Administrative Rules of the State of Montana

BEFORE THE DEPARTMENT OF ENVIRONMENTAL QUALITY

OF THE STATE OF MONTANA

In the matter of the amendment of

ARM 17.30.660 pertaining to nutrient standard variances

)

NOTICE OF AMENDMENT

(WATER QUALITY)

TO: All Concerned Persons

1. On April 14, 2017, the Department of Environmental Quality published MAR Notice No. 17-390 pertaining to the public hearing on proposed amendment of the above-referenced rule at page 394 of the 2017 Montana Administrative Register, Issue Number 7.

2. The department has amended ARM 17.30.660 exactly as proposed. However, the department has amended Circular DEQ-12B with modifications made in response to public comment as described below.

3. The department has thoroughly considered the comments received. A summary of the comments received and the department's responses are as follows:

COMMENT NO. 1: Department staff has worked hard in coordination with the Nutrient Work Group to complete the nutrient variance triennial review.

RESPONSE: The department appreciates the comment.

COMMENT NO. 2: For permit development, alternatives should be allowed in addition to a default coefficient of variation (CV) of 0.6, and clarification should be provided as to when it will be used.

RESPONSE: The department agrees that alternatives should be allowed in addition to a default coefficient of variation (CV) of 0.6. The department has modified the language in Circular DEQ-12B as follows: ". . . 0.6 must be used to determine . . ." has been replaced with ". . . 0.6 may be used to determine . . ." The department's intent was to assure that when wastewater facilities achieve low nutrient concentrations in their effluent, they would not have permit compliance issues due only to the often-observed high variability of nutrient concentrations when concentrations are low. This is especially true for total phosphorus (TP). Not all facilities have this concern today; however, this issue may become more important in the future as more facilities treat wastewater to levels approaching the limits of technology. The circumstances under which the department would apply the fixed CV can be determined on a case-by-case basis during permit development. For example, if a facility were completing an upgrade with a projected effluent TP concentration of 0.15 mg/L, it would be reasonable to apply the fixed CV in the permit as TP concentration variability would likely increase.

COMMENT NO. 3: The department's fixed coefficient of variation (CV) of 0.6 for permitting creates a less stringent highest attainable condition than would otherwise be enforced, in effect prioritizing discharger's concerns regarding treatment efficiency over the requirements of 40 CFR 131.14.

RESPONSE: The comment is technically correct, insofar as the fixed CV could in some cases provide a larger permitted load (however, in some cases, it could also result in a more stringent load). But it is important for the department to allow for the realities of wastewater nutrient removal; recognizing that the CV will likely increase as treatment approaches limits of technology. If a wastewater facility has improved treatment and is discharging low nutrient concentrations but also is facing the realities of sample variability, this should be given consideration. A key aspect of 40 CFR 131.14 is the highest attainable condition treatment requirement, which is determined via economic and technological capabilities; the CV is one aspect of the technological capability. See also response to COMMENT NO. 2.

COMMENT NO. 4: The proposed end-of-pipe treatment requirements in Table 12B-1 of Circular DEQ-12B were derived using very simplistic economic and technical analytical methods and have wide estimation ranges. Should the department be basing monthly average total nitrogen (TN) and TP treatment requirements on such methods?

RESPONSE: The department does not agree that the methods are "very simplistic." The methods follow Class 5 Engineering estimated costs per the Association for the Advancement of Cost Engineering (AACE) recommended practice No. 18R-97. These cost estimates were coupled with the department's long-established per-community cost threshold process, which identifies a community-by-community wastewater treatment cost cap for addressing nutrient standards. An accounting for collection system repairs was included. Further, engineers associated with the Nutrient Work Group carried out facility-specific cost estimates for almost all of the ≥1MGD facilities evaluated, providing somewhat better cost range estimates than Class 5. At the last full Nutrient Work Group meeting on March 27, 2017, the department asked engineers if, for the next triennial review, the department should use better cost estimates (say Class 2 or 3) since those have less error. The engineers expressed their best professional judgment that such estimates would be extremely expensive to complete (millions of dollars), as they require engineering projects to be defined to a very high degree. For these reasons, the methods used during this triennial review cannot be expected to be made substantially more precise.

