Conway

McGrath Lake is polluted. The Los Angeles Regional Water Quality Control Board (Regional Board) has established the total maximum daily load (TMDL) of pollutants allowed in the lake. Owners of private property within which a portion of the lake is located will likely be held responsible for remediation of the pollution. They contend the TMDL may not be stated in terms of concentration of pollutants in lake bed sediment. The trial court denied their petition for a writ of mandate. We affirm. The lake is its water and its sediment.

FACTS

BACKGROUND

McGrath Lake, situated at the southern end of McGrath State Beach park, has about 12 acres of surface area. It is located in the McGrath Lake subwatershed. The subwatershed is approximately 1,200 acres consisting primarily of agricultural fields, petroleum facilities, park land, public roads and a closed landfill. The primary activity in the subwatershed is agriculture. McGrath Lake receives runoff from the agricultural lands. Much of the runoff reaches the lake by a ditch known as the “Central Ditch.” The lake is a terminal lake; that is, it has no natural outlet. McGrath Lake, including its lake bed sediment, is polluted…