardous waste and/or handle hazardous ma- terials and/or maintain an underground storage tank
• A log of reports of releases or threatened releases with potential for injury or groundwater contamination, by date
• A log of the agency hazardous materials team responses and inci- dents
• Underground storage tank removal permits
• Underground storage tank cleanup logs and record of tank leaks
• State list of identified hazardous waste sites
• State toxic substance control program information system
• EPA CERCLA site and event listing
Available information will include types of problems, the list of cont- aminants involved, status of investigations or cleanup, and recom- mended remediation. The state and/or local water resources and quality control boards or agencies should be contacted for groundwater quality information in test wells or nearby private or municipal wells.
Past and present land uses are determined through review of his- toric maps, coordination with local officials, site inspections, and in- terviews with property owners. For example, an ISA prepared for a project in San Bernardino, California, used Sanborn Fire Insurance maps from 1894, 1906, and 1950 and aerial photographs from 1965, 1972, 1979, and 1986 to determine past land uses in a project area for a proposed highway-widening project.
Field inspections to identify potential hazardous waste sites or ma- terials will include a search for such elements as storage structures, pipelines, landfills, surface staining, oil sheen, odors, vegetation damage, or possible materials such as asbestos, paint, fireproofing, or pipe wrap. Existing land use and an interview with the owner or operator will yield additional information on possible storage structures, cont- amination, or hazardous materials.
The result of an ISA is a conclusion about the existence of a known or potential hazardous waste site. The report provides the basis for considering the next steps in the process. The best option is to review proposed alternatives to ascertain if the hazardous waste site can be avoided through changes in location, design, or characteristics. If not, the process proceeds to a preliminary site investigation, which can be time-consuming.
17.2.2 Preliminary site investigation
The purpose of the PSI is to determine whether hazardous waste is actually present through field testing, sampling, and laboratory analysis for contaminants. Testing normally includes soil samples, core borings, soil gas probes, and sometimes test wells to check for groundwater contamination. If hazardous waste is present, the inves- tigation should identify the type and level of waste present, limit of contamination, and estimated costs for remediation.
Upon identification of a hazardous waste site, the appropriate state and local regulatory agencies should be notified with a request that the owner of the property be notified of the contamination. It is the responsibility of the property owner or other potentially responsible party to characterize the hazardous waste site and, where appropri- ate, to remediate the contamination.
The PSI report should include the detailed methodologies, studies, and remedial actions. The environmental document should contain a summary of the investigation, written in easily understood language. The environmental document should contain the following:
• A map showing the location of the sites
• A description of the contaminants, level of contamination, and fed- eral and state maximum levels for the contaminants
• Alternatives that avoid the hazardous waste and why such avoid- ance is not practicable
• Potential remedial actions
• Results of coordination with appropriate regulatory agencies
• Status of investigation, including potential costs and time estimate to complete remedial actions
• The procedure to be followed should any hazardous waste or mater- ial not previously identified be discovered during construction
The above information for each proposed alternative becomes a con- sideration in the selection of alternatives. After an alternative is se- lected, the final environmental document should describe results of all coordination with regulatory agencies and whether the responsible party has been identified and has agreed to remediate the contamina- tion.
17.2.3 Remedlallnvestlgatlonl feasibility study
During the final design stages of the proposed project or action, efforts should be made to avoid or minimize impact with hazardous waste sites. A comprehensive investigation is required for all hazardous waste sites which cannot be avoided. The RIIFS determines the characteris- tics and extent of the contamination and develops a detailed hazardous waste management plan which recommends the most cost-effective method of remediation. Here are examples of remedial actions (Los Angeles County Metropolitan Transportation Authority 1993):
Containment barrier-install vertical dike to block horizontal move- ment of contaminant.
Cap site-install horizontal impermeable layer to reduce rainfall in- filtration.
Excavate and dispose-remove contaminated soil and dispose in an approved site.
Excavate and treat-remove contaminated soil and treat (includes spreading and land farming).
Remove free product-remove floating product from water table. Pump and treat groundwater-generally employed to remove dis-
solved contaminants.
Treatment at hookup-install water treatment devices at each dwelling or other place of use.
Enhanced biodegradation-use of any available technology to promote bacterial decomposition of contaminants.
• Replace supply-provide alternative water supply to affected parties.
• Vapor extraction.
• Vent soil-bore holes in soil to allow volatilization ofcontaminants.
A valuable source of information on remediation is the u.s. Geological Survey (USGS). The USGS provides technical assistance and research to other federal, state, and local agencies in many areas of expertise, as already discussed in Chap. 16.
USGS recent research in assessing the potential for contamination of groundwater and remediation of contaminated sites includes a modified groundwater flow model to determine vapor flow above the water table. The model can be used to detennine optimal placement of wells and pumping rates to extract contaminants with the greatest efficiency. Another example is the USGS continual research on public health contaminants in groundwater, such as herbicides from central U.S. agricultural lands, and in surface water, such as the assistance in issuing a public health advisory in Washington state for fish con- sumption based on USGS studies of DDT in agricultural soil, stream water, stream sediment, and fish tissue in the Yakima River (U.S. Department of Interior, USGS 1995b).
The USGS also has conducted research on the use of natural and enhanced bioremediation techniques to degrade organic compounds soils. Microorganisms naturally found in soils are active consumers of fuel-derived toxic compounds and can transform the compounds into harmless carbon dioxide (U.S. Department of Interior, USGS 1995c).
If the remedial action recommended in the RIIFS is significantly different from the actions listed in the final environmental document, then a supplemental environmental document may be required.
17.3 Use of Scoping to Identify Issues and Concerns
Engineers, planners, and environmental health specialists will know of potential real risks likely to be associated with any particular pro- posed project or action. The abundance of strictly enforced regulations and permitting processes ensures against public health risks.