COMMENT NO. 5: For some dischargers, their current/actual discharge concentrations may be the best attainable effluent, and in these situations a pollutant minimization program (PMP) applies and together (the achieved concentrations and the PMP) represent the highest attainable condition. The department should modify the language in Circular DEQ-12B Section 2.3 and elsewhere to make this clear.

RESPONSE: The department finds that the proposed Circular DEQ-12B is already sufficiently clear on this matter. Please see endnote 3 of Table 12B-1, which applies to permittees with mechanical facilities receiving a general variance in the ≥1MGD and <1MGD discharge categories. It is also clear in regards to the lagoon category within Table 12B-1. It is also specified in Section 3.1, paragraph two, in relation to individual variances. The department believes that no additional clarification is needed.

COMMENT NO. 6: Pollutant minimization programs (PMPs) are a new concept, need to be flexible, and permittees should be able to craft their own PMP (or have the PMP jointly reviewed by the permittee and the department) as opposed to having it imposed on them by the department. The department should clarify what constitutes approval of the PMP.

RESPONSE: The department agrees that PMPs need to be flexible. Circular DEQ-12B allows communities with mechanical facilities to examine different options and propose ideas to be implemented. The same is true for communities with lagoons. However, because of the unique challenges most lagoon systems face, the department will work with lagoons to assist in the development of individual lagoon-specific PMPs. Prior to the completion of this step, the department has adopted a basic framework PMP to ensure the individual PMPs are carefully tailored. This approach provides needed flexibility for lagoon facilities. Additional clarity regarding PMP approval was added to DEQ-12B. See also response to COMMENT NO. 17.

COMMENT NO. 7: Approval of pollutant minimization programs (PMPs) by the department should not be required. Compliance with the highest attainable condition constitutes the only enforceable standard.

RESPONSE: See response to COMMENT NO. 57.

COMMENT NO. 8: Language in Section 3.1 of draft Circular DEQ-12B suggests that the pollutant minimization program (PMP) will be required instantly. We recommend that permittees be given six months to develop and submit a PMP following notification by the department that a PMP is needed.

RESPONSE: In the case of an individual variance, a pollutant minimization program (PMP) would not be required at the time the variance was granted (i.e., at the time the permit was issued, renewed, or modified) unless the permittee is already achieving the highest attainable condition (HAC). As an eligible permittee begins to approach the established HAC treatment requirements, there should be adequate time and opportunity to prepare and submit a PMP. If a permittee is already treating its effluent to a level that will achieve the anticipated HAC treatment requirements, there should be adequate time and opportunity to prepare and submit a PMP during the individual variance development process.

COMMENT NO. 9: Wording in Endnote 3 of draft Circular DEQ-12B suggests a duplicative search of current and future technologies already completed by the department as part of its triennial review. The endnote should be simplified to indicate that facilities meeting Table 12B-1 values must continue to do so, and implement a pollutant minimization program (PMP).

RESPONSE: The department does not expect a duplicative additional search and analysis of candidate technologies. The department made the change as recommended in the comment letter. The modification makes sense and is consistent with the intent of the endnote—which is to clarify that group members who are doing better than the requirements in Table 12B-1 must continue to do so (and, in addition, develop a pollutant minimization program during their next permit cycle). See also response to COMMENT NO. 30.

COMMENT NO. 10: Draft Circular DEQ-12B, Section 3.1, paragraph two, sentence three: The department should strike out the word "application."

RESPONSE: The department agrees with the comment and made the change in the final circular.

COMMENT NO. 11: The department should provide references or cite factual information to support statements made in Sections 2.0 and 6.0 in its technical support document "First Triennial Review of Base Numeric Nutrient Standards and Variances."

