Minnesota Administrative Rules
Agency 167 - Pollution Control Agency
Chapter 7081 - MIDSIZED SUBSURFACE SEWAGE TREATMENT SYSTEMS
Part 7081.0130 - FLOW AND WASTE CONCENTRATION DETERMINATION FOR OTHER ESTABLISHMENTS

Universal Citation: MN Rules 7081.0130

Current through Register Vol. 49, No. 13, September 23, 2024

Subpart 1. Method.

Design fows for other establishments are determined by methods in items A to C. Measured fow values must be used for design fows when they are higher than the estimated fow values from table I.

A. The design fow of sewage for SSTS serving other establishments is estimated using table I.

TABLE I

ESTIMATED DESIGN SEWAGE FLOW FROM OTHER ESTABLISHMENTS

(1) Dwelling units (also see outdoor recreation) Unit Design fow (gal/ day/unit)
(a) Hotel or luxury hotel guest 55
square foot 0.28
(b) Motel guest 38
square foot 0.33
(c) Rooming house resident 45
add for each nonresident meal 3.3
(d) Daycare (no meals) child 19
(e) Daycare (with meals) child 23
(f) Dormitory person 43
(g) Labor camp person 18
(h) Labor camp, semipermanent employee 50
(2) Commercial/Industrial
(a) Retail store square foot 0.13
customer 3.8
toilet 590
(2) Commercial/Industrial
(b) Shopping center employee 11.5
square foot 0.15
parking space 2.5
(c) Ofce employee/8-hour shift 18
square foot 0.18
(d) Medical ofce* square foot 1.1
practitioner 275
patient 8
(e) Industrial building* employee/8-hour shift 17.5
employee/8-hour shift with showers 25
(f) Laundromat machine 635
load 52.5
square foot 2.6
(g) Barber shop* chair 68
(h) Beauty salon* station 285
(i) Flea market nonfood vendor/space 15
limited food vendor/space 25
with food vendor/space 50
(3) Eating and drinking establishments
(a) Restaurant (does not include bar or lounge) meal without alcoholic drinks 3.5
meal with alcoholic drinks 8
seat (open 16 hours or less) 30
seat (open more than 16 hours) 50
seat (open 16 hours or less, single service articles) 20
seat (open more than 16 hours, single service 35
articles)
(b) Restaurant (short order) customer 7
(c) Restaurant (drive-in) car space 30
(d) Restaurant (carry out, including caterers) square foot 0.5
(e) Institutional meals meal 5.0
(f) Food outlet square foot 0.2
(g) Dining hall meal 8.5
(h) Cofee shop customer 7
(i) Cafeteria customer 2.5
(j) Bar or lounge (no meals) customer 4.5
seat 36
(4) Entertainment establishments
(a) Drive-in theater car stall 5
(b) Theater/auditorium seat 4.5
(c) Bowling alley alley 185
(d) Country club member (no meals) 22
member (with meals and showers) 118
member (resident) 86
(e) Fairground and other similar gatherings visitor 1.5
(f) Stadium seat 5
(g) Dance hall person 6
(h) Health club/gym member 35
(5) Outdoor recreation and related lodging facilities
(a) Campground campsite with sewer hook-up (per person) 32
campsite with sewer hook-up (per site/space) 100
campsite without sewer hook-up, with central toilet or shower facility (per site) 50
campsite without sewer hook-up, with central toilet or shower facility, served by central dump station (per site) 63
(b) Permanent mobile home mobile home 225
(c) Camp, day without meals person 20
(d) Camp, day with meals person 25
(e) Camp, day and night with meals person 45
(f) Resort/lodge hotel person 62
(g) Cabin, resort person 50
(h) Retail resort store customer 4
(i) Park or swimming pool guest 10
(j) Visitor center visitor 13
(6) Transportation
(a) Gas station/convenience store customer 3.5
(b) Service station* customer 11
service bay 50
toilet 250
square foot 0.25
(c) Car wash* (does not include car wash water) square foot 5
(d) Airport, bus station, rail depot passenger 5
square foot 5
restroom 565
(7) Institutional
(a) Hospital* bed 220
(b) Mental health hospital* bed 147
(c) Prison or jail inmate 140
(d) Nursing home, other adult congregate living resident 125
(e) Other public institution person 105
(f) School (no gym, no cafeteria, and no showers) student 14
(g) School (with cafeteria, no gym and no showers) student 18
(h) School (with cafeteria, gym, and showers) student 27.5
(i) School (boarding) student 95
(j) Church seat 4
add for each meal prepared 5
(k) Assembly hall seat 4
(8) Miscellaneous
(a) Public lavatory user 5
(b) Public shower shower taken 11

* Waste other than sewage is only allowed to be discharged into the system if the waste is suitable to be discharged to groundwater.

(1) Unless otherwise noted in table I, the fow values do not include fows generated by employees. A fow value of 15 gallons per employee per eight-hour shift must be added to the fow amount. Design fow determination for establishments not listed in table I must be determined by the best available information and approved by the local unit of government.

(2) Flow for systems not designed for maximum, seven-day, daily use may be determined by averaging the estimated fow from table I for a consecutive seven-day period if fow equalization is used and approved by the local unit of government.

(3) Maximum daily fow calculated under this item must be used to determine septic tank size according to part 7080.1930.

B. The measured design fow of sewage for SSTS serving other establishments is the average of the maximum measured daily fows for a consecutive seven-day period. Measurements must be corrected for occupancy or use according to Prescriptive Designs and Design Guidance for Advanced Designers, incorporated by reference under part 7080.1550, subpart 2.

C. SSTS using the fow determination method from part 7081.0040, subpart 1a, item B, subitem (1), may expand based on those measurements according to the following:
(1) measured fow values may be used only for similar units;

(2) expansion above 25 percent of the total fow is not allowed unless the fow is remeasured or estimated values from table I are used; and

(3) measured fow values may not be used at any other facility or property.

Subp. 2. Waste concentration.

If concentrations from the sewage tank to the soil dispersal system are expected to be higher than 170 mg/l BOD (or 125 mg/l CBOD5), 60 mg/l TSS, or 25 mg/l of oil and grease, an estimated or measured average concentration must be determined and be acceptable to the local unit of government. System design must account for concentrations of these constituents so as not to cause internal system malfunction, such as, but not limited to, clogging of pipes, orifices, treatment devices, or media.

Statutory Authority: MS s 115.03; 115.55

Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.