Just as important, however, is the public's perception of what the health and safety risks may be, whether the concerns are founded or unfounded in fact. It is therefore extremely important that the envi- ronmental document specifically address any issues and concerns raised by the public. Failure to recognize the importance of public perception can lead to catastrophic results in subsequent planning phases. The fact that a particular concern is raised by the public is, in itself, a reason for a thorough discussion within the environmental document. Applicable regulations and the incorporation of required prevention measures should be explained for each issue raised. In some cases, public input may reveal information on local conditions or historical events that would otherwise not be known by the environ- mental analysts.
As an example, the following environmental health and safety con- cerns were identified in the public scoping process for a proposed mu- nicipal solid waste landfill involving transport of the waste via rail
(u.s. Department ofInterior, BLM, 1995):
• Hazardous materials in the waste stream
• Vectors transported with the wastes
• Fires at the landfill
• Use ofleached-ore residue for landfill cover
• Interference with aircraft using a nearby aerial gunnery range
• Contaminationofgroundwater
• Transport train delays
• At-grade railroad crossings
• Train accidents
• Highway safety on local roads during peak tourist season
Each of these issues was addressed in the environmental studies and discussed within the Draft Environmental Impact Statement.
17.4 Mitigation
Discussions of environmental health and safety issues within an envi- ronmental document normally consist of a description of mitigation measures. The numerous regulatory and project design measures in- corporated into the project will most likely lead to a conclusion of no significant impact with installation and implementation of mitigation measures. Individual measures are far too numerous, complex, and project-specific to be listed in this text, but descriptions should be in- cluded within the environmental document for a particular project in sufficient detail to offset public concerns.
Marriott, B. (1997). Environmental impact assessment: A practical guide. New York, NY: McGraw-Hill.
18.1 Groundwater
The study of groundwater resource impacts is closely related to stud- ies of geology and soils. Productive interaction of various members of the multidisciplinary team is necessary to ensure that all important characteristics are noted and all possible impacts are considered.
18.1.1 Existing characteristics
Relevant infonnation on groundwater characteristics of a study area can be determined through coordination with local water manage- ment districts, water quality agencies, or municipal water suppliers. State Stormwater Management Acts require watershed management plans or water quality control plans for groundwater basins. These plans will identify particularly sensitive groundwater issues. Review oflocal or regional water quality control or management plans will in- dicate most recent data on water supply, volume, flow, quality, use, and future goals and objectives. Extensive infonnation on surface and groundwater flow and quality also is available from the USGS.
The USGS provides water supply and quality infonnation through a national assessment program designed to study water quality in rep- resentative basins covering more than 50 percent of the United States (U.S. Department of Interior, USGS 1995a). The USGS-developed mathematical model of groundwater flow has become a widely used computer-based model in the groundwater industry (U.S. Department of Interior, USGS 1995e). For example, USGS programs in California (U.S. Department of Interior, USGS 1995i)
• Assess water resources quantity and quality throughout the state
• Assist water management agencies in southern California in the study of using aquifers for storage and use of reclaimed wastewater for groundwater recharge and irrigation
• Develop water management programs to characterize hydrogeologic conditions in areas that appear to have good potential for water banking (recharging groundwater systems for future pumping), and to optimize combined use of surface and groundwater, control of water levels in an urban area subject to liquefaction during a major earthquake, and containment of groundwater pollutants from Environmental Protection Agency Superfund sites
• Develop management strategies for controlling seawater intrusion into coastal aquifers
The USGS data are stored in the national Water Data Storage and Retrieval System (WATSTORE), which includes a daily-values file that contains 300 million observations of stream flow, water quality, sediment discharge, and groundwater-level data; a water quality file that contains 4.1 million surface and groundwater analyses; a peak- flow file that contains nearly 600,000 observations of annual peaks of stream flow and river stage; and a groundwater site inventory file that contains information for more than 1.4 million wells. Much of this information has been made available over the Internet (U.S. Department of Interior, USGS 1995d).
The USGS also operates the National Water-Use Information Program used to collect, store, analyze, and disseminate water-use in- formation nationally and locally to a wide variety of government agen- cies and private organizations (U.S. Department of Interior, USGS 1995g).
Water quality control plans identify uses of groundwater supplies, such as municipal and domestic, agricultural, industrial services, and/or industrial process. Use characteristics within the basin are described. Specific water quality objectives, or standards, are compared with re- cent and historical quality testing results from monitoring wells.
The major water-bearing geologic formations (aquifers) are identi- fied as related to soils and geologic information. Flow and quantity characteristics of groundwater resources are dependent on local sur- face and geologic conditions. In areas of faults and historic fault activ- ity, impermeable vertical and horizontal restrictions to groundwater flow may occur. In limestone are~s, subsurface caverns and streams may determine groundwater characteristics.
Natural and/or created groundwater recharge areas should be noted on mapping. A recharge area is the area in which water reaches the zone of saturation (groundwater) by surface infiltration. Information will likely be available in local or regional water management plans on the principal sources of groundwater recharge. If the source is precipita- tion, how much of the average annual rainfall is available for recharge? Other sources may include subsurface inflow, seepage from streams and rivers, or artificial recharge. In some areas of California, for example, recharge facilities known as conservation basins have been constructed. These basins are filled through use of diverted local stream flow and from water imported through the California Aqueduct State Water Project. Drywells also can be used to percolate drainage water.
Other information on groundwater recharge may be available from county or regional flood control or water conservation districts. A local or regional hydrology manual will contain specific hydrologic soil classifications based on infiltration rates.
18.1.2 Groundwater impacts and mitigation
Effects on groundwater may be direct, indirect, physical, or chemical. Direct, physical impacts could include loss of wells, interception of the water table, or other physical changes through earthwork, blasting, etc. that alter flow, recharge, or other hydrologic conditions. Depending on the type of project proposed, a physical interception of the water table may, in turn, require continual dewatering through pumping. Dewatering can cause localized drawdowns of the water table elevation and adversely affect local wells.