RESPONSE: Section 2.0 of the technical support document addressed advances in nutrient removal. The Water Environment Federation publication "The Road towards Smarter Nutrient Management in Municipal Water Treatment" (2014) appears to be the most recent national-level publication on this issue. The report addresses areas of future exploration that are already in the process of implementation in Montana, most notably, process control changes to enhance nutrient removal and regulatory innovation with respect to nutrients, of which this proposed nutrient variance and seasonal nutrient permits are examples. Technologically speaking, the innovative focus was on nutrient recovery, urine separation, water conservation, and further assessment of nitrogen and phosphorous treatment alternatives. There was no identification of any breakthrough treatment methodologies for nutrients that weren't already considered in 2014. Section 6.0 of the technical support document addressed the development and establishment of the highest attainable condition (HAC). The Tetra Tech memorandum "State of Montana Wastewater System Nutrient Reduction Cost Estimates" (2016) established a stepped approach that proposed certain treatment technologies for various levels of effluent quality for each parameter. However, on any given project, consulting engineers vary considerably on their chosen technical alternative and on their estimate of effluent quality. Within the Nutrient Work Group, consulting engineers, municipal public works directors, and department engineers contributed opinions or best professional judgement regarding seasonal effluent quality, likely effluent limitations, operator qualifications and availability, and estimated project cost based on years of experience of design and operations in Montana. The application of advanced operational strategies, while highly successful in some cases, has yet to be fully implemented in Montana, and very sporadically implemented nationally, for designed biological nutrient removal (BNR) treatment facilities. Because each treatment system is unique with regard to the application of advanced operational strategies, at this time there is no general reference available that predicts effluent quality improvement. Therefore, the values proposed for HAC are a compilation of best professional judgments from department engineers as well as other professional engineers within the Nutrient Work Group, which take into account the several factors mentioned above.

COMMENT NO. 12: In the department's first triennial review technical support document, the department appears to be comparing the average of 95th percentile of effluent data (a measure of the upper tail of the distribution of effluent data) with the State's proposed highest attainable condition (HAC) values expressed as a monthly average (a measure of the central tendency). Because the HAC limits are expressed as a monthly average, we recommend the department compare the State's proposed HAC values to the 95th percentile of monthly averages of effluent data from other facilities.

RESPONSE: The department has carried out the calculation recommended by the commenter on the facilities shown in Table 6-1 of "First Triennial Review of Base Numeric Nutrient Standards and Variances" (Water Quality Planning Bureau, 2017). The results indicate the 95th percentile of the publicly owned treatment works' (POTW) long term averages is 6.3 mg TN/L and 0.56 mg TP/L (for the latter, Butte's TP data was excluded). These results support the idea that the proposed general variance treatment requirements for the ≥1MGD group are largely in line with what is achieved nationally by other major POTWs that are addressing nutrients.

COMMENT NO. 13: The department should include reference to reverse osmosis (RO) in the final version of DEQ-12B to avoid contradictions with the State's substantial and widespread economic analysis in its technical support document, which is based on RO.

RESPONSE: The department has consistently viewed reverse osmosis (RO) as the best available technology to get as close to the base numeric nutrient standards as possible, in the absence of dilution. The department's statewide economic impact analyses in 2012, 2014, and today are all based on the estimated cost of installing and operating RO treatment; the findings are all in the record (e.g., "Demonstration of Substantial and Widespread Economic Impacts to Montana That Would Result if Base Numeric Nutrient Standards had to be Met in 2011/2012" (Blend and Suplee, 2012). The department has consistently referenced RO throughout its variance process and does not believe it is necessary to also include reference to it in the circular.

COMMENT NO. 14: The department should review for accuracy the list of facilities (including lagoons) likely to need a nutrient standards variance, and incorporate that list (or make reference to it) in the rule.

RESPONSE: The department agrees with the comment, and has included a reference to a list of facilities (including lagoons) in Section 2.0 of Circular DEQ-12B.

COMMENT NO. 15: The department should clarify that the term "triennial review" in the context of nutrient standards and variances refers to the reevaluation of the variance consistent with federal requirements at 40 CFR 131.14(b)(1)(v). Further, the department should clarify the time interval in which the next review of the variances (both individual and general) will occur after EPA approval of the previous review.

