Water quality objectives are used by the City of San Diego, water quality professionals, and San Diego Coastkeeper to determine if the analyte measured exceeds the Maximum Contamination Level (MCLs) of surface waters of the San Diego Watersheds.Water Quality Objectives (WQOs) are numerical or narrative limits on constituents or characteristics of water designed to protect designated beneficial uses of the water. California's WQOs are established by the State and Regional Water Boards.
The table below does not list all analytes and is not comprehensive. For more information on the Water Quality Objectives for any watershed in San Diego County, please see the San Diego Regional Water Quality Control Board, San Diego Basin Plan, http://www.swrcb.ca.gov/rwqcb9/programs/basinplan.html.
These objectives are separated into dry weather flow and stormwater flow. Stormwater flow is measured following a storm event with at least a quarter inch of rain within twenty-four hours.
Stormwater Flow
| Analyte |
Water Quality Objective |
Source |
| Ammonia as N (mg/L) |
none |
|
| Diazinon (mg/L) |
0.00008 |
CA Dept. of Fish and Game |
| Fecal Coliform (MPN/100mL) |
20000 |
|
| Nitrate as N (mg/L) |
10 |
Basin Plan |
| Oil and Grease (mg/L) |
15 |
USEPA Multi-Sector General Permit |
| Surfactants/MBAs (mg/L) |
0.5 |
Basin Plan |
| Total Coliform |
none |
|
| Total Phosphorus (mg/L) |
2 |
USEPA Multi-Sector General Permit |
Dry Weather Flow
| Analyte |
Water Quality Objective |
Source |
| Ammonia as N (mg/L) |
1 |
|
| Diazinon (mg/L) |
0.0005 |
CA Dept. of Fish and Game |
| Fecal Coliform (MPN/100mL) |
400 |
|
| Nitrate as N (mg/L) |
10 |
Basin Plan |
| Oil and Grease (mg/L) |
15 |
USEPA Multi-Sector General Permit |
| Surfactants/MBAs (mg/L) |
01 |
Basin Plan |
| Total Coliform |
50000 |
|
| Total Phosphorus (mg/L) |
2 |
USEPA Multi-Sector General Permit |