Substantial new demand and use of groundwater can cause local or regional drawdowns. For example, a new housing project with indi- vidual residential wells, or a system of community wells, may ad- versely lower the water level and available groundwater supply at nearby existing housing developments that also depend on residential wells. If the water level is lowered by deeper new wells below the level of existing wells, those residences on existing wells will be with- out water. Figure 1S.1 illustrates how groundwater wells can affect the flow of groundwater by lowering water levels in an area around the well, known as the zone ofinf7.uence or cone ofdepression. The full recharge area of a well is often called the zone ofcontribution.
Of special concern in coastal areas is the potential for urban de- mand on groundwater to lower the existing water table to a degree to upset the subsurface balance in flow between freshwater and salt water. An adverse infiltration of salt water into underground fresh- water supplies can produce serious regional impacts.
Another potential impact of groundwater withdrawal in particular geographic areas is increased risk of land subsidence. Land subsi- dence due to pumping of groundwater occurs in nearly every state (U.S. Department of Interior, USGS 1995e).
Another factor affecting groundwater supplies is the creation of im- pervious surfaces within the recharge area. This type of impact occurs with projects involving large areas of pavement or a significant num- ber of buildings. By covering the recharge area with impermeable surfaces, the projects reduce the total area available for water perco- lation through the soils to underlying aquifers. The same impact would occur for flood control channels that are entirely paved. For this reason, many artificial river and stream channels are construct- ed with paved sides and natural bottoms.
A common approach to evaluation of potential recharge-area im- pacts is to compare the created impervious surface with the total for the watershed. Unfortunately, the same argument is sometimes made for two entirely different situations. One logic used is that the existing watershed is so large and undeveloped, with such a large pervious recharge area, that a small increase in impervious surface would not significantly affect the quantity of groundwater percolation. The other logic is that the watershed is already urbanized to such an extent that the increase in impervious surface, when compared with the total sur- faced area, would add an insignificant contribution. So it seems that the two extremes of developed and nondeveloped watersheds would not be affected by small amounts of new impervious surface, and that the only impacts would occur in partially developed watersheds.
Although the logic above is most likely applicable for the two cases stated, the analyst must also consider the possible cumulative effects of a particular project or action. Groundwater recharge areas are sel- dom lost all at once. Small amounts of impervious surface are added little by little, each with no significant impact, until there is a signifi- cant overall effect. Whenever possible, even the smallest project should attempt to incorporate detention ponds or other mitigation measures to detain water and permit maximum recharge within the remaining pervious surface.
An increase in impervious surface can contribute to groundwater quality impacts as well as quantity. Possible water quality effects on groundwater may include increases in suspended solids from erosion or in chemical contaminants through rapid runoff from impervious sur- faces. If runoff picks up pollutants such as herbicides, fertilizer, oil, gas, metals, organic or inorganic compounds, or deicing salts, these can move more rapidly into groundwater aquifers in higher concentrations.
The possibility of groundwater contamination can be increased by projects that require excavation within sensitive geologic areas. Geologic characteristics of a particular area, such as rock fractures, sinkholes, solution channels, or shallow soils, may contribute to a di- rect flow of contaminants into local aquifers. Such an impact would be most critical in areas of low groundwater recharge and yield, where dilution and flushing would be minimal.
Mitigation of potential groundwater impacts is best approached through coordination with appropriate officials and an analysis of consistency with water conservation plans and water quality control plans. Geologic voids can be filled or capped, and soil cover can be added to areas of exposed rock. Other measures would apply to both groundwater and surface water quality and may include such project- specific techniques as installation of oil and grease separators in large parking lots. Vegetated swales, drainageways, and created wetlands with extended detention also may be used to filter sediments and con- taminants from drainage.
As with surface waters, groundwater resources may be put at in- creased risk by certain projects to catastrophic events, such as spills of contaminants or hazardous materials. Each proposed project or ac- tion should be examined in terms of the probability of such an occur- rence versus the magnitude of the possible impact. Mitigation may be to require maintaining cleanup equipment on site or to establish spe- cial emergency response teams.
When fuels, pesticides, fertilizers, sewage, solvents, and other sub- stances enter the soil, the contaminants percolate through the soil to groundwater resources. Mitigation may be in the form of using com- puter models to monitor groundwater flow to determine the optimal placement of wells and pumping rates to extract contaminants.
Another form of mitigation, particularly for sites that may have pre- viously been contaminated, is bioremediation. The Superfund legisla- tion (CERCLA) prompted the authorization of the Toxic Substances Hydrology Program by the USGS. The program consisted of systemati- cally investigating the most important categories of wastes at sites throughout the United States. One of the principal findings was that microorganisms in shallow aquifers affect the fate and transport of virtually all kinds of toxic substances (U.S. Department of Interior, USGS 1995b). Microorganisms naturally present in the soils can ac- tively consume fuel-derived toxic compounds and transform them to harmless carbon dioxide. The rate of biodegradation can be greatly in- creased by stimulating the natural microbial community through the addition of nutrients.
Examples of successful bioremediation projects (U.S. Department of Interior, USGS 1995b) are summarized below to show the types of pollution that can occur and the remediation techniques.
A pipeline carrying crude oil burst and contaminated the underly- ing aquifer. The natural microbial population caused the plume of contaminated groundwater to stop expanding after a few years, without human intervention.
A sewage effiuent plume due to disposal of sewage effiuent in septic drain fields caused nitrate contamination in a shallow aquifer. Denitrification was rapidly accomplished by microbial populations.
Chlorinated solvents have been successfully used by microorganisms as oxidants, which remedies solvent contamination of groundwater.
Biological and nonbiological processes have been shown to degrade pesticide and nitrogen fertilizer contamination.
Studies of gasoline-contaminated sites have shown the importance of processes in the unsaturated zone (the zone above the water table) in degrading contaminants.
In Florida, creosote and chlorinated phenols leaked to the underly- ing aquifer through unlined ponds and were transported toward Pensacola Bay. Studies showed that microorganisms can adapt to extremely harsh chemical conditions and that microbial degrada- tion was restricting migration of the contaminant plume.
