Find Your Watershed

ArcGIS watershed layer by Sonoma Land Trust.

Austin Creek | Green Valley Creek | Laguna de Santa Rosa | Mark West Creek | Petaluma River | Salmon Creek

Good Practices for Water Pollution Prevention

For Your Household
Examples of good practices: limit paved surfaces; landscape with nature, irrigate during cooler hours of the day, limit fertilizer applications on lawns and gardens; proper septic system management; proper chemical use, storage, and disposal. Chemicals and oil should not be poured into sewers, where they can result in major water quality problems.

For Agriculture
Farmers can reduce water pollution by managing sedimentation through erosion control measures; managing nutrient use, and saving money through reduced use of fertilizers; reducing confined animal facility wastewater through waste management; managing irrigation by improving water use efficiency; managing pesticides through Integrated Pest Management (IPM); and managing livestock grazing to prevent overgrazing.

Tertiary Treated Wastewater

Here is some information on types of wastewater treatment:

Primary Treatment – removes insoluble matter; Method: Gravity separation
Secondary Treatment – removes biological impurities; Method: Microorganisms used to rid water of 95% of organic materials
Tertiary Treatment – removes nutrients, heavy metals and chemical contaminants; Method: Microfiltered through coal/sand/gravel and Chlorine* disinfection (same treatment as drinking water)
* Chlorination will not kill some parasitic cysts, so must it be used in combination with filtration.

According to Monterey Regional Water Pollution Control Agency’s 1987 study, no pathogen problems have arisen in crops grown with Tertiary Wastewater; it is the same as well water.

Organic Farming with Tertiary Wastewater
Federal Standards for “Organic” foods do not address recycled water, so by default organic farmers may use tertiary water. However, in 2000 California Certified Organic Farmers decided that recycled water can only be applied to non-edible food parts. For example, drip irrigation of strawberries and lettuce is OK, but not sprinkler application.

According to the Water Reuse Association (, secondary wastewater may be used on food crops if they go to animal fodder, or it undergoes commercial pathogen-destroying processes. Tertiary water may be used anywhere, including all food crops, schools, playgrounds, etc. 1998 Assembly Bill AB237 Title 22 addresses water reuse regulations.

Facts on the Santa Rosa Subregional Reclamation System, From the California State Water Resources Control Board: Municipal Wastewater Reclamation Survey:
Local processing methods include: Activated Sludge (including oxidation ditches), Coagulation and Flocculation, Filtration, Chlorination and Dechlorination.
Capacity: 18 million gallons/day
Flow: 17.x million gallons/day
Water Users: Farms, schools, golf courses, vegetable irrigation, vineyards, pasture, fodder, Sonoma State University landscaping, Rohnert Park parks
* There is significant unplanned indirect reuse of effluent due to percolation into streambeds and groundwater supplies in some communities.

Most important things to remember/watch out for:
* The cleanliness of treated wastewater depends on the cleanliness of the sewer water constituent. So if landfill leachate, industrial and household chemicals, and pesticides go in, more chemicals and nutrients will be present in treated effluent.
* For the most part, the water is adequately cleaned for pathogens, so public health is protected in that aspect.
* Storm high flows may cause overflow of untreated wastewater release, because the facilities do not have the capacity for high flows.
* Ask your local wastewater plant how it accounts for stable organics and dissolved minerals, nutrients, and chlorinated organics-do they test for them, and what levels do they get?

For more information, contact the CCWI office.