E. coli (counts1 per 100 mL) |
Geometric Mean2 | Statistical Threshold Value3 |
1. For determining attainment or compliance, counts are considered equivalent to either colony forming units or most probable number. 2. The geometric mean shall not be exceeded in any rolling 90-day period during the recreation season. 2. The statistical threshold value shall not be exceeded more than 10 percent of the time during any rolling 90-day period during the recreation season. |
Note: The department developed the E. coli criteria in this section based on criteria developed by U.S. EPA. U.S. EPA developed the E. coli criteria using membrane filtration methods to count E. coli colony forming units.
Note: Under the department’s beach advisory program, a beach advisory is issued when a beach reaches the “Beach Action Value” of 235 counts per 100 mL and a beach closure is issued at 1000 counts per 100 mL, unless site-specific conditions indicate use of an alternate metric. More information on the beach advisory program is available at http://wibeaches.us. (b) Bacteria site-specific criteria. 1. The department may establish bacteria site-specific criteria by rule to protect a waterbody’s recreational use when it is determined that the statewide E. coli criteria under par. (a) are inappropriate due to site-specific conditions. Once bacteria site-specific criteria are adopted in a rule and approved by U.S. EPA, those criteria supersede the statewide E. coli criteria under par. (a) for that waterbody.
2. Any interested party may submit proposed bacteria site-specific criteria for a waterbody to the department. Any request for bacteria site-specific criteria must include a demonstration that the proposed site-specific criteria were developed using a U.S. EPA approved method, procedure, or test, are based on sound scientific rationale, and are as protective of the recreational use as the statewide E. coli criteria in par. (a). A request for a less-stringent site-specific criteria must also demonstrate that the predominant source of the bacteria is non-human or non-fecal.
Section 5. NR 104.06 (2) (a) (intro.) and (b) (intro.) are amended to read:
NR 104.06 (2) (a) The following surface waters in the southeast district shall meet the standards for fish and aquatic life except that the dissolved oxygen shall not be lowered to less than 2 mg/L at any time, nor shall the membrane filter fecal coliform count exceed 1,000 per 100 ml as a monthly geometric mean based on not less than 5 samples per month nor exceed 2,000 per 100 ml in more than 10% of all samples during any month:
(b) The following surface waters in the southeast district shall meet the standards for fish and aquatic life except that the dissolved oxygen may not be lowered to less than 2 mg/L at any time, nor may the membrane filter fecal coliform count exceed 1,000 per 100 mL as a monthly geometric mean based on not less than 5 samples per month nor may the ambient water temperature exceed 89ºF at any time at the edge of the mixing zones established by the department under s. NR 102.05 (3): Section 6. NR 104.20 (7) is amended to read:
NR 104.20 (7) The sector of Honey Creek above the Clarno-Cadiz town line shall meet the standards for fish and aquatic life except that the dissolved oxygen shall not be lowered to less than 2 mg/L at any time. The membrane filter fecal coliform count in this sector shall not exceed 1,000 per 100 ml as a monthly geometric mean based on not less than 5 samples per month, nor exceed 2,000 per ml in more than 10% of all samples during any month.
Section 7. NR 210.06 (1) (title) and (2) (title) are created to read:
NR 210.06 (1) (title) Disinfection requirements.
(2) (title) Effluent limitations.
Section 8. NR 210.06 (2) (intro.) is amended to read:
NR 210.06 (2) Where and when disinfection is required, the following effluent limitations shall apply:
Section 9. NR 210.06 (2) (a) is repealed and recreated to read:
NR 210.06 (2) (a) Bacterial indicators. 1. ‘Recreation protection.’ During the period of disinfection to protect recreational uses as determined under sub. (1) (a) or (c), all of the following shall apply:
a. The geometric mean of E. coli bacteria in effluent samples collected in any calendar month may not exceed 126 counts/100 mL.
Note: To calculate the geometric mean, a value of 1 should be used for any result of 0.
