This Pittman Bypass Pipeline separates wastewater discharge from highly saline soils by diverting industrial return flow from an open, unlined ditch. This has reduced groundwater flow and consequent pickup of salts leached from the soil, resulting in an estimated decline in salt loading to the Colorado River of 3,800 tons per year. A monitoring system to establish an accurate record of conditions prior to project operation. A subsurface barrier, an intake pumping plant, a brine reject pipeline, and evaporation ponds was also planned. Other phases were found to be not cost effective.
Reclamation continues to monitor once a year.
Early explorers moved up Las Vegas Wash toward an oasis of spring-fed meadows at the present site of Las Vegas. After the Mormons settled in the 1850's, cattle ranches occupied much of the valley and artesian springs were used to cultivate crops of hay. Surface water was no longer flowing by the late 1940's and few springs in Las Vegas Valley are now active. However, rapid municipal growth has also resulted in a continuous increase in waste water processed through sewage treatment plants and discharged to the lower portions of Las Vegas Wash. Increased urban irrigation along the east side of the valley has resulted in increased ground-water return flows. Rising local concern over the pollution of Lake Mead began in the early 1960's, and Clark County and various political subdivisions took the first steps toward controlling polution in 1964.