Montana Administrative Register Notice 17-422 No. 10   05/27/2022    
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In the matter of the amendment of ARM 17.36.345, 17.38.101, 17.38.209, Department Circular PWS-5 regarding ground water under the direct influence of surface water determinations, and section 3.2.2 and Appendix A of Circular DEQ-1 regarding standards for public water supply systems














TO: All Concerned Persons


            1. On June 17, 2022, at 10:00 a.m., the Department of Environmental Quality will hold a public hearing in Room 111 of the Metcalf Building, 1520 East Sixth Avenue, Helena, Montana, to consider the proposed amendment of the above-stated rules.

            DEQ is committed to preventing the spread of COVID-19 and promoting the health and wellness of others. Members of the public may participate either in-person or virtually. For in-person meetings, while face masks are not required, meeting attendees are welcome to wear masks. If you are not feeling well, please do not attend the in-person meeting. Registration with Zoom may be made at the following link: 


Passcode: 655654


Or One tap mobile :

    US: +12133388477,,85115235223#,,,,*655654# or +12063379723,,85115235223#,,,,*655654#

Or Telephone:

    Dial(for higher quality, dial a number based on your current location):

        US: +1 213 338 8477 or +1 206 337 9723 or +1 646 558 8656

Webinar ID: 851 1523 5223

Passcode: 655654

    International numbers available: https://mt-gov.zoom.us/u/kgGWKsvUv


Or an H.323/SIP room system:

    H.323: (US West) or (US East)

    Meeting ID: 851 1523 5223

    Passcode: 655654

    SIP: 85115235223@zoomcrc.com

    Passcode: 655654


2. The department will make reasonable accommodations for persons with disabilities who wish to participate in this rulemaking process or need an alternative accessible format of this notice. If you require an accommodation, contact the department, no later than 5:00 p.m., June 12, 2022, to advise us of the nature of the accommodation that you need.  Please contact the Department of Environmental Quality at P.O. Box 200901, Helena, Montana 59620-0901; phone (406) 444-1388; fax (406) 444-4386; or e-mail DEQGWUDISWRule2022@mt.gov.


3. The rules proposed to be amended provide as follows, new matter underlined, deleted matter interlined:


17.36.345 ADOPTION BY REFERENCE (1) For purposes of this chapter, the department adopts and incorporates by reference the following documents.  All references to these documents in this chapter refer to the edition set out below:

(a)  Department Circular DEQ-1, "Standards for Water Works," 2018 2022 edition;

(b) through (j) remain the same.

(k)  Department Circular PWS-5, "Ground Water Under the Direct Influence of Surface Water Evaluation," 2002 2022 edition;

(l) through (2) remain the same.


AUTH: 76-4-104, MCA

IMP: 76-4-104, MCA


REASON: The proposed changes to ARM 17.36.345, which would incorporate into the department's subdivision rules the changes to DEQ-1 and PWS-5 discussed elsewhere in this notice of proposed rulemaking, are necessary to ensure that all of the department's programs are using the same and most recent editions of the circulars.


17.38.101  PLANS FOR PUBLIC WATER SUPPLY OR PUBLIC SEWAGE SYSTEM (1) through (19) remain the same.

(20)  For purposes of this chapter, the board adopts and incorporates by reference the following documents.  All references to these documents in this chapter refer to the edition set out below:

(a)  Department Circular DEQ-1, 2018 2022 edition, which sets forth the requirements for the design and preparation of plans and specifications for public water supply systems;

(b) through (21) remain the same.


AUTH: 75-6-103 75-6-104, MCA

IMP: 75-6-103 75-6-104, MCA


REASON: The proposed change to ARM 17.38.101, which would incorporate into the department's public water and wastewater engineering rules the changes to DEQ-1 discussed elsewhere in this notice of proposed rulemaking, is necessary to ensure that all of the department's programs are using the same and most recent of the circular. 