18.1.3 Sole-source aquifers and other special conditions
Sensitive aquifers and the specific recharge areas and characteristics should be identified. A sole-source aquifer is an aquifer which is the sole or principal drinking water source for an area and which, if conta- minated, would create a significant hazard to public health. Sole-source aquifers are designated and protected under Section 1424(e) of the Safe Drinking Water Act. Any designated critical aquifer protection areas (CAPAs) within the sole-source aquifer or recharge area in the area of potential effect of the proposed project or action should be identified. Early coordination regarding sole-source aquifers is required with the Environmental Protection Agency, which will review proposed alterna- tives and offer opinions on possible impacts. A separate report is nor- mally prepared at the draft environmental document stage when other technical analyses are being conducted. The potential impacts of all proposed alternatives on the sole-source aquifer should be comparative- ly discussed. If the selected alternative involves a sole-source aquifer, the final environmental document must contain appropriate analysis and consultation results to ensure that the proposed project or action will not contaminate the aquifer (40 CFR Part 149).
Other regulatory requirements that may apply include wellhead
protection areas as authorized by the 1986 amendments to the Safe Drinking Water Act. Each state must develop wellhead protection plans to protect groundwater that supplies wells and well fields that contribute drinking water to public water supply systems. The select- ed alternative of the proposed project or action must comply with these plans. Such documentation must be included in the final envi- ronmental document.
In some areas where agricultural land use is dominant, pest man- agement zones may have been established. These designated zones are areas where pesticides have been found in groundwater and thus future spraying is prohibited.
18.2 Municipal Water Supply and Wastewater Systems
In urban and suburban areas, it is important to detennine the major source of potable water: a municipal system or local wells. The source of municipal supply systems and whether the water quality from active wells or surface waters meets standards, or is treated to do so, should be noted. Public water supply standards are established by the Environmental Protection Agency as authorized by the Safe Drinking Water Act. Contained in 40 CFR Parts 141 to 143, the National Primary and Secondary Drinking Water Regulations establish nonenforceable health goals [maximum contaminant level goals (MCLGs)] and enforce- able maximum contaminant levels (MCLs) for numerous organic and in- organic pollutants. In rural areas, the primary aquifer source for wells should be described in terms of yields and physical and chemical charac- teristics.
The wellhead protection program of the state will identify wellhead protection areas, sources of contaminants, management approaches, contingency plans, and other valuable information on groundwater supplying public water supply systems.
Area wastewater systems also should be identified, including re- gional facilities' plans, particular characteristics of treatment plants serving the proposed project or action, and current capacity compared with quantities. Wastewater reuse within the basin may be important depending on the type of project being assessed. As discussed in Chap. 17, wastewater treatment plants are required as part of the Clean Water Act NPDES permit to meet established effiuent quality standards. Requirements consist of both numerical values and period- ically reporting the average or maximum values.
18.3 Surface Water
Many of the potential surface water impacts (Fig. 18.2) will be the same as potential groundwater impacts, such as a possible increase in suspended solids from erosion or chemical contamination from runoff. The same is true for subsequent discussions in this text related to floodplains, coastal areas, and wetlands. Surface water studies also include consideration of the aquatic biotic community and of recre- ational and commercial uses.
18.3.1 Existing characteristics
In addition to the sources of information discussed in the section on groundwater, surface water quality and aquatic community data may be available from the U.S. Department of Interior, Fish and Wildlife Service, state departments of environmental resources; or fish and game, river basin commissions, or local boating and fishing organiza- tions. The USGS information on surface waters may include results of chemical and biological testing as well as detailed flow information col- lected at gaging stations. For example, surface water discharge (flow) data was collected by the USGS at 10,240 stations in 1994; surface water quality data was collected at 3098 stations (U.S. Department of Interior, USGS 1995d).
Water quality standards for surface waters are normally set by state or local agencies and are based on use classifications. Examples of uses include water contact recreation and aquatic life; natural trout waters; and recreation (stocked) trout waters. Depending on the designated use for a particular section of stream or river, maximum permitted concentrations of water quality pollutants will be estab- lished, such as acidity (as measured in pH), alkalinity, biological oxy- gen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), dissolved solids (DS), nutrients (nitrates and phos- phates), fecal coliforms, and toxic substances (heavy metals, etc.).
As appropriate based on the results of scoping, the environmental document should include a mapping of major surface waterways, water bodies, and watersheds. Existing data should be summarized and compared with applicable water quality standards. Historic trends and sources of pollutants should be described. For proposed projects or actions requiring detailed water resource studies, informa- tion is usually contained in a supporting technical report and summa- rized in the environmental document.
For proposed projects or actions where surface water impact is a key issue and no available data exists for local resources, a stream or lake survey may be conducted by the study team. Such surveys include sampling over a period of time (one year is the best minimum to en- sure all seasons) of water quality and aquatic life. Physical conditions noted at each sampling station include such factors as bottom type, bank cover, percentage of shade, pool and riffle sequence, water tem- perature, and pH. Water samples are collected for analysis in the labo- ratory for water standard parameters. Bottom-dwelling (benthic) macroinvertebrates also may be systematically collected. Benthic macroinvertebrates, such as tube worms, mollusks, and larvae of stoneflies, mayflies, caddisflies, and beetles, are commonly used indica- tors of water quality. The established benthic community-species composition, quantity, and diversity-yields an abundant amount of information on water quality and condition of streams, rivers, and lakes. Fish sampling also may be included through use of seining or electroshocking.
The presence of any state or federal endangered, threatened, or designated sensitive aquatic plant or animal species should be identi- fied through coordination with the Fish and Wildlife Service, National Marine Fisheries Service, and appropriate state agencies.
18.3.2 Surface water impacts and mitigation
The ability to assess potential effects on surface water resources re- quires a thorough understanding of the physical and operational characteristics of the proposed alternatives of the project or action. The analyst must be knowledgeable about the construction phase, op- erational phase, and exactly what physical changes to existing sur- face water resources are a component of the alternatives. Impacts can then be comparatively assessed based on the level of design detail available.
Construction (short-term) effects. The primary impact associated with construction activities is usually erosion and sedimentation effects. Stream and lake sedimentation and turbidity loading can cover bottoms with silt and destroy benthic organisms. This in turn can elimi- nate food supplies for particular species and totally upset the balance of the aquatic ecological system.
