CR 22-061 Rule Text

Wisconsin state drinking water maximum contaminant levels (MCLs) have been established, in ch. NR 809, Wis. Adm. Code, for Escherichia coli (E. coli) bacteria.

5. Plain Language Analysis:

Chapter 160, Wis. Stats., is Wisconsin’s Groundwater Standards Protection law. This chapter requires the department to develop numerical groundwater quality standards, consisting of enforcement standards and preventive action limits. Chapter NR 140, Wis. Adm. Code, establishes groundwater standards.

Proposed amendments to ch. NR 140, Wis. Adm. Code, add new groundwater quality standards for E. coli bacteria. E. coli bacteria is a type of coliform bacteria used as an indicator of fecal contamination in groundwater. Groundwater quality standards currently exist in ch. NR 140, Wis. Adm. Code, for total coliform bacteria. The department is proposing to revise the status of total coliform bacteria in ch. NR 140, Wis. Adm. Code, to make it an indicator parameter.

Minor revisions, to clarify rule language and update rule reference information, are also proposed to ch. NR 140, Wis. Adm. Code. These revisions include:

•

Revising order of Antimony and Anthracene in s. NR 140.10, Table 1 to correct their alphabetical order in the table.

•

Removing, in s. NR 140.20, Table 3, the indicator parameter for ammonia nitrogen. Health standards were established for ammonia (as N), in s. NR 140.10, Table 1, as part of the "Cycle 9" revisions to ch. NR 140.

•

Making needed additions and revisions to ch. NR 140 Appendix I to Table 1 substance names, Chemical Abstracts Service (CAS) registry numbers, and common synonyms.

6. Summary of, and Comparison with, Existing or Proposed Federal Statutes and Regulations:

The U.S. Environmental Protection Agency (US EPA) establishes health-based drinking water MCLs that are used to assess the quality of groundwater drinking water supplies. Federal drinking water MCLs are established based on scientific risk assessments and, in some cases, economic and technological considerations.

Under the federal Revised Total Coliform Rule (RTCR), the US EPA changed the regulatory status of total coliform bacteria in public drinking water systems. EPA replaced the MCL violation for total coliform bacteria with a treatment technique requirement and established an MCL for E. coli bacteria. Total coliform bacteria include bacteria that naturally occur in the environment, and total coliform are, with a few exceptions, not harmful to humans. Under the RTCR, detection of total coliform bacteria is used as an indicator of possible microbial pathways into a public drinking water system. The RTCR includes a "treatment technique" response for detection of total coliform bacteria in a water supply system. This response requires investigation of the sanitary condition of the system, and action to correct any defects found. E. coli bacteria are a sub-group of coliform bacteria considered to be a more specific indicator of fecal contamination and the potential for pathogens to be present in drinking water. Under the RTCR, detection of E. coli bacteria in a public water supply system is an MCL violation.

7. If Held, Summary of Comments Received During Preliminary Comment Period

and at Public Hearing on the Statement of Scope:

A preliminary public hearing on Statement of Scope SS 021-22, related to revisions to ch. NR 140, was held on April 22, 2022. Comments on the proposed scope were accepted through April 22, 2022. One comment was received requesting the department revise the scope statement to specify that only the substances E. coli bacteria and total coliform bacteria would be addressed under this rulemaking.

8. Comparison with Similar Rules in Adjacent States:

Minnesota, Michigan, Illinois, and Iowa use groundwater protection values/levels/standards in their regulation of practices and activities that might impact the quality of groundwater. Minnesota, Michigan, and Illinois have not established individual state groundwater protection standards for total coliform or E. coli bacteria but, because bacteria are present everywhere in the environment, including groundwater, these states all recommend regular testing of private drinking water supply wells for total coliform bacteria (which includes E. coli bacteria). Iowa uses established federal standards (such as federal drinking water MCLs) as its state groundwater protection standards. In accordance with Iowa Environmental Protection Regulations 567 IAC Chapter 133, Iowa uses established federal drinking water MCLs as "Action Levels" in its regulation of practices and activities that may adversely impact groundwater quality. Federal drinking water MCLs have been established for E. coli bacteria.

9. Summary of Factual Data and Analytical Methodologies Used and How Any Related Findings Support the Regulatory Approach Chosen:

In accordance with s. 160.07, Wis. Stats., the department is required, for substances of public health concern, to propose rules establishing recommendations from DHS as state groundwater quality enforcement standards. In accordance with s. 160.15, Wis. Stats., the department is required to establish by rule a preventive action limit for each substance for which an enforcement standard is established.

