A

A lake in New Jersey has a surface area of 12 acres, water depth of 8 ft, and water detention time of 40 days. (The water detention time is equal to the volume of water divided by the rate of water flow.) The lake watershed consists of 170 acres of forest and 340 acres of residential area. Volume of the unconsolidated bottom sediment was measured to be 9,000 cubic yards. Rate of the bottom phosphorous release was measured to be 2.6 g/m2/yr. Assume rates of phosphorus loading from the watershed are 0.1 lb/acre/yr for forest and 1.0 lb/acre/yr for residential area, respectively. Assume no losses of phosphorus from reaction and settling. Estimate phosphorous concentration of the lake water. If the lake phosphorus concentration exceeds the lake water quality criterion of 0.05 mg/L, evaluate the effectiveness of two water-environment restoration approaches, separately or combined together: (1) dredging/removal of the lake bottom sediment and (2) stormwater BMPs for the residential area with 60% phosphorus removal efficiency.

Texted answers only No photos