            17.38.209  GROUND WATER UNDER THE DIRECT INFLUENCE OF SURFACE WATER DETERMINATIONS  (1) The board department adopts and incorporates by reference the Department of Environmental Quality Circular PWS-5, Ground Water Under the Direct Influence of Surface Water Evaluation, 2008 2022 edition, which sets forth the standards for making ground water under the direct influence of surface water determinations.


AUTH: 75-6-103 75-6-104, MCA

IMP: 75-6-103 75-6-104, MCA


REASON:  States that administer their own drinking water programs, such as Montana, are required to provide a description of how the state determines which systems using a ground water source are under the direct influence of surface water (GWUDISW). 40 C.F.R. § 141.16(b)(2)(i)(B). While the Environmental Protection Agency (EPA) requires that states to determine which systems are GWUDISW, it leaves the specifics of that determination to each state.  Montana has adopted procedures for making the GWUDISW classification in Department Circular PWS-5, which has not been revised since 2008. The department now proposes to adopt a revised 2022 edition of Department Circular PWS-5 (proposed Circular).  

The most significant changes proposed by the department include transferring assessment and testing responsibilities from system owners to the department; modifying the criteria and scores in the preliminary assessment (PA); emphasizing that microparticulate analyses (MPA) are the determining factor in the GWUDISW classification; updating the circular to be consistent with other recently adopted rules; and removing extraneous nonregulatory information. Each section of the proposed Circular is discussed below. 

Section 1 of the proposed Circular provides a general introduction explaining the Circular's purpose and how the Circular protects public health.

Section 2 of the proposed Circular provides definitions for types of ground water sources used in the Circular. In Section 2.1 and 2.4, the proposed Circular defines the terms "subsurface water source" and "ground water" to differentiate between ground water generally and water that, after evaluation, is not surface water or GWUDISW. The definitions of "surface water" and "ground water under the direct influence of surface water" in Sections 2.2 and 2.3 remain the same as the existing requirements, except that the proposed description of surface water allows the department to exclude temporary surface water bodies if they are unlikely to harbor or transport surface water bodies and do not provide an environment for Giardia and Cryptosporidum cysts to be collected and transported to the groundwater.  Without exclusion of these water bodies in the PA, many subsurface water sources would be required to undergo an unnecessary MPA.

Section 3 of the proposed Circular is an applicability section that requires each subsurface water source that serves or is intended to serve a public water supply system be evaluated to determine whether the source is GWUDISW. This is necessary because all water sources piped to the water system have the possibility of contributing contaminated water to the rest of the system.  

Section 4 of the proposed Circular describes the GWUDISW evaluation process, including the PA and the MPA. Because each GWUDISW analysis is source-specific, this section explicitly provides that the department may rely on all other relevant information in making the GWUDISW classification. To effectively gather that information, this section requires owners of public water systems to provide additional information if requested by the department.

Section 4.1 of the proposed Circular describes the PA process. The PA allows the department to screen out water sources that are easily classified as ground water and focus on those sources that need further review. To do this, the PA looks at various factors relevant to surface water influence and assigns point values relative to the risk of surface water influence on the source. Sources that score more than 40 points on the PA warrant further review. 

The proposed Circular maintains the existing score of 40 points for springs, horizontal wells, and infiltration galleries. These sources, by design or construction, are more likely to be influenced by surface water and warrant further review. For purposes of classification under the Circular only, infiltration galleries are treated as a type of horizontal well due to constraints with the EPA database for public water supply systems.

The proposed Circular maintains the existing score of 40 points for sources with a history of or a suspected outbreak of Giardia or other pathogenic organisms associated with surface water for the current system configuration. Protecting drinking water supplies from such organisms is the very purpose of the GWUDISW evaluation process.

