Task Force Monitors Salinity in Water

In 2004, wastewater treatment plant operators and water districts in the Santa Ana Watershed, including the Orange County Water District, joined with the Santa Ana Regional Water Quality Control Board to form the Santa Ana Watershed Basin Monitoring Program Task Force (Task Force). This group meets on a regular basis to monitor salt levels (salinity) in surface water and groundwater basins in the watershed and assists the agencies in complying with the regulations that manage salinity in discharges to waterbodies like the Santa Ana River.

Typical methods used to manage salt levels include desalinating brackish groundwater, improving wastewater treatment, and recharging groundwater basins with lower salinity supplies. On-going drought conditions have made it more difficult to manage salinity. Without significant precipitation, surface waters are not sufficiently diluted by rainwater, which results in rising total dissolved solids (TDS) in surface waters. The Task Force recently joined in an effort with the Southern California Salinity Coalition to study this issue and propose solutions to this challenge.

Increasing salinity in water supplies is a significant problem in Southern California. One measure of salinity in water supplies is the amount of TDS. TDS is related to the hardness or softness of water; hard water causes soap scum and scale build-up in appliances and plumbing. Elevated TDS can contaminate groundwater supplies, constrain implementation of water recycling projects and cause other negative economic impacts such as the need for increased water treatment. One major source of TDS in water supplies is runoff from agricultural and urban areas into creeks and rivers.

Removing TDS from water supplies is difficult and expensive; preventing salt build-up is much preferred. For Orange County, one important preventative measure is to maintain high quality water in the Santa Ana River. The river is one of the main sources of water that replenishes the Orange County Groundwater Basin. Continuing cooperative efforts, such as being undertaken by the Task Force, are essential for maintaining high quality water supplies in the Santa Ana Watershed.