HW-14

CENE 599 Rural Water Wastewater

Spring 2016

Homework #6

Page 1 of 2

Assigned: Wednesday 23 March

Due: Monday 4 April

Problem 1. Septic System Design. Design a septic system using Coconino County guidelines for the

single family homes shown below. Use the percolation test data shown on the figure below for Lot 138.

In the design of the distribution system you can use any of the three methods that we reviewed in class.

Problem 2. Anaerobic Lagoon Design. Design an anaerobic pond for a tropical setting (Temperature >

22oC) on a volumetric loading rate basis using World Health Organization (1987) criteria and the data

provided below. Design for two ponds operating in parallel, either circular or square (L=W), with vertical

walls.

Problem 3. Facultative Lagoon Design. Design a facultative pond system with two ponds in series, using

the same design data as in Problem 2. Design on an areal loading basis using an organic loading rate of

90 kg/ha/d, a depth of 2.0 meters, and L:W=3.0.

Graduate Students: Problem 4. Using the same data as in Problem 3, design the facultative pond using

the Wehner-Wilhelm approach.

Data for Problems 2, 3, and 4:

Design flow rate = 1,200 m3/day

Influent BOD5 = 400 mg/L

Effluent BOD5 = 50 mg/L

Sewered Population = 7,600 people

Maximum Bottom Temperature in Local Waters = 20 oC

Temperature of Pond Water at Bottom of Pond = 10 oC

CENE 599 Rural Water Wastewater

Spring 2016

Homework #6

Page 2 of 2

House Floor Plan for Problem 1:

Percolation Test Data for Problem 1: