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Treatment component/ sequence category Product performance requirements
Category A: Treatment system performance testing levels
Designed to treat sewage with strength typical of a residential source when septic tank effluent is anticipated to be equal to or less than treatment level C.
Level Parameters
CBOD5 TSS O&G FC Nutrient
(mg/l) (mg/l) (mg/l) (#/100ml) (mg/l)
A 15 15 -- 1,000 --
A-2 15 15 -- -- --
B 25 30 -- 10,000 --
B-2 25 30 -- -- --
C 125* 60 25 -- --
TN -- -- -- -- <20, or actual value
TP -- -- -- -- <5, or actual value

* BOD5 = 170 mg/l

Values for levels A, A-2, B, and B-2 are 30-day values (averages for CBOD5, TSS, and geometric mean for FC). All 30-day averages throughout the test period must meet these values in order to be registered at these levels. Values for levels C, TN, and TP are derived from full test averages.
Category B: All of the following requirements must be met:
Designed to treat high-strength sewage when septic tank effluent is anticipated to be greater than treatment level C, including restaurants, grocery stores, mini-marts, group homes, medical clinics, residences, etc. (1) all full test averages must meet level C; and
(2) the treatment capacity of the product tested in pounds per day for CBOD5 must be reported.
Total nitrogen and phosphorus reduction in Categories A and B Test results must establish product performance effluent quality meeting levels TN and TP, when presented as the full test average.

Statutory Authority:

MS s 115.03; 115.55


32 SR 1420; 35 SR 1353

Published Electronically:

August 29, 2013

Official Publication of the State of Minnesota
Revisor of Statutes