The existing circular assigns scores for a record of acute maximum contaminant level (MCL) violations of the Total Coliform Rule. The proposed Circular modifies this criterion in favor of the number of E. coli-positive distribution samples in the previous three years, with 5 points for one positive sample and 10 points for two or more samples.  These changes are necessary to remove references to the Total Coliform Rule and the total coliform MCL, which were superseded in 2016 by EPA's promulgation of the Revised Total Coliform Rule. These changes are also necessary to incorporate E. coli source samples, which were not required before the 2009 Groundwater Rule. The proposed changes do not score additional points for more than two positive E. coli distribution samples, since two samples already indicates a repeatable presence of contamination, and additional samples would provide minimal new information.  

The proposed Circular includes a new score for positive E. coli source samples, which is weighted more heavily than distribution samples. This is necessary because source samples give more direct evidence of ground water contamination than distribution samples, which can be influenced by any component of the water system. Further, the presence of E. coli in ground water indicates that the bacteria traveled from the digestive tract of a warm-blooded animal to the ground water sample in less than 72 hours, which provides strong evidence of direct surface water influence.

The proposed Circular maintains the existing score of 5 points for DEQ-verified complaints about turbidity. Turbidity is a physical property of water quality that provides some supporting evidence of direct surface water influence.

The proposed Circular maintains the existing scores based on the horizontal distance between the source and surface water. The risk that a ground water source is under the direct influence of surface water is less likely the farther the source is from the surface water. Generally, water sources that are farther from surface water have undergone more filtration and thus may be scored lower on the PA.  Water sources less than 100 feet from surface water are close enough to question whether there is sufficient filtration and thus are scored 40 points, requiring further review and MPAs. As mentioned above, the department may exclude from this separation distance those temporary surface water bodies that are unlikely to harbor or transport surface water organisms to the ground water.

The existing circular includes a single score of 15 points for poorly constructed wells, which it describes as uncased wells or those where the annular space is not sealed to a depth of at least 18 feet below the land surface. The proposed Circular adds specificity by defining the key elements of proper well construction relevant to surface water influence. The proposed changes would require evaluation of well casing, annular seal thickness, and depth of sealing material, which are the most important construction features for protecting the well from surface water contamination.

With regard to well casing, the proposed Circular specifies that the well must be cased to at least the top of the water-bearing unit. This is because a casing to a shallower depth increases the risk of surface water influence. The proposed Circular also updates the depth of sealing material to the modern standard of 25 feet, which has been a requirement included in the well drillers' rules since 2010 and in Department Circular DEQ-1 since 2014. Because the shallowest casing joint is often at 18 feet, wells with less than 25 feet of sealing material have a greater risk of direct surface water influence. The last proposed change for well construction requires a borehole diameter of at least 3 inches greater than the casing diameter, which provides a better likelihood of proper seal than a lesser diameter. Further, the 3-inch requirement is consistent with long-existing well drillers' rules and provides indicia of proper well construction.

The existing circular provides criteria and scores for well intake construction and static water level for wells in unconfined or semi-confined aquifers. The proposed Circular removes the reference to unconfined and semi-confined aquifers. Determining whether an aquifer is unconfined or semi-confined requires information and training that may not be available to department field staff when completing the PA form. While the type of aquifer cannot be practically considered in the field as part of the PA, it remains a factor to be considered in the final GWUDISW decision. The scores remain unchanged in the proposed Circular.

The proposed Circular removes the criterion for well cap construction. Questions about the well cap are now handled much more effectively by the Groundwater Rule, which was adopted after the last revision to PWS-5.

The proposed Circular modifies the PA determination by removing the pass/fail determinations. This is necessary to characterize the purpose of the PA more accurately—that is, a screening tool to help the department determine whether a source is ground water or needs further review.

Sources that score 40 or fewer points may be classified as ground water unless other information indicates that further review is necessary. The PA is not meant to be a final determination but is a tool intended to screen those sources that are easily classified as ground water. In other cases, a source may score less than 40 but may have some source- or site-specific information that warrants further review. Conversely, sources that score 40 or more points indicate a higher risk of surface water influence and warrant further review. The department may incorporate geologic maps, aquifer tests, nearby well logs, and other relevant information to understand the hydrogeology of the area and reach a determination.  If there is still uncertainty as to the direct surface water influence, then the department may require an MPA.

