Lab Assignment Dissolved Oxygen in Water Quality

EAS 104 Lab 6: Dissolved Oxygen in Water Quality (17 points)

● Background

Water pollution occurs when harmful waste products, chemicals, and other substances are

introduced into a body of water. Most water pollution can be classified into four main types:

Thermal Pollution, Industrial or Chemical Pollution, Domestic Pollution, and Soil Pollution.

One of the most devastating effects of water pollution on ecosystems is a reduction in the amount

of dissolved oxygen (DO) in a body of water. Fish and other aquatic creatures extract DO from

water as they breathe. As pollution causes the amount of DO to decrease, aquatic animals must

move to cleaner waters or die from suffocation. However, while many species die from lack of

oxygen, there are fish, invertebrates, and microorganisms that thrive in polluted conditions.

Include Your NAME, Class Title (“EAS 104”), Lab Section, and Lab Number (“Lab 6”) for

your assignment title.

1. Why is dissolved oxygen important for a body of water? (1 point)

2. Go to the USGS website, generate a plot of Monthly Water Temperature vs DO concentration

in 2017 using data collected at the site of Passaic River below Pompton River at Two

Bridges NJ (6 points) 1

1. How do water temperature affect the DO level? (1 point)

3. What is the New York safe fishing and bathing standards for dissolved oxygen? (2 points)\

1. Resources: http://www.nyc.gov/html/dep/pdf/hwqs2016.pdf (on page 5)

https://maps.waterdata.usgs.gov/mapper/nwisquery.html?URL=https://waterdata.usgs.gov/nj/nwis/current?1 type=qw&format=sitefile_output&sitefile_output_format=xml&column_name=agency_cd&column_name=site_no&col umn_name=station_nm&column_name=site_tp_cd&column_name=dec_lat_va&column_name=dec_long_va&colum- n_name=agency_use_cd

4. Use information from the tables to answer the following questions:

Table 1- Mean Water Temperature (in degree Celsius) from Hudson River at South Dock at West

Point, NY 2

a. What is the mean water temperature (in degree C) on June 22, 2013 (in Table 1)?

(1 point); convert the temperature to degree Fahrenheit (1 point).

b. Referring to the temperature in part (a), what is the corresponding DO level (mg/

L) from Table 1? (1 point)

c. For the temperature in part (a), what is the 100% oxygen saturation level (in Ta-

ble 2)? (1 point) Hint: round the temperature (from part (a)) to an integer so

that you are able to match the number in Table 2.

Date Mean Water Temperature (degree C) DO (mg/L)

2013-06-21 18.6 8.9

2013-06-22 18.9 8.8

2013-06-23 19.3 8.7

2013-06-24 19.8 8.6

2013-06-25 20.2 8.4

2013-06-26 20.5 8.2

2013-06-27 20.7 8.1

2013-06-28 21.1 8

2013-06-29 21.5 7.9

2013-06-30 21.7 7.8

https://nwis.waterdata.usgs.gov/nwis/dv?2 cb_00010=on&cb_00300=on&format=html&site_no=01374019&referred_module=sw&period=&begin_date=2013-06-01&end_date=2013-06-3 0

Table 2 - 100% Oxygen Saturation at Various Water Temperatures

Water Temperature (degree F) 100% Oxygen Saturation (mg/L)

32 14.6

34 14.2

36 13.9

37 13.5

39 13.2

41 12.8

43 12.5

45 12.2

46 11.9

48 11.6

50 11.3

52 11.1

54 10.8

55 10.6

57 10.4

59 10.2

61 9.9

63 9.7

64 9.5

66 9.3

68 9.2

70 9

72 8.8

73 8.7

d. Calculate the percent saturation value at the water temperature on June 22, 2013.

(1 point) Hint: Percent Saturation Value (%) = [DO level (mg/L) / 100% oxygen

saturation (mg/L)]*100%;

e. Based on your calculation results, what conclusions can be drawn about the water

condition in Hudson River at West Point, NY on June 22, 2013? How did you ar-

rive at your conclusion (referring to Table 3)? (2 points)

Table 3 - Explanation for Percent Saturation Level Findings

75 8.5

77 8.4

Percent Saturation Level

(%)

Explanation

80% - 100% Excellent outlook for most species of fish to survive. Low

bacteria levels. Flies thrive, giving fish plenty of food.

60% - 79% Good outlook for many species of fish to survive, but not all.

Mosquitoes and tubifex worms thrive.

Below 60% Poor outlook for survival for most fish species. High bacteria

levels, microorganisms thrive.