Some projects may require direct in-channel work during construc- tion activities, or alteration of the surface water channel or shoreline. Channel relocations are more specifically addressed in the next section of this chapter. Direct channel disturbance results in a temporary loss of habitat and bottom-dwelling species. Compaction of stream bottom habitat by construction equipment can permanently degrade the abili- ty to support aquatic vegetation or bottom-dwelling organisms.
The other impact associated with construction activities is that runoff from construction sites will contain water quality contami- nants. Runoff impacts are further discussed in the long-term impacts section of this chapter. The probability of spills of hazardous materi- als directly into water bodies should also be considered.
As discussed in greater detail in Chap. 16, installation of proper erosion control measures can normally mitigate construction-related erosion impacts successfully. Often a requirement is that final design of the selected alternative contain specific erosion and sedimentation control plans. These plans undergo a series of approvals and permits depending on the specific state or local requirements.
Another example of required procedures to minimize impact is a water construction permit that may limit the time of year for any in- stream work, based on the feeding, nesting, or breeding requirements of sensitive aquatic species. Equipment stream crossings should be conducted with minimal disturbance, on rock fills with many pipes to permit natural water flow. Removal should return the bottom to nat- ural compaction characteristics.
The Clean Water Act requires preparation and submission of a gen- eral construction activity stormwater permit before construction is begun. The permit requires preparation of a stormwater pollution prevention plan. The plan is based on the use of best management practices (BMPs). BMPs applicable to construction sites include mea- sures to prevent erosion, prevent pollutants from the construction material from mixing with stormwater, and trap pollutants before they can be discharged.
The plan also contains requirements for the construction contractor to prepare and implement a hazardous materials management plan to reduce the possibility of chemical spills or releases to drainage channels. Proper material handling, storage, and disposal protocols are established and enforced.
Channel relocations. Long-term changes to course, current, or the cross section of the channel or its floodplain may be included as part of the proposed project or action. Sometimes exact design characteristics may not be known prior to the final design stages. The compara- tive analysis of proposed alternatives at the draft environmental doc- ument stage should be accomplished with as much detail as possible, however, to permit inclusion of this important potential impact in the decision-making process.
Many miles of streams in the United States have been lost due to stream channelization. Old practices often consisted of straightening streams into short sections of totally paved channels or culverts. The environmental impact assessment process over the past decades and the agency coordination it has fostered have made enormous changes in the manner in which stream relocations are conducted.
Stream channelization often is associated with linear projects, such as highways or railroads, with an engineering need to occupy relative flatlands. In hilly or mountainous areas, the only relative flatland may be that associated with a stream and its floodplain. Often the comparison of effects of valley floor alternatives with hillside alterna- tives centers on the relative damage of large, destructive cuts and fills on the hillsides versus fill and stream relocation, floodplains, or wetland impacts on the valley bottom.
The assessment of stream channelization impacts normally begins by comparing the length of the natural stream to be destroyed with the length of the new channel. The stream channel to be destroyed is surveyed, noting important physical, chemical, and biological features. The most obvious impact is the loss of all aquatic habitat, streamside vegetation, and benthic organisms within the destroyed channel. This impact should be quantified within the environmental document as a direct impact of the proposed project or action. The loss should be eval- uated based on the sensitivity of the stream, aquatic habitat, endemic species, and designated uses.
In all cases, the goal should be to design the new channel to main- tain the same stream length. A loss oflength and meanders into a rel- atively straight channel creates disturbances to the natural dynamics of water flow. Velocity will increase, causing upstream scouring and downstream deposition. Channel sides will be under constant erosion pressure as the stream flow tries to reach its former equilibrium. Changes in velocity can be estimated based on comparison of old and new channel lengths and flow characteristics of the stream. Degree of upset to the natural stream flow dynamics can then be estimated.
Discharge of dredge or fill material within streams, wetlands, or other waters of the United States requires a U.S. Army Corps of Engineers (Corps) Section 404 (Clean Water Act) permit. Details of the permit application information and process are contained within 33 CFR Parts 320 through 330. Section 404 permits are further dis- cussed in Sec. 18.4 of this chapter. Other permits or regulations that may apply are those of the Rivers and Harbors Act of 1899. Under this act, Section 9 permits apply to crossings of navigable waters of the United States. Section 9 permits are issued by the Corps for dams and dikes and by the Department of Transportation, U.S. Coast Guard, for bridges and causeways. Section 10 of the act requires a permit for various types of work performed in navigable waters, in- cluding stream channelization, excavation, and filling.
Sections 9 and 10 of the Rivers and Harbors Act apply to navigable waters of the United States, while Section 404 of the Clean W ater Act applies to waters of the United States. Waters of the United States mean more than navigable waters-they include floodplains and wet- lands.
The Fish and WildlifE: Coordination Act requires consultation with the Fish and Wildlife Service and the state agency responsible for wildlife resources for any modification to a stream channel or other body of water. The environmental document should contain a description of the uses of the stream or body of water and an analysis of impacts to fish and wildlife resulting from loss, degradation, or modification of habitat.
Mitigation of stream channelization impacts includes such mea- sures as ensuring no net loss in stream length (that is, new channel same length as natural channel); natural bottoms as opposed to con- crete channels; shape of concrete channels (trapezoidal) to maintain low-flow conditions; wide channel bottoms to permit stream to cut its own meandering stream course; and stabilization of outside curve banks with rock placements.
Rocks and gravel can be placed randomly within the new channels to encourage rapid naturalization of the streambed and development of a pool and rime sequence. Stream banks should be stabilized before diverting the flow of the stream from the old to the new channels.
Continuing (operational) impacts. Erosion and sedimentation effects should not be ignored as potential continuing impacts of a proposed project or action, particularly if the action is a management plan for large geographic areas or a land-use plan for municipal areas. The evaluation of alternatives for long-term plan components must in- clude an assessment of the possible secondary effects of long-term permitted uses, such as timbering techniques, grazing, mining, or continued growth in housing and development. Such activities can cause loss of vegetation and exposure of bare ground within water- sheds and associated erosion and stream sedimentation effects.
