Santa Maria Watershed TMDL - Nutrients


Problem Statement - Many surface waterbodies in the lower Santa Maria River and Oso Flaco Lake watersheds are impaired due to exceedances of water quality criteria for nitrate, unionized ammonia, and associated nutrient-related problems such as excessive orthophosphate, dissolved oxygen imbalances, toxicity, and excess algal biomass.  As a result, a wide range of current or potential designated beneficial uses – including aquatic habitat, drinking water supply, groundwater recharge, and agricultural supply - are not being supported in these waterbodies, and therefore these impairments constitute a serious water quality problem.  This project identifies the water quality impairments and describes a plan to achieve water quality objectives and ultimately restore the designated beneficial uses of surface waters.



Status and Public Notices

Approval status

  • Central Coast Water Board
    - adopted May 30, 2013.
  • State Water Resources Control Board
    - approved February 4, 2014.
  • Office of Administrative Law
    - approved May 22, 2014, which is the effective date.
  • US Environmental Protection Agency
    - approved March 8, 2016.