Note: As specified in ch. NR 102, Table A, for determining attainment or compliance with bacteria criteria or limits, counts are equivalent to either colony forming units or most probable number. b. No more than 10 percent of E. coli bacteria samples collected in any calendar month may exceed 410 counts/100 mL.
Note: U.S. EPA developed the E. coli criteria in s. NR 102.04 (6), on which these effluent limits are based using membrane filtration to count E. coli colony forming units. 2. ‘Public drinking water supply protection.’ If a facility is required to disinfect to protect public drinking water supplies outside of the recreation period specified in sub. (1) (a) or (c), it may either continue to meet the E. coli limits specified in par. (a) 1. year-round, or the geometric mean of the fecal coliform bacteria for effluent samples collected in a period of 30 consecutive days may not exceed 400 counts/100 mL.
Section 10. NR 210.06 (2) (b) (title) and (Note 2), and (3) (title) are created to read:
NR 210.06 (2) (b) (title) Chlorine.
Note: Compliance schedules for effluent limits established under this subsection are authorized in ch. NR 205.14 and procedures are detailed in ch. NR 106.117. Language on tentative and final determinations related to the permit, public notice processes, and review procedures are provided for all facilities in ch. NR 203. (3) (title) Disinfection determination.
Section 11. NR 210.06 (4) to (6) are repealed.
Section 12. NR 210.06 (7) is amended to read:
NR 210.06 (7) Disinfection continuation. In the absence of a specific determination under sub. (1), all dischargers which are required to disinfect as of the effective date of this ruleNovember 1, 1986 or thereafter shall continue to disinfect and comply with all terms of their WPDES permit in effect on that date.
Section 13. NR 219.04 Table A and table notes 1 to 33, and Table EM header row 2, Parameters “Fecal Coliform”, “Salmonella” (including sub-rows), and “Dioxins and Furans”, and table notes 8 and 11 are repealed and recreated to read:
NR 219.04
Table A
List of Approved Biological Methods for Wastewater and Sewage Sludge
Parameter and units | Analytical Technology 1 | EPA | Standard Methods 25,26 | AOAC, ASTM, USGS | Other |
1. Coliform (fecal), number per 100 mL or number per gram dry weight | Most Probable Number (MPN), 5 tube, 3 dilution, or | p. 1323 168011,15 168111,20 | 9221 E-2014 | | |
| Membrane filter (MF)2,5, single step | p. 1243 | 9222 D-201529 | B-0050-854 | |
2. Coliform (fecal), number per 100 mL | MPN, 5 tube, 3 dilution, or | p. 1323 | 9221 E-2014; 9221 F.2-201433 | | |
| Multiple tube/multiple well, or | | | | Colilert-18®13,18,28 |
| MF2,5, single step5 | p. 1243 | 9222 D-201529 | | |
3. Coliform (total), number per 100 mL | MPN, 5 tube, 3 dilution, or | p. 1143 | 9221 B-2014 | | |
| MF2,5, single step or two step | p. 1083 | 9222 B-201530 | B-0025-854 | |
| MF2,5 with enrichment | p. 1113 | 9222 (B+B.4e)-201530 | | |
4. E. coli, number per 100 mL | MPN6,8,16 multiple tube, or | | 9221 B.3-2014/9221 F-201412,14,33 | | |
| Multiple tube/multiple well, or | | 9223 B-201613 | 991.1510 | Colilert® 13 18
Colilert-18® 13,17,18 |
| MF2,5,6,7,8, two step, or | | 9222 B-2015/ 9222 I-201531 | | |
| Single step | 160321 | | | m-ColiBlue24®19 |
5. Fecal streptococci, number per 100 mL | MPN, 5 tube, 3 dilution, or | p. 1393 | 9230 B-2013 | | |
| MF2, or | p. 1363 | 9230 C-201332 | B-0055-854 | |
6. Enterococci, number per 100 mL | MPN, 5 tube, 3 dilution, or | p. 1393 | 9230 B-2013 | | |
| MPN6,8, multiple tube/multiple well, or | | 9230 D-2013 | D6503-999 | Enterolert® 13,23 |
| MF2,5,6,7,8 single step or | 160024 | 9230 C-201332 | | |
7. Salmonella number per gram dry weight11 | MPN multiple tube | 168222 | | | |
8. Toxicity, acute, fresh water organisms, percent effluent | Daphnia, Ceriodaphnia dubia, 48−h static− renewal mortality | | | | Note 27 |
| Fathead Minnow, Pimephales promelas, 96−h static renewal mortality, or 96−h flow−through mortality | | | | Note 27 |
9. Toxicity, chronic, fresh water organisms, percent effluent | Daphnia, Ceriodaphnia dubia, survival and reproduction | | | | Note 27 |
| Fathead minnow, Pimephales promelas, larval survival and growth | | | | Note 27 |
1 The method must be specified when results are reported.
2 A 0.45-µm membrane filter (MF) or other pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of extractables which could interfere with their growth.
3 Microbiological Methods for Monitoring the Environment, Water, and Wastes, EPA/600/8-78/017. 1978. U.S. EPA.
4 U.S. Geological Survey Techniques of Water-Resource Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples. 1989. USGS.
5 Because the MF technique usually yields low and variable recovery from chlorinated wastewaters, the Most Probable Number method will be required to resolve any controversies.
6 Tests must be conducted to provide organism enumeration (density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes to account for the quality, character, consistency, and anticipated organism density of the water sample.
7 When the MF method has been used previously to test waters with high turbidity, large numbers of noncoliform bacteria, or samples that may contain organisms stressed by chlorine, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of results.
8 To assess the comparability of results obtained with individual methods, it is suggested that side-by-side tests be conducted across seasons of the year with the water samples routinely tested in accordance with the most current Standard Methods for the Examination of Water and Wastewater or EPA alternate test procedure (ATP) guidelines.
9 Annual Book of ASTM Standards-Water and Environmental Technology, Section 11.02. 2000, 1999, 1996. ASTM International.
10 Official Methods of Analysis of AOAC International. 16th Edition, 4th Revision, 1998. AOAC International.
11 Recommended for enumeration of target organism in sewage sludge.
12 The multiple-tube fermentation test is used in 9221B.2-2014. Lactose broth may be used in lieu of lauryl tryptose broth (LTB), if at least 25 parallel tests are conducted between this broth and LTB using the water samples normally tested, and this comparison demonstrates that the false-positive rate and false-negative rate for total coliform using lactose broth is less than 10 percent. No requirement exists to run the completed phase on 10 percent of all total coliform-positive tubes on a seasonal basis.
13 These tests are collectively known as defined enzyme substrate tests.
14 After prior enrichment in a presumptive medium for total coliform using 9221B.2-2014, all presumptive tubes or bottles showing any amount of gas, growth or acidity within 48 h ± 3 h of incubation shall be submitted to 9221F-2014. Commercially available EC-MUG media or EC media supplemented in the laboratory with 50 µg/mL of MUG may be used.
15 Method 1680: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation Using Lauryl-Tryptose Broth (LTB) and EC Medium, EPA-821-R-14-009. September 2014. U.S. EPA.
16 Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert® may be enumerated with the multiple-well procedures, Quanti-Tray®, Quanti-Tray®/2000 and the MPN calculated from the table provided by the manufacturer.
17 Colilert-18® is an optimized formulation of the Colilert® for the determination of total coliforms and E. coli that provides results within 18 h of incubation at 35°C rather than the 24 h required for the Colilert® test and is recommended for marine water samples.
18 Descriptions of the Colilert®, Colilert-18®, Quanti-Tray®, and Quanti-Tray®/2000 may be obtained from IDEXX Laboratories, Inc.
19 A description of the mColiBlue24® test, is available from Hach Company.
20 Method 1681: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using A-1 Medium, EPA-821-R-06-013. July 2006. U.S. EPA.
21 Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified Membrane-Thermotolerant Escherichia coli Agar (modified mTEC), EPA-821-R-14-010. September 2014. U.S. EPA.