Potential long-term erosion and sedimentation effects can best be mitigated through incorporation of effective control and restoration requirements within the planning documents. These required mitiga- tion measures should be applicable to all permitted activities through the use of permits or approvals prior to project implementation. Mitigation, to be effective, must include proof of funding sources for implementation of the committed measures.
Continuing, long-term water quality effects are mostly related to discharges of runoff from paved surfaces. An increase in impervious strata produces a proportionate increase in the amount of runoff car- rying pollutants. This type of impact is discussed in Sec. 18.1.
Highway projects are used as an example of types of impact assess- ment required. Stormwater runoff containing vehicle-generated high- way pollutants enters local drainage systems and, at bridges, can directly enter streams, rivers, or lakes.
Several studies have been conducted to develop methodologies for predicting highway runoff impacts on surface water quality (U.S. Department of Transportation, FHWA 1985; Lord 1987; California Department of Transportation 1982). For example, highway runoff constituents shown to be statistically correlated to traffic have been identified as particulates, total nitrogen, lead, zinc, and chemical oxy- gen demand.
Methodologies include use of formulas and assumptions on pollu- tant deposition per vehicle, rainfall amounts, and runoff coefficients for the paved surface. A worst-case analysis assumes that highway runoff is discharged directly into a receiving stream, with no inter- vening soil, vegetation, or dilution from convergence with additional sources. Calculations can be made by entering data on average daily traffic volumes and area of paved surface. Results, after several stages of calculation, will be in flow-weighted concentrations in mil- ligrams per liter for various pollutants, such as lead, zinc, filterable solids, chemical oxygen demand, and total nitrogen. These concentra- tions can be directly compared to effluent standards. The results could also be refined based on the volume of water in the receiving stream, the dilution factor, and compared with water quality stan- dards established for the stream or river for protection of human and aquatic life, and based on designated uses.
Water quality limits set in the NPDES permit provide the basis for application and enforcement of surface water quality standards and objectives. The NPDES permit requires monitoring (testing) of the ef- fluent and of the receiving waters upstream and downstream of the discharge.
Accidental spills of hazardous materials are always a risk with transportation systems, including highways, railroads, and naviga- tion systems. As discussed in the section on groundwater impacts, the possible magnitude of impact of such spills can be devastating, as demonstrated by coastal and marine life impacts of oil spills from tankers. The probability of such spills, however, is low.
Water quality impacts are not necessarily associated with paved surface runoff. Runoff from agricultural lands or such uses as golf courses can transport fertilizers and pesticides to receiving streams and rivers. Grazing or dairy land uses can contribute significant amounts of nutrients and animal coliform bacteria.
Industrial uses can contribute toxins or heavy metals directly into surface waterways. Some processing plants or nuclear reactors can emit effiuent with significantly higher temperatures than the receiv- ing waters, causing corresponding impacts on aquatic life.
Another important potential impact on surface waters is the possi- bility of secondary and/or cumulative impacts. If the proposed project or action places stress on a particular geographic area for growth, water quality impacts related to that future growth must be assessed to the degree possible with available information. If a project will fa- cilitate and accelerate the rate of development and suburbanization, such growth in turn will increase impervious surface, accelerate dis- charges of polluted runoff, and increase stream channel erosion and sedimentation. Pressures may also be placed on existing treatment plants or water demand facilities.
Water quality impacts of runoff can be mitigated through use of stormwater runoff regulations. Stormwater management practices under such regulations may include
• On-site infiltration
• Flow attenuation by open vegetated swales and natural depressions
• Stormwater retention structures
• Stormwater detention structures
These measures can significantly reduce pollutant loads and control runoff.
Mitigation measures for stream or watershed impacts may include restoration projects for nearby, previously degraded watersheds or streams.
A Clean Water Act Section 401 water quality certification, issued by the appropriate state agency, is required for proposed projects or actions potentially affecting water quality. The certification ensures compliance with established effiuent guidelines and standards.
Recreational and commercial uses. The evaluation of potential surface water impacts must include consideration of recreational and com- mercial uses and the possible impact of the proposed project or action on such uses. Existing uses should be described and quantified to the extent possible. Impact assessment should include such items as boating and passive access, hunting restrictions (waterfowl), aesthetic
qualities, and possible degradation of fisheries or other commercial products through water quality pollution. Coordination with appro- priate state and local agencies, sporting clubs, etc., should be docu- mented.
18.3.3 Wild and scenic rivers
The Wild and Scenic Rivers Act provides for preservation of free-flow conditions of certain selected rivers of the nation and protection of those rivers' immediate environments for the benefit and enjoyment of present and future generations. Th be eligible for the National Wild and Scenic River System, a river must be free-flowing and must pos- sess outstandingly remarkable scenic, recreational, geologic, fish and wildlife, historic, cultural, or other similar values. The act required river studies to be conducted by the Department of Interior (Fish and Wildlife Service, Bureau of Land Management, or National Park Service) or Department of Agriculture (Forest Service) for all rivers, or river segments, potentially eligible for the system. Eligible river segments are classified according to the extent of evidence of human activity as wild, scenic, or recreational. Specific eligibility criteria apply to each classification. Each designated section of river on the system has a management plan, including principles, kinds and amounts of public use, and specific management measures.
The act protects rivers listed on the Nationwide Rivers Inventory and those that may be potentially eligible for listing. Coordination is required prior to any action that may foreclose a river's inclusion in the system.
Follow these steps to comply with the Wild and Scenic Rivers Act:
1. Determine whether the proposed project or action could affect an inventory river by checking the current regional inventory lists.
2. Assess potential adverse effects on the natural, cultural, and recre- ational values of the inventory river segment. Any action which could alter the river segment's ability to meet the eligibility and classification criteria should be considered an adverse impact.
