Wastewater

Treatment Requirements

 

Wastewater discharges at Rancho Murieta are controlled by the California Regional Water Quality Control Board, Central Valley Region.

Recycling of the treated wastewater takes place on the golf courses. Reclaimed water used for the irrigation of parks, playgrounds, schoolyards, and the golf course, must meet the requirements of Title 22, Division 4 of the California Code which require an adequately oxidized, coagulated, clarified, filtered, and disinfected wastewater, the standard our reclaimed water meets.

Treatment Process Overview
Because a substantial amount of land was available within the development, a system utilizing a series of aerobic/anaerobic ponds was selected. This type of system provides the required treatment at a low operating cost to the District. The ponds are followed by a tertiary treatment process, which meets the more extensive reuse standards of Title 22.

The treatment process utilized at Rancho Murieta is unique in that it utilizes a number of basic and proven processes to produce a very high quality effluent.

Wastewater is received at the treatment plant from three major pumping stations and flows successively through five ponds. Wastewater is treated in the ponds naturally through bacteriological action supplemented with mechanical aeration. The pond effluent is stored in two large reservoirs. Within these reservoirs additional natural treatment occurs. These reservoirs allow storage of the secondary treated wastewater until the need arises for irrigation of the golf course. When this occurs, generally in April, stored secondary effluent is further treated in the tertiary plant. It is operated until the supply from the reservoirs is exhausted or the irrigation season ends, about the middle of October.

The tertiary plant utilizes the Dissolved Air Floatation process, followed by filtration. These processes remove algae and fine solids contained in the secondary effluent. The effluent from the filter is discharged to the chlorination contact chamber for disinfection.

Disinfected wastewater enters an equalization basin. It serves as a flow equalizer, as the demand from the golf course varies throughout the day, while it is most desirable to maintain a fixed flow through the tertiary process.