To develop proposed groundwater standards, DHS follows the process described in ss. 160.07 to 160.17, Wis. Stats. This includes a review of federal numbers, state drinking water standards, and acceptable daily intake values from the US EPA, research studies and a search of peer-reviewed scientific research. DHS then develops a scientific support document describing the findings of their review and basis for the recommended proposed groundwater standards. DHS provided the department its recommendations for groundwater quality standards for the protection of public health in a document titled, Recommended Public Health Groundwater Quality Standards, Scientific Support Documents for "Cycle 10" Substances, January 2022.

DHS recommended new standards for 17 substances: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), hexavalent chromium, strontium, thiamethoxam, imidacloprid, clothianidin, isoxaflutole, isoxaflutole DKN degradate, isoxaflutole BA degradate, thiencarbazone-methyl, Dacthal TPA and MTP degradates, glyphosate, glyphosate aminomethylphosphonic acid (AMPA) degradate, sulfentrazone, and E. coli bacteria.

DHS also provided recommendations for revisions to existing public health related state groundwater quality standards for 8 additional substances: trichloroethylene (TCE), tetrachloroethylene (PCE), 1,2,3-trichloropropane (1,2,3-TCP), 1,4-dioxane, aluminum, boron, molybdenum and cobalt.

In 2019, the department began rulemaking for all “Cycle 10” substances, including E. coli. That proposed rule was brought to the Natural Resources Board for adoption on February 23, 2023, and was not adopted. The scope statement for that rulemaking effort expired in March 2022 without the rule being promulgated.

In this rule, the department is proposing establishing the DHS enforcement standard recommendations and accompanying preventive action limit for E. coli bacteria in ch. NR 140, Wis. Adm. Code, state groundwater quality protection standards. The department is also proposing to remove the enforcement standard for total coliform bacteria and replace it with an indicator parameter preventative action limit, per s. 160.15(3), Wis. Stats.

10. Analysis and Supporting Documents Used to Determine the Effect on Small Business or in Preparation of an Economic Impact Report:

Chapter NR 140, Wis. Adm. Code, is not a self-implementing administrative rule and is independent from the regulatory programs that contain actions, requirements, responses, and enforcement mechanisms for the various activities or facilities they regulate. The cost of implementation and compliance for groundwater standards is dictated entirely by the regulatory agencies and their numerous regulatory programs based on authority outside of ch. NR 140, Wis. Adm. Code. Implementation and compliance costs for regulatory agencies may change after they complete their statutorily required review of new or amended groundwater standards and, if necessary, amend or create administrative rules to ensure compliance with new groundwater standards.

The department does not anticipate any economic impacts related to establishing groundwater quality standards for E. coli bacteria or revising the status of total coliform bacteria in ch. NR 140, Wis. Adm. Code, to make it an indicator parameter. An exceedance of the E. coli bacteria standard is already an exceedance of the existing total coliform bacteria standard in ch. NR 140, Wis. Adm. Code. Therefore, the department calculates that the proposed amendments will result in decreased costs compared to the current rule, as a smaller subset of groundwater that currently tests positive for total coliform bacteria will end up testing positive for E. coli bacteria.

11. Effect on Small Business (initial regulatory flexibility analysis):

The department does not anticipate that this rule will impact any specific business or business sector.

12. Agency Contact Person: Bruce Rheineck; 101 S. Webster Street, Madison, WI 53703; [e-mail]; [phone]

13. Place where comments are to be submitted and deadline for submission:

A comment period on the rule was held from September 26, 2022 to October 28, 2022. A public hearing was held on October 21, 2022.

RULE TEXT

Section 1   NR 140.10 Table 1 is amended to read:

NR 140.10 Table 1

Table 1 Public Health Groundwater Quality Standards

Substance1

Enforcement Standard (micrograms per liter - except as noted)

Preventive Action Limit (micrograms per liter - except as noted)

Acetochlor

7

0.7

Acetochlor ethane sulfonic acid + oxanilic acid (Acetochlor - ESA + OXA)

230

46

Acetone

9 milligrams/liter (mg/1)

1.8 mg/1

Alachlor

2

0.2

Alachlor ethane sulfonic acid (Alachlor - ESA)

20

4

Aldicarb

10

2

Aluminum

200

40

Ammonia (as N)

9.7 mg/l

0.97 mg/l

Antimony

6

1.2

Anthracene

3000

600

Antimony

6

1.2

Arsenic

10

1

Asbestos

7 million fibers per liter (MFL)

0.7 MFL

Atrazine, total chlorinated residues

32

0.32

Bacteria, E. coli

0

0

Bacteria, Total Coliform

03

03

Barium

2 milligrams/liter (mg/l)

0.4 mg/l

Bentazon

300

60

Benzene

5

0.5

Benzo(b)fluoranthene

0.2

0.02

Benzo(a)pyrene

0.2

0.02

Beryllium

4

0.4

Boron

1000

200

Bromodichloromethane

0.6

0.06

Bromoform

4.4

0.44

Bromomethane

10

1

Butylate

400

80

Cadmium

5

0.5

Carbaryl

40

4

Carbofuran

40

8

Carbon disulfide

1000

200

Carbon tetrachloride

5

0.5

Chloramben

150

30

Chlordane

2

0.2

Chlorodifluoromethane

7 mg/l

0.7 mg/l

Chloroethane

400

80

Chloroform

6

0.6

Chlorpyrifos

2

0.4

Chloromethane

30

3

Chromium (total)

100

10

Chrysene

0.2

0.02

Cobalt

40

8

Copper

1300

130

Cyanazine

1

0.1

Cyanide, free4 3

200

40

Dacthal

70

14

1,2-Dibromoethane (EDB)

0.05

0.005

Dibromochloromethane

60

6

1,2-Dibromo-3-chloropropane (DBCP)

0.2

0.02

Dibutyl phthalate

1000

100

Dicamba

300

60

1,2-Dichlorobenzene

600

60

1,3-Dichlorobenzene

600

120

1,4-Dichlorobenzene

75

15

Dichlorodifluoromethane

1000

200

1,1-Dichloroethane

850

85

1,2-Dichloroethane

5

0.5

1,1-Dichloroethylene

7

0.7

1,2-Dichloroethylene (cis)

70

7

1,2-Dichloroethylene (trans)

100

20

2,4-Dichlorophenoxyacetic Acid (2,4-D)

70

7

1,2-Dichloropropane

5

0.5

1,3-Dichloropropene (cis/trans)

0.4

0.04

Di (2-ethylhexyl) phthalate

6

0.6

Dimethenamid/Dimethenamid-P

50

5

Dimethoate

2

0.4

2,4-Dinitrotoluene

0.05

0.005

2,6-Dinitrotoluene

0.05

0.005

Dinitrotoluene, Total Residues5 4

0.05

0.005

Dinoseb

7

1.4

1,4-Dioxane

3

0.3

Dioxin (2, 3, 7, 8-TCDD)

0.00003

0.000003

Endrin

2

0.4

EPTC

250

50

Ethylbenzene

700

140

Ethyl ether

1000

100

Ethylene glycol

14 mg/l

2.8 mg/l

Fluoranthene

400

80

Fluorene

400

80

Fluoride

4 mg/l

0.8 mg/l

Fluorotrichloromethane

3490

698

Formaldehyde

1000

100

Heptachlor

0.4

0.04

Heptachlor epoxide

0.2

0.02

Hexachlorobenzene

1

0.1

N-Hexane

600

120

Hydrogen sulfide

30

6

Lead

15

1.5

Lindane

0.2

0.02

Manganese

300

60

Mercury

2

0.2

Methanol

5000

1000

Methoxychlor

40

4

Methylene chloride

5

0.5

Methyl ethyl ketone (MEK)

4 mg/l

0.8 mg/l

Methyl isobutyl ketone (MIBK)

500

50

Methyl tert-butyl ether (MTBE)

60

12

Metolachlor/s-Metolachlor

100

10

Metolachlor ethane sulfonic acid + oxanilic acid (Metolachlor - ESA + OXA)

1.3 mg/l

0.26 mg/l

Metribuzin

70

14

Molybdenum

40

8

Monochlorobenzene

100

20

Naphthalene

100

10

Nickel

100

20

Nitrate (as N)

10 mg/l

2 mg/l

Nitrate + Nitrite (as N)

10 mg/l

2 mg/l

Nitrite (as N)