Sections 4.2 and 4.3 of the of the proposed Circular describe the MPA and the classification of sources. If the PA and other relevant information indicate a risk of surface water influence, the department may require an MPA. For the MPA to be a useful examination of potential surface water influence, the MPA must be completed under circumstances where surface water influence is most likely to occur. Such variables include, for example, the construction status of the source, the time of year, the operation of the test source and nearby sources, and the state of the nearby surface water.  

In these sections, the proposed Circular adopts procedures that differ from the existing circular in two significant ways. First, the existing circular requires that MPAs be conducted by the owner of the public water supply system. The proposed circular would put this requirement on the department. In developing the proposed Circular, one informal reviewer noted that the owner of each public water supply system should have the option to allow the department to complete the MPA or to do it themselves. Experience in administering PWS-5 has revealed that MPAs are often beyond the expertise and capabilities of the owners of the systems. Leaving this responsibility to the owners also creates the risk of introducing error in the collected samples and means that the department cannot verify that the sampling was done correctly. The department has conducted this sampling for the last several years.  This process has proven to reduce the burdens on the system owners, to result in more consistent sampling, and to provide more confidence in the final analytical result.  

The second significant proposed change would require that the MPA be the basis for classification for all sources with MPA results. The existing circular provides three methods for evaluating whether a groundwater source is under the direct influence of surface water: an MPA, a hydrogeologic assessment (HA), or a water quality assessment (WQA).  While the HA and WQA can address a hydraulic connection between surface water and ground water, they do not address whether surface water organisms can be and are being transported to the subsurface water. The MPA, on the other hand, is much more conclusive because it measures the occurrence of organisms whose presence in ground water can only be the result of direct influence of surface water.

The proposed Circular maintains the existing requirement that a water source with one or more moderate- or high-risk MPA results will be classified as GWUDISW, because such sources pose an increased risk to public health. In developing the proposed Circular, one informal reviewer encouraged the department to adopt an alternate methodology that, to the department's knowledge, has not been adopted by EPA or other states and would require significant reconsideration of other department rules and circulars. Because of that, the department decided to maintain the existing regulatory scheme and methodologies for this proposed rule update.

In developing the proposed Circular, DEQ considered conducting MPAs on proposed sources at the request of the system owner. DEQ has accommodated these requests in the past. After further consideration, DEQ removed proposed sources from the Circular. The final construction and operation of a source is unlikely to be identical as proposed, meaning that the MPA results for a proposed source may not be representative of the results of the final developed source.

The proposed Circular concludes with a section regarding the record of decision that the department issues for each water source, providing uniform notification to each system owner.

            Finally, the proposed changes to ARM 17.38.209 update the references to the statutory provision authorizing the department to conduct rulemaking and the statutory provision being implemented by adopting the proposed Circular. Updates to these references are necessary after the 2021 Legislature transferred rulemaking authority from the Board of Environmental Review to the department. Sec. 111, Ch. 324, L. 2021.


            4. The proposed changes to Circular DEQ-1 consist of inserting Table A-1, available as described in paragraph 5 below, into Appendix A, and as follows:


Circular DEQ-1: 3.2.2 Quality

The Department will determine, on a case-by-case basis, the minimum treatment required for a ground water source to ensure compliance with ARM Title 17, Chapter 38, Subchapter 2.

An assessment must be made of the factors, both natural and man-made, which may affect water quality in the well and aquifer.  Such an assessment may include obtaining samples over a sufficient period of time to assess the microbiological and physical characteristics of the water including dissolved gases and chemical and radiological characteristics.  A ground water under the direct influence of surface water determination assessment acceptable to MDEQ must be provided for all new wells. Approval of plans and specifications under this Circular is not a determination that a source is ground water for purposes of PWS-5 or the Surface Water Treatment Rule. Regardless of plan and specification approval, all sources must be evaluated by the Department pursuant to the requirements of PWS-5.


