Wastewater Rates

Non-Residential Customers

Commercial, industrial, and institutional (CII) customers are charged variable rates based on cost of service and billed bimonthly. The rates have two components: collection through the sanitary sewer system and treatment/disposal at the wastewater treatment facility. The collection rate is based on volume only, while the treatment rate is based on volume and wastewater strength.

Wastewater strength is measured by the degree of organic pollutant known as biological oxygen demand and total suspended solids. Rates are higher for customers with a higher level of organic pollutant because it costs more to treat. Rates are also higher for customers with higher flow and volume.

Please contact Customer Service via email or at 925-828-8524 if you have questions about the strength factor that applies to your business.

Commercial / Institutional / Industrial

Notes:

• Wastewater Strength: Strength is an average of biochemical oxygen demand (BOD) and total suspended solids (TSS), measured in milligrams per liter (mg/L)
• Billing Unit: List of example business types that fall within the strength category; this is not a full list of business types for each strength category
• Billing Unit: One cubic hundred foot (ccf) equals 748 gallons

Wastewater Strength	Business Types	Billing Unit	Rates Effective July 1, 2025
Less than or equal to 300 mg/L		ccf	$4.90
Between 300 and 450 mg/L	Hotels/Motels with Dining Facilities, Fast Food Restaurants, School with Cafeteria	ccf	$5.87
Between 450 and 600 mg/L	Banquet facilities, Cafeteria, Full Service Restaurant	ccf	$6.83
Between 600 and 750 mg/L		ccf	$7.80
Between 750 and 900 mg/L	Bakeries, Donut Shops, Ice Cream Shops, Markets with Food, Mortuaries	ccf	$8.76
Between 900 and 1,050 mg/L	Car Washes with Steam Cleaning	ccf	$9.72
Greater than 1,050 mg/L		ccf	TBD by District

Pretreatment Program

In addition to the service charges listed above, customers participating in the District’s Industrial Pretreatment Program pay fees(PDF, 135KB) that reflect the DSRSD staff effort involved in permitting, monitoring, and lab analyses. All industrial customers complete an Industrial Waste Discharge Permit Application to determine whether they are required to participate in the program. Contact the Senior Environmental Compliance Inspector at 925-875-2335 regarding industrial wastewater rates, the Pretreatment Program, or the permit.

Rate Changes

The District bases its wastewater rates on the cost of providing service to each class of customer and rates usually increase each year on July 1. The DSRSD Board of Directors may change rates at other times as a result of rate studies or other factors. Customers are notified when rate changes are proposed as required by Proposition 218. Customers are encouraged to attend public hearings regarding rate changes and submit written comments. For more information on your rights to protest rate changes, see:

• League of California Cities Proposition 218 Implementation Guide (pg. 66)
• California Legislative Analyst’s Office: Understanding Proposition 218

Frequently Asked Questions