1 mg/1

0.2 mg/l

N-Nitrosodiphenylamine

7

0.7

Pentachlorophenol (PCP)

1

0.1

Perchlorate

1

0.l

Phenol

2 mg/l

0.4 mg/l

Picloram

500

100

Polychlorinated biphenyls (PCBs)

0.03

0.003

Prometon

100

20

Propazine

10

2

Pyrene

250

50

Pyridine

10

2

Selenium

50

10

Silver

50

10

Simazine

4

0.4

Styrene

100

10

Tertiary Butyl Alcohol (TBA)

12

1.2

1,1,1,2-Tetrachloroethane

70

7

1,1,2,2-Tetrachloroethane

0.2

0.02

Tetrachloroethylene

5

0.5

Tetrahydrofuran

50

10

Thallium

2

0.4

Toluene

800

160

Toxaphene

3

0.3

1,2,4-Trichlorobenzene

70

14

1,1,1-Trichloroethane

200

40

1,1,2-Trichloroethane

5

0.5

Trichloroethylene (TCE)

5

0.5

2,4,5-Trichlorophenoxy-propionic acid (2,4,5-TP)

50

5

1,2,3-Trichloropropane

60

12

Trifluralin

7.5

0.75

Trimethylbenzenes (1,2,4- and 1,3,5- combined)

480

96

Vanadium

30

6

Vinyl chloride

0.2

0.02

Xylene6 5

2 mg/l

0.4 mg/l

1 Appendix I contains Chemical Abstract Service (CAS) registry numbers, common synonyms and trade names for most substances listed in Table 1.

2 Total chlorinated atrazine residues includes parent compound and the following metabolites of health concern: 2-chloro-4-amino-6-isopropylamino-s-triazine (formerly deethylatrazine), 2-chloro-4-amino-6-ethylamino-s-triazine (formerly deisopropylatrazine) and 2-chloro-4,6-diamino-s-triazine (formerly diaminoatrazine).

3 Total coliform bacteria may not be present in any 100 ml sample using either the membrane filter (MF) technique, the presence-absence (P-A) coliform test, the minimal medium ONPG-MUG (MMO-MUG) test or not present in any 10 ml portion of the 10-tube multiple tube fermentation (MTF) technique.

4 3 “Cyanide, free" refers to the simple cyanides (HCN, CN-) and /or readily dissociable metal-cyanide complexes. Free cyanide is regulatorily equivalent to cyanide quantified by approved analytical methods for “amenable cyanide" or “available cyanide".

5 4 Dinitrotoluene, Total Residues includes the dinitrotoluene (DNT) isomers: 2,3-DNT, 2,4-DNT, 2,5-DNT, 2,6-DNT, 3,4-DNT and 3,5-DNT.

6 5 Xylene includes meta-, ortho-, and para-xylene combined.

Section 2   NR 140.16 (1) (d) is amended to read:

NR 140.16 (1) (d) Laboratory requirements. All groundwater quality samples, except samples collected for total coliform bacteria laboratory analysis and, E. coli laboratory analysis, field analyses for pH, field analysis for specific conductance, and field analysis for temperature, shall be analyzed in accordance with provisions under ch. NR 149 by a laboratory certified or registered under ch. NR 149. Samples for total coliform bacteria and E. coli analysis shall be analyzed by the state laboratory of hygiene or at a laboratory approved or certified by the department of agriculture, trade and consumer protection.

Section 3   NR 140.20 (2) (intro.) is amended to read:

  NR 140.20 (2) Establishing preventative action limits for indicator parameters. For each indicator parameter, except total coliform bacteria, for which groundwater monitoring is required by the department, the preventive action limit shall be established based upon a change of water quality with respect to background water quality according to the methodology specified in pars. (a) to (c) and in Table 3. any of the following:

Section 4   NR 140.20 (3) is created to read:  

  NR 140.20 (3) Total coliform bacteria indicator parameter. The preventive action limit for total coliform bacteria is 0. If the source of total coliform bacteria is determined to be from a regulated facility, practice, or activity, response actions under s. NR 140.24 may be required.