REASON: Circular DEQ-1, which provides engineering design standards for community public water supply systems, requires the applicant to provide information regarding the likelihood that a proposed source is GWUDIWS. As discussed elsewhere in this notice of proposed rulemaking, a final GWUDISW determination can only be made once the source is constructed and operating as intended. The proposed changes to Circular DEQ-1 clarify that all sources must be evaluated by the department pursuant to the requirements of PWS-5. This proposed change is not substantive and does not change any department procedures, but it does clarify the relationship between the two circulars. 

The department also proposes to reinsert Table A-1 into Appendix A of Circular DEQ-1. The 1996 Amendments to the Safe Drinking Water Act require primacy states to develop strategies to ensure the managerial, technical, and financial capacity for new public water supply systems. 42 U.S.C. § 300g-9. This capacity development strategy is also a required component for the department's ability to provide loan assistance to public water supply systems under the Drinking Water State Revolving Fund program. Id.; 42 U.S.C. § 300j-12. In 1999, as part of its state strategy, the department adopted Appendix A to Circulars DEQ-1 and DEQ-3, including a system budget table in Table A-1. This table summarizes a five-year projection of cash flow to properly operate and maintain the system. 

Table A-1 was included in Circular DEQ-1 until rulemaking conducted in 2006. The reasons for its omission in that rulemaking could not be ascertained. The department now proposes to reinsert the table into Circular DEQ-1. Experience in administering the circular has shown that submissions that do not use Table A-1 may lack continuity, completeness, and clarity. Reinserting the table would help ensure that the required technical, managerial, and financial components have been adequately addressed, would improve the capacity development process for the submitting project engineer and state review engineer, and would allow the department to meet its federal obligations under the Safe Drinking Water Act.


            5. A copy of the proposed Circular PWS-5 and Table A-1 may be viewed at the department's website using the following path: https://deq.mt.gov/News/publiccomment-folder/news-article.  Copies may also be obtained by contacting Jim Sutliff at (406) 444-0490, or Jim.Sutliff@mt.gov.


6. Concerned persons may submit their data, views, or arguments either orally or in writing at the hearing. Written data, views, or arguments may also be submitted to the Department of Environmental Quality, at 1520 E. Sixth Avenue, P.O. Box 200901, Helena, Montana 59620-0901; faxed to (406) 444-4386; or emailed to DEQGWUDISWRule2022@mt.gov, no later than 5:00 p.m., June 27, 2022. To be guaranteed consideration, mailed comments must be postmarked on or before that date.


7. Aaron Pettis, attorney for the department, has been designated to preside over and conduct this hearing.


8. The department maintains a list of interested persons who wish to receive notices of rulemaking actions proposed by this agency. Persons who wish to have their name added to the list shall make a written request that includes the name, e-mail, and mailing address of the person to receive notices and specifies for which program the person wishes to receive notices.  Notices will be sent by e-mail unless a mailing preference is noted in the request. Such written request may be mailed or delivered to the department or may be made by completing a request form at any rules hearing held by the department.


9. The bill sponsor contact requirements of 2-4-302, MCA, do not apply.


10. With regard to the requirements of 2-4-111, MCA, the department has determined that the proposed amendment to the above-stated rules and the proposed changes to PWS-5 and to Circular DEQ-1 will not significantly and directly impact small businesses. 



Reviewed by:                                               



/s/   Edward Hayes                                     /s/   Christopher Dorrington           

EDWARD HAYES                                      CHRISTOPHER DORRINGTON

Rule Reviewer                                            Director

                                                                    Department of Environmental Quality


Certified to the Secretary of State May 17, 2022.


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