RESPONSE: The department has consistently used the term "triennial review" when referring to the requirement in state statute (at 75-5-313(7)(a), MCA) to carry out a review of the variance treatment requirements every three years. So far, the department has reviewed the base numeric nutrient standards (in Circular DEQ-12A) at the same time as the variance rules. Together, the department's review of the nutrient standards and variances is consistent with the Clean Water Act requirement to review water quality standards every three years. With the federal regulation changes that occurred in 2015 (40 CFR 131.14(b)(1)(v)), water quality standards variances are now required to be reviewed no less frequently than every five years. The department clarifies here that the triennial review, in the context of nutrient variances, refers to and is consistent with 40 CFR 131.14(b)(1)(v). Regarding the specific steps in the time interval, the department will review the nutrient variance circular (DEQ-12B) within three years of EPA approval of the previous version, and complete any necessary rulemaking within one year of finishing its review.

COMMENT NO. 16: The department should clarify the specific term (in years) of the general variance following EPA approval.

RESPONSE: The term of the variance is up to 17 years, as indicated in Table 12B-2. The department modified Section 2.1 of the circular to further clarify that the time of the variance must be as short as possible but up to 17 years.

COMMENT NO. 17: The department should clarify the reason for the timeframe (in years) needed for the lagoon PMPs to be implemented.

RESPONSE: The draft Circular DEQ-12B states that the department and permittee shall complete the lagoon optimization/pollutant minimization program no later than 7/1/2027. This ten year time period is necessary to complete the program because the program is a hybrid of department and permittee actions. This year (2017), the department is starting a full municipal-scale test of an innovative technology to improve lagoon wastewater effluent quality. The department will very likely carry out another test at another facility; it may also test another innovative technology. The department will need time to analyze the results, prepare reports, and make recommendations. This will take several years—probably more. The department will also conduct a statewide review of lagoon performance (e.g., is sludge removal in order). The number of facilities that can be reviewed each year is limited, and again, this will take time (estimated to 2022). Permittees with lagoon systems must provide information to the department related to optimization/pollutant minimization program activities they identify. These will be case-specific and the department needs time to evaluate them and provide feedback. Again, this takes time. Altogether, these actions could very realistically span over ten years, which is the time period the department proposed for their completion.

COMMENT NO. 18: The department should provide an update to Table 2-1 of "Economic Analysis of Meeting Base Numeric Nutrient Standards: Supplement to First Triennial Review of Base Numeric Nutrient Standards and Variances" (April 28, 2017) which includes each community's secondary score.

RESPONSE: The department considered secondary scores in its analysis. The secondary scores were calculated using the latest economic data, and confirmed significant impact for almost all towns. They have been included in the table shown below, as requested (2nd column from right), along with the associated % MHI cost cap which are derived from the secondary scores (see last column on right). Table 2-1 below may also be found at http://deq.mt.gov/Portals/112/Water/WQPB/Standards/NutrientWorkGroup/PDFs/Comment18Table.pdf.

COMMENT NO. 19: The department should provide additional information describing the basis for concluding, in the first triennial review technical support document, that Helena will demonstrate substantial and widespread economic impacts.

RESPONSE: As noted in the table provided in the response to COMMENT NO. 18 above, Helena's MHI screener and secondary score (columns four and two, respectively, from the right) places them on the borderline for a "Significant" finding per 1995 EPA guidance for an individual variance. This means that Helena moves on to a "Widespread" impact investigation. Helena would need to almost triple their wastewater rates to customers to get to reverse osmosis (RO), and this would lead to less disposable income for all residents, a concurrent decrease in local business, and would hit poverty level households the hardest. This constitutes widespread economic impact.

COMMENT NO. 20: The department should explain why there are different sets of lagoons examined in the technical support document "First Triennial Review of Base Numeric Nutrient Standards and Variances" (Water Quality Planning Bureau, 2017). In Table 3-1 of Section 3.0 (Statewide Economic Impact Demonstration), six lagoons are included, whereas the cost-per-treatment-level analysis for the lagoon category was carried out on eight different lagoons (Figure 6‑3 of Section 6.0).

