Final Exam Es470 Spring 2005.

 

1. Explain what each component of a wastewater treatment plant is and what it does to have an impact on the final quality level of water discharged to the Rio Grande.

 

 

 

 

 

2. Two homeowners have 3/4 of an ac of land in the north valley in Las Cruces NM. One owner has a sand loam soil and the other owner has a clay soil . The home owners also have a problem with flees on their dogs. They treats the dogs and then sprays the yard area with diazinon to control the flees. What is the impact on the environment and ground water. Run CMLS and capture the screen to answer the question. Explain what the half-life and partitioning coefficient is for diazinon and how these chemical parameters affect the movement of the chemical.

 

 

3. Explain the permitting requirement for selecting a new Solid Waste Landfill . Explain all the information needed by the permit application and the process that a city and county must undergo to decide if they need a new solid waste land fill and if so where it should be placed.

 

 

 

 

4. The city of Las Cruces New Mexico is trying to find a new location to apply sewage sludge because the current disposal system of drying the material and putting it in a land fill is too expensive. The Forman at the wastewater treatment plant stated that the sewage sludge distribution truck applies 4000 gal a load and thirty loads a day must be applied to the land. At the best possible location, the depth to the water table is three hundred feet and the soil a loam soil.

How many acres should the city say they are going to use for the land application in the requested permit to EPA and how long should they apply for the permit to keep the wetting front above 150 ft.  What is the average moisture content in the soil profile to transmit the sewage sludge for your design?

The minimum time they want a permit for is 10 years.

 

 

 

5. The discharge into the drain system at Elephant Butt irrigation system for one stead state flow event is 5 ft^3/sec ( 0.141 m^/sec) and the drain is 10 miles long (16093 m). The drain acts as a wetlands and is 30 ft (9.1m) wide at its base and runs 2 ft (0.61) deep. The input concentration of total suspended solids is 250 mg/l When the drain discharges into the Rio Grande River what is the concentration and is it lower than the average concentration in the river . area 146446 m^2 See

http://nm.water.usgs.gov/publications/abstracts/wrir02-4224.pdf#search='total%20suspended%20solids%20in%20the%20rio%20grande'

 

 

 

 

 

 

 

 

6. Explain how wind speed, wind direction, and the Paasquill weather stability factor affect the dispersion of pesticides into the atmosphere. How do you calculate the concentration of pesticide 100 ft down wind from the field that it was applied to knowing the pesticide application rate and the volatilization rate coefficient for the pesticide.