In 2020, the Central Valley Regional Water Quality Control Board will begin implementing strict new requirements for the discharge of nitrate and salt from agriculture. After more than a decade in development, the CV-Salts Basin Plan Amendment will make two important changes to all Waste Discharge Requirements (WDR’s) under which all surface and groundwater discharges fall. Here is a link to a comprehensive summary of the changes and helpful maps.
Nitrate discharges that contribute to an exceedance of water quality standards will need to be significantly reduced and residence whose water exceeds the standards will need to have their water supply replaced. The Regional Board has adopted a prioritized approach with Priority 1 basins found largely in the San Joaquin Valley. Ag in those areas, will need to join regional management zones to plan and fund replacement drinking water. Priority 2 areas, which include Yolo County, will follow the same path in the next 3-5 years.
Salinity discharges will also face additional regulatory burdens. Ag and other dischargers will need to participate in a 10-year study to evaluate salt loading and develop plans to significantly reduce impact on ground and surface water. In the alternate, discharges will need to prove that they do not exceed salinity standards as a result of their operations, a very difficult standard for irrigated agriculture.
What this means for rice
The good news is the impact on rice should be narrow. The anaerobic nature of rice production limits the conversion of fertilizer to nitrate and water does not move well through our heavy clay soils. As discussions convene in the Priority 2 area in Yolo County, we will work with the Sac Valley Water Quality Coalition and other dischargers to educate them on rice and understand proposed replacement water solutions. For salinity, we will participate in the 10-year study to help craft the long term solution.
What this means for the Sacramento Valley
If you grow crops other than rice in the Sacramento Valley, you will need to be on the lookout for the development of Best Management Practices (BMP’s) to reduce nitrate loading. Also pay close attention to changes in projected degradation of water quality over the next 20 years and where you farm. Finally, the Sac Valley Coalition is still evaluating its approach to addressing salinity.