Actions which diminish free-flowing characteristics or actions which increase the degree of evidence of human activity, that is, level of development, could prevent qualification or change classifi- cation. Adverse effects may occur under conditions that include
• Destruction or alteration of all or part of the free-flowing nature ofthe river
• Introduction of visual, audible, or other sensory intrusions which are out ofcharacter with the river or alter its setting
• Deterioration ofwater quality
• Transfer or sale ofproperty adjacent to an inventoried river
3. Determine whether the proposed project or action could foreclose options to classify any portion of the segment as wild, scenic, or recreational river areas. This mostly refers to actions that may cause a downgrade in classification based on increased evidence of human activity.
4. Incorporate avoidance and mitigation measures into the proposed project or action to the maximum extent feasible.
The draft environmental document must include evidence of coordi- nation with the agency responsible for managing the listed or study river (Fish and Wildlife Service, Bureau of Land Management, National Park Service, or Forest Service). If an adverse impact is anticipated, the draft environmental document must fully consider avoidance and mitigation measures for each alternative that may affect a segment of designated or proposed scenic river. If a selected alternative has po- tential adverse effects, the Finding of No Significant Impact or Final Environmental Impact Statement must identifY committed measures to avoid or mitigate adverse effects, with documentation of concurrence with the managing agency.
Publicly owned segments of designated wild and scenic rivers are also protected by Section 4(0 of the DOT act of 1966. This act applies to transportation use of park, historic, and recreational land and is discussed in Chap. 10.
18.4 Section 404 Permits
Section 404 of the Clean Water Act establishes a program to regulate the discharge of dredged and fill material into waters of the United States, including wetlands. The Section 404 regulatory pennit program is administered jointly by the EPA and the U.S. Army Corps of Engineers (Corps). The Corps issues the actual permit. Whereas the Section 404 pennit applies to waters of the United States, the Corps also issues Section 9 and Section 10 pennits under the Rivers and Harbors Act for activities applying to navigable waters of the United States.
The Corps Section 404 pennit and the Section 9 and Section 10 per- mits review includes significant consideration of environmental im- pacts; among those are conservation, economics, aesthetics, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shore erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, and considerations of proper- tyownership.
The Environmental Protection Agency has issued Section 404(b)(1) guidelines that prohibit discharge of dredged or fill material 1. Ifthere is a practicable alternative with less adverse impact on the aquatic environment unless the alternative poses other significant environmental problems
2. If the discharge will have an unacceptable adverse impact, whether individually or cumulatively, on the aquatic ecosystem
3. If the discharge will violate state water quality standards, violate toxic effluent standards, jeopardize a species listed as threatened or endangered under the Endangered Species Act, or violate any requirement of a marine sanctuary designated under the Marine Protection, Research, and Sanctuaries Act
4. Unless appropriate and practicable steps have been taken which will minimize potential adverse impacts of the discharge on the aquatic ecosystem
These are the four basic restrictions to permitting discharge of fill or dredged material. The guidelines require identification of all di- rect, indirect, secondary, and cumulative impacts which could result from a proposed discharge. All practicable steps must be taken to minimize the adverse impacts, including providing compensation (for example, wetland restoration and creation) for unavoidable impacts.
The Section 404(b)(1) guidelines (40 CFR Part 230) offer extensive and valuable information and methodologies to the environmental an- alyst for evaluation of potential environmental effects on water re- sources and aquatic ecosystems. The guidelines require factual determinations, in writing, of the potential short-term or long-term effects of a proposed discharge of dredged or fill material on the phys- ical, chemical, and biological components of the aquatic environment. Determinations must be made regarding
• Physical substrate
• Water circulation, fluctuation, and salinity
• Suspended particulates and turbidity
• Contaminants
• Aquatic ecosystems and organisms
• Disposal sites
• Cumulative effects on the aquatic ecosystem
• Secondary effects on the aquatic ecosystem
Specific guidelines are given to assist in making the required factu- al determinations. Figure 18.3 lists the areas of possible impact that are discussed. The next step in adherence to the Section 404(b)(1) guidelines is to make findings of compliance or noncompliance with the four restrictions noted above. Three findings are possible: 0) com- plying, (2) complying with inclusion of appropriate and practicable discharge conditions to minimize pollution or adverse effects on the affected aquatic ecosystems, or (3) not complying.
Section 404 permits are issued in two basic forms: individual permits and general permits. Individual permits are project-specific and are is- sued after a case-by-case review of individual permit applications. General permits authorize categories of activities in specific geographic regions or nationwide. If an activity is covered by a general permit, an application for a permit is not required. The general permits are issued when (1) proposed activities are substantially similar in nat~re and cause only minimal individual and cumulative environmental impacts; or (2) the general permit would result in avoiding unnecessary duplica- tion of regulatory authority exercised by another agency. Based on the above, there are three types of general permits: regional, nationwide, and programmatic. An activity is authorized under general permits only if that activity and the permittee satisfy all the general pennit's terms and conditions. Details of the Nationwide Pennit Program are contained in 33 CFR Part 330.
The Section 404 process has a 30- to 45-day required public review and comment period. It is advantageous to integrate the Section 404 review process with the NEPA review process of the Environmental Assessment or Draft Environmental Impact Statement. Specific re- quired details for actual permit application will most likely not be available at the draft environmental document stage, because numer- ous alternatives are being considered. The draft document should, however, note the location of proposed dredge and fill activities, the potential adverse effects, and proposed mitigation measures for each alternative. Documentation of coordination with the Corps and appro- priate federal, state, and local resource agencies should be included. The final environmental document should identify, for the selected al- ternative, the location of permitting activities, quantities of dredge and fill material, potential impacts, and mitigation measures. Any outstanding unresolved issues should be identified.
The actual application for a Section 404 permit will likely be made after the final environmental document because of the need for detailed final design information. Some agencies may choose, however, to com- plete the pennit at an earlier stage. In many cases, Section 404 pennits may apply to projects or actions that are not "major federal actions" and therefore would not require an Environmental Impact Statement.