RESPONSE: The department agrees that there are two different lists of lagoon-based communities (but notes that there is one community common to both, Highwood). The lagoon-based communities in Table 3-1 are part of a larger group of Montana communities the department has been tracking since 2011 for the purpose of evaluating the cost to meet base numeric nutrients standards via reverse osmosis. In contrast, the eight lagoons in Figure 6-3 were randomly selected in order to provide an unbiased sample of lagoon-based communities for which the department could calculate the cost for different treatment levels and identify highest attainable condition (HAC). Because the sample was random, the results should be representative of the cost to achieve HAC for lagoon-based Montana communities.

COMMENT NO. 21: The department should review the private sector dischargers' information to further support the need for the variance and review existing wastewater treatment systems and effluent data to evaluate whether these limits actually reflect the highest attainable effluent condition for these facilities and include this evaluation and rationale in the documentation that will be submitted to EPA.

RESPONSE: The department has taken a close look at the private sector dischargers likely to need a variance (for a list of private-sector permittees, see Appendix A of "First Triennial Review of Base Numeric Nutrient Standards and Variances" (Water Quality Planning Bureau, 2017)). Case-specific circumstances show that: 1) many will probably not in fact need a variance; 2) their eligibility for one is clear; and/or 3) they have already been issued a general variance. In the ≥1MGD category, Philips 66 stopped discharging to the Yellowstone River on June 1, 2014, and since that time their treated process water has gone to the Billings WWTF. In the <1MGD category, Drumlummon Gold Corporation has closed and shut off its pumps; there is no discharge. The Stillwater Mine on the East Boulder River has a Good Neighbor Agreement which has been a successful arrangement between the mine, environmental groups, and local citizens, and assures environmental protection beyond the MPDES permit. The Stillwater Mine has already been issued a general variance. Elkhorn Health and Rehabilitation (permitted under Apple Rehab West, LLC) is a very small company that would undoubtedly be incapable of affording to meet the base numeric nutrient standards. Similarly, Montana Behavioral Clinic is a small non-profit 501 (c)(3) corporation and would be very unlikely to meet the base numeric nutrient standards. Bonner Property Development operates a small industrial park and was already issued a general variance, as was Barretts Minerals Inc.

COMMENT NO. 22: The commenters continue to be concerned about the adoption and implementation of numeric nutrient standards at levels below what viable treatment technology can achieve, and that Montana has adopted these standards in advance of most other states.

RESPONSE: The department is aware of this concern. It was also expressed during the 2014 adoption of the base numeric nutrient standards and variances. However, the variance process remains the most viable approach to achieving the standards over time, allowing time for technologies to advance and costs to come down, and for nonpoint source nutrient issues to be addressed.

COMMENT NO. 23: There is nothing in the record indicating that any particular wastewater N:P ratio should be maintained and, depending on background conditions, similar effluent ratios may lead to varying N:P ratios in receiving waters.

RESPONSE: The department agrees that the statement is generally true. However, there is nothing that suggests the N:P ratios we have selected are inappropriate. As it stands, the proposed general variance treatment requirements result in wastewater N:P ratios of 20:1 and 15:1 (by weight) for the ≥1MGD and <1MGD groups, respectively. Although at wastewater-strength concentration or in the immediate mixing zone no nutrient limitation would occur, if these ratios were maintained and sufficiently diluted downstream of a facility they would result in P-limitation. Individual variances may have effluent N:P ratios different from these, depending on site specific considerations. But customizing effluent N:P ratios within the general variance treatment requirements is unnecessary and would not further serve the department's dual-nutrient control policy. No change was made to the circular in response to this comment.

COMMENT NO. 24: The department has made no demonstration in the current rulemaking process that lowering of nitrogen and phosphorus to the proposed treatment levels will improve or benefit water quality.

