All orders adopted by the Board are precedential with the exception of those that specifically state the contrary. Orders signed by an individual, for example by the Executive Director, are not precedential and are denoted by an asterisk (*).

Precedential orders provide guidance for later decisions and orders. The Board and the nine Regional Water Quality Control Boards (Regional Boards) ordinarily will follow State Board precedents, or provide a reasoned analysis for not doing so. Administrative precedents do not have the same binding effect as statutes or administrative regulations, however. The Board may refine, reformulate or even reverse its precedents on a case-by-case basis in light of new insights or changed circumstances. A Regional Board cannot reverse a State Board precedent, but a Regional Board may distinguish a State Board precedent. A Regional Board may conclude that based on differences between the facts before the Regional Board and the facts that were the basis for the State Board precedent, a State Board precedent either does not apply or should be modified as applied in the proceeding before the Regional Board.