Background

In its review of the East San Joaquin General Order, the State Water Resources Control Board (State Water Board) raised two general questions regarding the East San Joaquin Water Quality Coalition’s (ESJWQC’s) surface water quality monitoring framework:

  • The State Water Board questioned if there was information to support the program’s premise that when the core site and represented sites are similar (i.e., have similar hydrology, crop type, land use, soil type and rainfall, and are assumed to be managed similarly), would the results from a water quality program conducted at a core site be indicative of an exceedance at a represented site?
  • They asked if the core and represented monitoring sites, collectively, are of sufficient spatial density or distribution to be able to reasonably identify exceedances of predetermined limits throughout the watershed.

To assist in answering these questions, the State Water Board directed the Central Valley Regional Water Quality Control Board to convene an expert panel to evaluate the ESJWQC’s existing monitoring and assessment framework, and provide recommendations, if needed.

Incorporated into the Eastern San Joaquin General Order are six questions that the monitoring program must address (Attachment A of the Order):

  • Are receiving waters to which irrigated lands discharge meeting applicable water quality objectives and Basin Plan provisions?
  • Are irrigated agricultural operations causing or contributing to identified water quality problems? If so, what are the specific factors or practices causing or contributing to the identified problems?
  • Are water quality conditions changing over time (e.g., degrading or improving as new management practices are implemented)?
  • Are irrigated agricultural operations of Members in compliance with the provisions of the Order?
  • Are implemented management practices effective in meeting applicable receiving water limitations?
  • Are the applicable surface water quality management plans effective in addressing identified water quality problems?

These six questions were developed during a previous review of the Central Valley’s Irrigated Lands Regulatory Program (ILRP) and associated surface water quality monitoring provisions. These questions have not been challenged and thus are the starting point for the Expert Panel review.

The State’s Nonpoint Source Policy sets forth the general requirement that the monitoring program and the Eastern San Joaquin General Order collectively should include sufficient feedback mechanisms so that the Water Board, dischargers and public can determine if the program is achieving its stated purposes or whether different management practices or other actions are required.