RESPONSE: The department has already provided this information. For example, in Section 11.3.5 of "Using a Computer Water Quality Model to Derive Numeric Nutrient Criteria: Lower Yellowstone River, MT" (Flynn and Suplee, 2013), modeling results show a large increase in nitrogen and phosphorus concentrations below and due to the Billings WWTP, especially phosphorus, with effects all the way down to the Big Horn River confluence. This reach of the Yellowstone River has been rendered nitrogen limited because of the high availability of phosphorus from the WWTP. The N:P ratio of nutrients per the general variance for the ≥1MGD group (which includes Billings) is 20:1 (by weight), and leans well towards phosphorus limitation. Although concentrations in the immediate zone below the WWTP may not see improvements at the proposed general variance concentrations (6 mg TN/L and 0.3 mg TP/L) because concentrations are too high, further dilution downstream should lead to dozens of kilometers of improved water quality in the reach. Similar findings are documented in the department's whole-stream nutrient addition study ("Whole-stream Nitrogen and Phosphorus Addition Study to Identify Eutrophication Effects in a Wadeable Prairie Stream", Suplee et al., 2016). There, excess nutrients from the high-dose reach (which was dosed to 0.12 mg NO₃-N/L and 0.016 mg SRP/L) continued to impact algal levels for kilometers downstream of the dosing site. In contrast, effects below the low-dose reach (dosed to 0.04 mg NO₃-N/L and 0.004 mg SRP/L) were non-existent 0.9 km downstream. In short, reduction in nutrient concentrations from point sources can and will result in improved water quality at some point downstream of wastewater treatment plants (WWTPs); in some cases this may results in many miles of improved waterways. Both reports can be found at http://deq.mt.gov/Water/WQPB/standards/numericnutrientcriteria.

COMMENT NO. 25: The record indicates that many Montana waters would benefit from reductions of nitrogen and phosphorus in many cases.

RESPONSE: The department agrees with the comment, and in its response to COMMENT NO. 24 points to two published reports in which such documentation can be found.

COMMENT NO. 26: The proposed rule changes will increase the cost of centralized wastewater treatment, forcing rate payers to relocate to rural areas and thereby increasing the non-point source component of nutrient pollution.

RESPONSE: The department does not agree with the comment. In 2008 the department prepared estimates of the total cost for a homeowner to operate a home septic system; costs included initial installation, maintenance, pump-out, electricity, etc., and were amortized over the life expectancy of each system component. Estimates were made, from least to most expensive, for (1) a standard septic system, (2) a standard septic system in a maintenance district, (3) an unmaintained septic system, and (4) a level 2 wastewater system. Adjusted for inflation, the per-household costs range (in 2017 dollars) from $31 to $96 per month, depending on the system installed. As part of this triennial review, the department calculated—for communities likely to need a variance, and which use a centralized wastewater system—the maximum wastewater cost that community members would be expected to pay towards meeting nutrient standards. Communities included Helena, East Helena, Conrad, and Billings. The department's method is based on community-specific economics and median household income (see page 14 of "First Triennial Review of Base Numeric Nutrient Standards and Variances"). The per-household cost among the assessed communities ranged from $30 to $119 per month, with a community group average of $60/month. These data indicate that the department's actions per this rulemaking would not increase centralized wastewater costs to the point that they would force community members into rural areas, because the per-household costs are actually similar. Beyond this, the 2010 census showed that the continued and long-standing trend in Montana is that of people moving from rural to urban areas, not the other way around.

COMMENT NO. 27: The proposed wastewater treatment requirements in Table 12B-1 of Circular DEQ-12B do not reflect the highest attainable condition. A combination of biological nutrient removal, filters, and chemical additives have allowed other wastewater treatment plants to achieve far lower concentrations than the proposed requirements of—for the ≥1MGD group—6 mg TN/L and 0.3 mg TP/L.