Section 5   NR 140.20 Table 3 is amended to read:

NR 140.20 Table 3

Table 3
Methodology for Establishing Preventive Action Limit for Indicator Parameters

Parameter

Minimum Increase (mg/l)

Alkalinity

100

Biochemical oxygen demand (BOD5)

25

Calcium

25

Chemical oxygen demand (COD)

25

Magnesium

25

Nitrogen series

Ammonia nitrogen

2

Organic nitrogen

2

Total nitrogen

5

Potassium

5

Sodium

10

Field specific conductance

200 microSiemens/cm

Total dissolved solids (TDS)

200

Total hardness

100

Total organic carbon (TOC)

1

Total organic halogen (TOX)

0.25

Section 6   NR 140.24 (3) (intro.) is amended to read:

NR 140.24 (3) Range of responses for indicator parameters. Except as otherwise provided in this subsection, the range of responses whichthat the department may take or may require if a preventive action limit for an indicator parameter identified in Table 3 has been attained or exceeded, is one or more of the responses in items 1 to 4 in Table 5. If total coliform bacteria are detected at a facility, practice, or activity groundwater monitoring point, that monitoring point shall be sampled for E. coli bacteria. The range of responses that the department may take or may require if a preventive action limit for total coliform bacteria has been attained or exceeded, is one or more of the responses in Table 5. The range of responses is one or more of the responses in items 1 to 6 of Table 5 in the event the department determines that:

Section 7   NR 140 Appendix I to Table 1 is amended to read:

NR 140 Appendix I to Table 1

CHAPTER NR 140

APPENDIX I TO TABLE 1

PUBLIC HEALTH GROUNDWATER QUALITY STANDARDS

Substance

CAS RN1

Common synonyms/Tradename2

Acetochlor

34256−82−1

Cadence, Degree, Harness, Keystone, Over-time, Volley

Acetochlor ethane sulfonic acid + oxanilic acid

187022−11−3 (ESA) 184992−44−4 (OXA)

Acetochlor − ESA + OXA

Acetone

67−64−1

Propanone

Alachlor

15972−60−8

Lasso

Alachlor ethane sulfonic acid

142363−53−9

Alachlor−ESA, Alachlor Ethane Sulfonate, MON 5775

Aldicarb

116−06−3

Temik

Aluminum

7429−90−5

Ammonia

7664−41−7

Anthracene

120−12−7

Para−naphthalene

Asbestos

1332−21−4

Bentazon

25057−89−0

Basagran

Benzene

71−43−2

Benzo(b)fluoranthene

205−99−2

B(b)F,3,4−Benzofluoranthene

Benzo(a)pyrene

50−32−8

BaP, B(a)P

Boron

7440−42−8

Bromodichloromethane

75−27−4

Dichlorobromomethane, BDCM

Bromoform

75−25−2

Tribromomethane

Bromomethane

74−83−9

Methyl bromide

Butylate

2008−41−5

S−ethyl di−isobutylthiocarbamate, Sutan+

Carbaryl

63−25−2

Sevin

Carbofuran

1563−66−2

Furadan

Carbon disulfide

75−15−0

Carbon bisulfide

Carbon tetrachloride

56−23−5

Tetrachloromethane, Perchloroethane

Chloramben

133−90−4

Chlordane

57−74−9

Chlorodifluoromethane

75−45−6

HCFC−22, Freon 22

Chloroethane

75−00−3

Ethyl chloride, Monochloroethane

Chloroform

67−66−3

Trichloromethane

Chlorpyrifos

2921−88−2

Dursban, Lorsban, Warhawk, Hatchet, Yuma, Whirlwind, Eraser

Chloromethane

74−87−3

Methyl chloride

Chromium (total)

7440−47−3

Chrysene

218−01−9

1,2−Benzphenanthrene

Cobalt

7440−48−4

Cyanazine

21725−46−2

Bladex , 2−chloro−4−ethylamino−6− nitriloisopropylamino−s−triazine

Cyanide, free

57−12−5

Dacthal

1861−32−1

DPCA, Chlorothal, Dacthalor, 1,4−benzene- dicarboxylic acid

Dibromochloromethane

124−48−1

Chlorodibromomethane, DBCM

1,2−Dibromo−3−chloropropane

96−12−8

DBCP, Dibromochloropropane

1,2−Dibromoethane

106−93−4

EDB, Ethylene dibromide, Dibromoethane

Dibutyl phthalate

84−74−2

DP, Di−n−butyl phthalate, n−Butyl phthalate

Dicamba

1918−00−9

Banvel

1,2−Dichlorobenzene

95−50−1

o−Dichlorobenzene, o−DCB

1,3−Dichlorobenzene

541−73−1

m−Dichlorobenzene, m−DCB

1,4−Dichlorobenzene

106−46−7

p−Dichlorobenzene, p−DCB

Dichlorodifluoromethane

75−71−8

Freon 12

1,1,−Dichloroethane

75−34−3

Ethylidine chloride

1,2−Dichloroethane

107−06−2

1,2−DCA, Ethylene dichloride

1,1−Dichloroethylene

75−35−4

1,1−DCE, 1,1−Dichloroethene, Vinylidene chloride

1,2−Dichloroethylene (cis)