A Corps decision on a permit application requires either an Environmental Assessment or an Environmental Impact Statement, unless it is included within a categorical exclusion. If another federal agency is the lead agency for an action, the Corps will most often be- come a cooperating agency for the environmental document.
18.5 Marine Environment
Actions or projects that may affect marine resources will require an analysis of potential physical, chemical, and biological impacts. Such projects may include sewage treatment plants or industries with dis- charges into the ocean; offshore drilling projects; harbor develop- ments or improvements; changes in shipping operations or type and quantity of activities at an existing port; or construction of bridge or tunnel crossings of bays or estuaries.
The discharge of effiuent into ocean waters requires a Clean Water Act National Pollutant Discharge Elimination System (NPDES) per- mit. The permit establishes discharge limitations for all major waste- water constituents, aquatic life toxicants, noncarcinogens, and carcinogens. The NPDES permit also requires an effluent monitoring program and a receiving water monitoring program. Monitoring programs that may be in place because of NPDES permit requirements are a valuable source of information on the existing physical, chemi- cal, and biological characteristics of the marine environment in an area of a proposed project or action.
Other important sources of information are state, regional, and local agencies and established ocean plans. The U.S. Geological Survey conducts extensive studies and monitoring of many of the na- tion's estuaries, bays, deltas, and marine environments, including water quality, water quantity, and such effects as saltwater intrusion into groundwater supplies. The Department of Commerce, National Marine Fisheries Service, will supply information on threatened and endangered marine species of plants and animals.
The description of the existing marine environment should be given as necessary to determine impacts and resolve issues relevant to the specific project or action being proposed and evaluated. The analyst is warned not to include extraneous data and thereby create an encyclo- pedic narrative just because the information may be interesting to the researcher. If the information and data are not relevant to the magni- tude of potential effects and to the decision at hand, leave them out.
For the purpose of showing the types of infonnation that may be rele- vant, the subjects addressed in an Environmental Impact Statement for a major municipal wastewater treatment facilities plan, with discharges into the Pacific Ocean off the coast of California (County Sanitation Districts ofLos Angeles County 1994), are shown in Fig. 18.4.
Because of the direct and potentially significant impact on marine re- sources, the assessment outlined in Fig. 18.4 included a comprehensive description of existing chemical conditions, aquatic resources, physical characteristics, and historic pollution problems. This degree of thor- oughness is appropriate for municipal or private industrial projects in- volving the disposal of solid wastes or wastewater into ocean waters. It also may be appropriate for navigational dredging operations, port de- velopments, or agriculture-related management programs.
As noted in the outline in Fig. 18.4, impacts associated with effluent discharge include contaminants and suspended solids. Improvements of source control and treatment practices mitigate the potential adverse effect of the effluent. This particular assessment is further complicated by the existence of an historical sediment deposit contaminated with sulfides, metals, PCBs, and DDT. Persistent contaminants, such as DDT, from the sediment deposit are gradually being transported to the sediment surface and redistributed into the marine environment. This upward migration of contaminated sediments is caused by ocean cur- rents and disturbances by animals. The historically deposited sedi- ments have been partially buried by recent sediments from the wastewater outfall. Increasing treatment standards at the plants will reduce the release of suspended solids, normally considered an environ- mentally positive effect. If, however, that reduction in solids slows the burial of the historically contaminated sediment, the impact may, in fact, be adverse. This example demonstrates the sometimes extremely complicated nature of environmental impact assessment studies.
Runoff from agricultural land use is a major source of pollution within many of the nation's estuaries and bays. An example is the Susquehanna River's contribution of nitrogen and phosphorus ("nutri- ents") to the Chesapeake Bay. Nutrients nourish algal blooms that de- prive the Bay's grasses of sunlight and deplete water of oxygen. Draining some of the most productive agricultural lands in the na- tion, the Susquehanna River transports mass quantities of nitrogen from fertilizer and animal waste to the Bay. Pollution reduction strategies in this case include statewide bans on detergents with phosphorus; control of runoff from urban areas, farmland, and pas- tures; improvements in sewage treatment; and preservation of forest and wetlands, which act as buffers to nutrient pollution inputs (U.S. Department of Interior, USGS 1995k).
Section 103 of the Marine Protection, Research, and Sanctuaries Act of 1972 applies to the transportation of dredged material for pur- pose of disposal in the ocean. Under the jurisdiction of the Corps of Engineers, a permit is required to determine that "the disposal will not unreasonably degrade or endanger human health, welfare, or amenities, or the marine environment, ecological systems, or econom- ic potentialities." As with a Section 404 permit, the Environmental Protection Agency has the authority to deny the use of any defined areas as a disposal site if that will produce an unacceptable adverse effect on municipal water supplies, shellfish beds and fishery areas, wildlife, or recreational areas.
The Rivers and Harbors Act of 1899 regulates the construction of dikes, dams, bridges, and causeways across navigable waters of the United States (Sections 9 and 10); establishes harbor lines (Section 11); and grants permission for use of sea walls, bulkheads, jetties, dike, levee, wharf, pier, or other work built by the United States (Section 14). Coastal zones and barriers are discussed in the next chapter.
18.6 Summary of Water-Related Permits-and Legislation
Permits and legislation discussed in this chapter that normally may apply to evaluation of water resources impacts are summarized in Fig. 18.5 a and h.
Marriott, B. (1997). Environmental impact assessment: A practical guide. New York, NY: McGraw-Hill.
5ummsryof Form AD-1006
PART I -- Project Information (location, name,etc.)
; "
Figure 16.1
PART II -- Indlcate6 If FPPA farmland exi6t6 on the prop06ed 6ite ana how many aCr'e6, major crop6, etc.
PART III -- Total acre6 of lana to be dl6turbed ~ the project
PART IV -- Calculatee percentage on 61te ba5ea on total FPPA farmland in region or County
PART V -- Land evaluation criterion, relative value, from 1to 100 pointe
PART VI -- Site a%e66ment criteria, maximum 160 polnt6
PART VII -- Aade tne polnt6 for the two type6 o f criteria, maximum possible 260 point6
