How Rates are Calculated

How Rates are Calculated

The MSD bill you receive each month contains a Wastewater User charge.

Wastewater User Charge (WW USER CHG)

This charge covers MSD’s costs for collecting and treating the “used” water that gets disposed of in your sinks, toilets and floor drains. This water travels through miles of pipes to one of our seven treatment plants, where it is treated to high standards before safely returning to our region’s waterways.

Your Wastewater User Charge includes a base charge and a volume charge. All customers pay the same base charge. The volume charge varies, depending on how much water you use.

Because sewer flows are not metered, MSD must estimate how much wastewater your home produces. The volume charge is determined one of two ways: residential customers with and without water meters.

View rate information for commercial and industrial customers below.

Commercial / Industrial Customers

Unit of Measurement Rate
Base Charge $26.35/mo.
Metered Volume $4.87/hundred cubic feet (CCF)
Compliance Charge Tier 1: 0 Inspection / 0 Sample Point $3.14/mo.
Tier 2: 1 Inspection / 0 Sample Point $62.61/mo.
Tier 3: 1 Inspection / 1 Sample Point $137.75/mo.
Tier 4: 1 Inspection / 2 Sample Points $203.49/mo.
Tier 5: 1 Inspection / More than 2 Sample Points $266.10/mo.

Surcharges for Excess-Strength Sewage

Unit of Measurement Rate
Suspended solids over 300 mg/liter $283.87/ton
Biodegradable oxygen demand over 300 mg/liter $708.56/ton
Chemical oxygen demand over 600 mg/liter $354.30/ton

Note: These surcharges apply to sewage from commercial / industrial customers, which is heavily laden with pollutants above the normal domestic strength and requires extra wastewater treatment.