Quantities of Domestic Flow Rates

The following flow rates shall be used for the design of Onsite Wastewater Treatment Systems (OWTS). Any rate determined to be more than 3,000 gallons per day shall be designed, permitted, and inspected in accordance with the requirements of the Missouri Department of Natural Resources (MoDNR).

Establishment Minimum Design Flow Rate (in gallons per day) Design Flow Rate Calculation (in gallons per day)

Residential Facilities

   
Single-Family Residential Dwellings 240 GPD The greater of 120 GPD per bedroom or 60 CPD per occupant
Multi-Family Residential Dwellings (with laundry) 120 GPD 120 GPD per bedroom
Multi-Family Residential Dwellings (without laundry) 100 GPD The greater of 95 GPD per bedroom or 50 GPD per occupant
Mobile Homes 300 GPD 300 GPD per unit

Commercial Facilities

   
Transportation Terminals (including airports, bus stops, railroad stations, etc.) 100 GPD 5 GPD per passenger
Laundromats 580 GPD 580 GPD per machine
Beauty Shops 125 GPD 125 GPD per chair
Bowling Lanes 100 GPD 50 GPD per lane
Businesses (not in table) 100 GPD 25 GPD per employee
Factories without Showers* 100 GPD 25 GPD per person per shift
Factories with Showers* 100 GPD 35 GPD per person per shift
Marinas without Bath Houses 100 GPD 10 GPD per boat slip
Marinas with Bath Houses 100 GPD 30 GPD per boat slip
Hotel/Motel without Cooking Facilities 120 GPD 120 GPD per room
Hotel/Motel with Cooking Facilities 175 GPD 175 GPD per room
Offices 100 GPD 25 GPD per person per shift
Service Stations (<24 hours) 250 GPD 250 GPD per water closet or urinal
Service Stations (24 hour) 325 GPD 325 GPD per water closet
Movie Theater (Seated) 100 GPD 5 GPD per seat
Movie Theater (Drive-In) 100 GPD 15 GPD per vehicle space
Warehouse 100 GPD 30 GPD per employee
Public Park (Toilet Only) 100 GPD 5 GPD per user
Public Park (with Bath House) 100 GPD 15-25 GPD per user

Camps

   
Construction or Work Camps 100 GPD 60 GPD per person
Construction or Work Camps (with Chemical Toilets) 100 GPD 40 GPD per person
Summer Camps 100 GPD 60 GPD per person
Campgrounds with Comfort Stations (no water or sewer hookups) 100 GPD 100 GPD per campsite
Travel Trailer/RV Park (with water and sewer hookups) 120 GPD 120 GPD per space

Assembly and Mercantile

   
Retail Stores 120 GPD 120 GPD per 1,000 sq. ft. of retail sales space
Stadium, Auditorium, Theatre 100 GPD 5 GPD per seat or space
Swimming Pools, Spas and Bath Houses 100 GPD 10 GPD per person
Churches (not including a Kitchen, Food Service Facility, Daycare or Camp) 100 GPD 3 GPD per seat
Churches (including a Kitchen but not Food Service Facility, Daycare or Camp) 100 GPD 5 GPD per seat
Country Club 100 GPD 20 GPD per member

Food and Drink Establishments**

   
Bar (Not Serving Food) 100 GPD 20 GPD per seat
Restaurant (<24 hour) 100 GPD Greater of 40 GPD per seat or 40 GPD per 15 sq. ft. of dining area***
Restaurant (24 hour) 100 GPD 75 GPD per seat***
Food Stand 100 GPD 50 GPD per 100 sq. ft. of area plus 25 GPD per employee***
Other Food Service Facilities 100 GPD 5 GPD per meal***
Meat Market 100 GPD 50 GPD per 100 sq. ft. of area plus 25 GPD per employee***

Institutional**

   
Hospitals 300 GPD 300 GPD per bed***
Daycare Facilities 100 GPD 15 GPD per person
Residential Care Facilities 100 GPD 60 GPD per person***
Rest Homes and Nursing Homes (with Laundry Facilities) 120 GPD 120 GPD per bed***
Rest Homes and Nursing Homes (without Laundry Facilities) 100 GPD 60 GPD per bed***
Day Schools (with Cafeteria, Gym and Showers) 100 GPD 15 GPD per student***
Day Schools (with Cafeteria only) 100 GPD 12 GPD per student***
Day Schools (without Cafeteria or Showers) 100 GPD 10 GPD per student
Boarding Schools 100 GPD 60 GPD per student

*Factories producing industrial waste are regulated by the Missouri Department of Natural Resources (MoDNR).
**Establishments processing food may be required to provide grease interceptors in an accessible location prior to the OWTS.
***Food service operation facilities shall have flows multiplied by 1.5 times to accommodate the high organic strength of the waste. (This multiplier is not used to determine jurisdiction related to the 3,000 gallons flow rate.)