156−59−2

cis−Dichloroethylene, 1,2−Dichloroethene (cis)

1,2−Dichloroethylene (trans)

156−60−5

trans−1,2−Dichloroethylene

2,4−Dichlorophenoxyacetic acid

94−75−7

2,4−D

1,2−Dichloropropane

78−87−5

Propylene dichloride

1,3−Dichloropropene (cis/trans)3

542−75−6

Telone, DCP, Dichloropropylene

Di(2−ethylhexyl) phthalate

117−81−7

DEHP, Bis(2−ethylhexyl) phthalate, 1,2−Benzenedicarboxylic acid, Bis (2−ethyl- hexyl)ester

Dimethenamid/Dimethinamid−P

87674−68−8 163515−14−8 (−P)

Frontier, Outlook, Propel, Establish, Sortie, Tower

Dimethoate

60−51−5

2,4−Dinitrotoluene

121−14−2

2,4−DNT, 1−methyl−2,4−dinitrobenzene

2,6−Dinitrotoluene

606−20−2

2,6−DNT, 2−methyl−1,3−dinitrobenzene

Dinitrotoluene, Total Residues

25321−14−6

Dinitrotoluene, DNT

Dinoseb

88−85−7

2−(1−methylpropyl)−4,6−dinitrophenol

1,4−Dioxane

123−91−1

p−Dioxane

Dioxin

1746−01−6

2,3,7,8−TCDD,2,3,7,8−Tetrachlorodibenzo− p−dioxin

Endrin

72−20−8

EPTC

759−94−4

Eptam, Eradicane

Ethylbenzene

100−41−4

Phenylethane, EB

Ethyl ether

60−29−7

Diethyl Ether

Ethylene glycol

107−21−1

Fluoranthene

206−44−0

Benzo(jk)fluorene

Fluorene

86−73−7

2,3−Benzidine, Diphenylenemethane

Fluoride

7681−49−4

Fluorotrichloromethane

75−69−4

Freon11, Trichlorofluoromethane

Formaldehyde

50−00−0

Heptachlor

76−44−8

Velsicol

Heptachlor epoxide

1024−57−3

Hexachlorobenzene

118−74−1

Perchlorobenzene, Granox

N−Hexane

110−54−3

Hexane, Skellysolve B

Hydrogen sulfide

7783−06−4

Dihydrogen sulfide

Lindane

58−89−9

Manganese

7439−96−5

Mercury

7439−97−6

Methanol

67−56−1

Methyl alcohol, Wood alcohol

Methoxychlor

72−43−5

Methylene chloride

75−09−2

Dichloromethane, Methylene dichloride

Methyl ethyl ketone

78−93−3

MEK, 2−Butanone

Methyl isobutyl ketone

108−10−1

MIBK, 4−Methyl−2−pentanone, Isopropyla- cetone, Hexone

Methyl tert−butyl ether

1634−04−4

MTBE, 2−Methoxy−2−methyl−propane, tert−Butyl methyl ether

Metolachlor/s−Metolachlor

51218−45−2 87392−12−9 (s−)

Dual, Bicep, Milocep, Stalwart, Parallel, Prefix, Charger, Brawl, Cinch, Dual Mag- num, Boundary

Metolachlor ethane sulfonic acid + oxanilic acid

171118−09−5 (ESA) 152019−73−3 (OXA)

Metolachlor − ESA + OXA

Metribuzin

21087−64−9

Sencor, Lexone

Molybdenum

7439−98−7

Monochlorobenzene

108−90−7

Chlorobenzene

Naphthalene

91−20−3

N−Nitrosodiphenylamine

86−30−6

NDPA

Pentachlorophenol

87−86−5

PCP, Pentachlorohydroxybenzene

Perchlorate

14797−73−0

Perchlorate and perchlorate salts, Perchlo-rate ion

Phenol

108−95−2

Picloram

1918−02−1

Tordon, 4−amino−3,5,6−trichloropicolinic acid

Polychlorinated biphenyls4

PCBs

Prometon

1610−18−0

Pramitol, Prometone

Pyrene

129−00−0

Benzo(def)phenanthrene

Pyridine

110−86−1

Azabenzene

Simazine

122−34−9

Princep, 2−chloro−4,6−diethylamino− s−tri- azine

Styrene

100−42−5

Ethenylbenzene, Vinylbenzene

Tertiary Butyl Alcohol

75−65−0

TBA

1,1,1,2−Tetrachlorethane

630−20−6

1,1,1,2−TCA, 1,1,1,2−PCA

1,1,2,2,−Tetrachloroethane

79−34−5

1,1,2,2−TCA, 1,1,2,2−PCA

Tetrachloroethylene

127−18−4

Perchloroethylene, PERC, Tetrachloroethene

Tetrahydrofuran

109−99−9

THF

Toluene

108−88−3

Methylbenzene

Toxaphene

8001−35−2

1,2,4−Trichlorobenzene

120−82−1

1,1,1−Trichloroethane

71−55−6

Methyl chloroform, 1,1,1−TCA

1,1,2−Trichloroethane

79−00−5

1,1,2−TCA, Vinyl trichloride

Trichloroethylene

79−01−6

TCE, Chloroethene

2,4,5−Trichlorophenoxy− propionic acid

93−72−1

2,4,5−TP, Silvex

1,2,3−Trichloropropane

96−18−4

1,2,3−TCP, Glycerol trichlorohyrin

Trifluralin

1582−09−8

Treflan

1,2,4−Trimethylbenzene

95−63−6

1,3,5−Trimethylbenzene

108−67−8

Vanadium

7440−62−2

Vinyl chloride

75−01−4

VC, Chloroethene

Xylene5

1Chemical Abstracts Service (CAS) registry numbers are unique numbers assigned to a chemical substance. The CAS registry numbers were published by the U.S. Environmental Protection Agency in 40 CFR Part 264, Appendix IV 2Common synonyms include those widely used in government regulations, scientific publications, commerce and the general public. A trade name, also known as the proprietary name, is the specific, registered name given by a manufacturer to a product. Trade names are listed in italics. Common synonyms and trade names should be cross-referenced with CAS registry number to ensure the correct substance is identified. Table 1 contains groundwater quality standards for pesticide active ingredients and their degradation breakdown products. Active ingredients are the chemicals in a pesticide product that kill, control, or repel pests. Pesticide products are given proprietary “trade names” by the pesticide product manufacturer. A database of pesticide products approved for use in Wisconsin is accessible through the Department of Agriculture, Trade and Consumer Protection (DATCP) home web page (search for "pesticide database"). The U.S. Environmental Protection Agency (EPA) also maintains a database of registered pesticide products, called the Pesticide Product and Label System (PPLS), on its website. These pesticide product databases can be searched by active ingredient to find the pesticide products, and their trade names, that contain a specific pesticide active ingredient. 3This is a combined chemical substance which includes cis 1,3-Dichloropropene (CAS RN 10061-01-5) and trans 1,3-Dichloropropene (CAS RN 10061-02-6). 4Polychlorinated biphenyls (CAS RN 1336-36-3); this category contains congener chemicals (same molecular composition, different molecular structure and formula), including constituents of Aroclor-1016 (CAS RN12674-11-2), Aroclor-1221 (CAS RN 11104-28-2), Aroclor-1232 (CAS RN 11141-16-5), Aroclor-1242 (CAS RN 53469-21-9), Aroclor-1248 (CAS RN 12672-29-6), Aroclor-1254 (CAS RN 11097-69-1), and Aroclor-1260 (CAS RN 11096-82-5). 5Xylene (CAS RN 1330-20-7) refers to a mixture of three isomers, meta-xylene (CAS RN 108-38-3), ortho-xylene (CAS RN 95-47-6), and para-xylene (CAS RN 106-42-3)

Section 8 Effective Date. This rule takes effect on the first day of the month following publication in the Wisconsin Administrative Register as provided in s. 227.22 (2) (intro.), Stats.

Section 9 Board adoption. This rule was approved and adopted by the State of Wisconsin Natural Resources Board on January 25, 2023.

Dated at Madison, Wisconsin _____________________________.