RESPONSE: The department does not agree with the comment. The department believes that the analyses presented support the proposed wastewater treatment requirements in Table 12B-1 of Circular DEQ-12B, and that they do reflect the highest attainable condition (HAC). The department is aware that the technologies and combinations thereof cited by the commenter can achieve effluent with lower nutrient concentrations. As part of its analysis, the department evaluated treatment levels all the way down to the limits of technology for the ≥1MGD discharger group (see Figure 6-2 in "First Triennial Review of Base Numeric Nutrient Standards and Variances" (Water Quality Planning Bureau, 2017)). But HAC is not selected by adopting the very best wastewater technology, regardless of cost; it is determined by considering technology and the cost to implement the technology. Montana median household income is in the bottom four fifths among U.S. states, and affordability is scaled accordingly. For the ≥1MGD group—comprised almost exclusively of POTWs—the cost for each treatment level in Figure 6-2 was computed for each facility and compared to the department's affordability criteria. 7 mg TN/L and 0.5 mg TP/L was affordable for the majority of members, but at stricter treatment levels as few as 50% of members could afford the level. The final department recommendation (6 mg TN/L, 0.3 mg TP/L) reflect HAC for the majority of members in the ≥1MGD group.

COMMENT NO. 28: The proposed wastewater treatment requirements Table 12B-1 of Circular DEQ-12B should be set at the lowest effluent concentrations facilities in the category can afford, instead of being set at what is affordable for the majority of facilities, as the department has done. Facilities that cannot afford to achieve these more stringent concentrations could apply for an individual variance.

RESPONSE: The comment minimizes the difficulty in determining exactly what the group's lowest affordable effluent concentration is. If the department were to set the affordability limit to that of the most affluent community in the group, all remaining group members would be required to move to individual variances which would defeat the needed utility of a group general variance. The department has selected a highest attainable condition based on affordability of a simple majority, a straight-forward and commonly understood benchmark for evaluating factors that affect groups. It is reasonable that if the majority of group members cannot afford something, then it is not affordable for the group. At the treatment levels proposed by the department, all wastewater dischargers under the general variance will be required to improve their treatment, be that via stricter general variance limits or via current performance plus the optimization/pollutant minimization program. See also, response to COMMENT NO. 50.

COMMENT NO. 29: Capping permittee's discharge limits at previous performance levels as described in the rule amendments penalizes permittees for outstanding performance and is not in line with any current cited rule or statute.

RESPONSE: Since adoption of the base nutrient standards and variances in 2014, the department has consistently established dischargers' permit limits for general variances at previous performance levels when those levels were better than the requirements in Table 12B-1 of Circular DEQ-12B. This is consistent with department rule, as found in paragraph two of Section 2.0 of the July 2014 edition of Circular DEQ-12B. There, it is explained that the treatment levels described in 75-5-313(5)(b) (and found in Table 12B-1) were minimum treatment levels. Therefore, with the overarching goal of decreasing nutrient concentrations in wastewater effluent, the department's permitting unit has consistently established dischargers' permit limits for general variances at previous/existing performance, for those cases where the permittee needs a variance.

COMMENT NO 30: The department's expression of the highest attainable condition (HAC) for permittees already achieving more stringent effluent concentrations than the proposed HAC values in Table 12B-1 is ambiguous. The department should explicitly specify that where actual effluent concentrations are lower (i.e., better) than the HAC values for either one or both nutrients in Table

12B-1, then these dischargers must meet the current effluent concentration for one or both nutrients and implement a pollutant minimization program (PMP).

RESPONSE: The department finds that the proposed Circular DEQ-12B is already sufficiently clear in this matter. Endnote 3 of Table 12B-1 pertains to the ≥1MGD and <1MGD groups, the groups for which group highest attainable condition (HAC) concentrations are provided. (Lagoons are a group too, but are to maintain their case-by-case current performance.) Endnote 3 clarifies that facilities that are already meeting (or by extension, doing better than) the requirements in Table 12B-1 for one or both nutrients and have shown that no additional feasible pollution control technology can be identified must continue to meet those levels, and develop an optimization/pollutant minimization program. See also section 2.0, paragraph 3 of Circular DEQ-12B and response to COMMENT NO. 31.

COMMENT NO. 31: Circular DEQ-12B, Section 2.0, paragraph three. This paragraph should be re-written to indicate that, for permittees whose permits renew after July 1, 2017, the proposed Table 12B-1 treatment requirements must be used to establish the permit limit, in lieu of their actual attained effluent level (if those levels are better than—i.e., at a lower concentration than—the table values).

RESPONSE: The department does not agree with the comment. The purpose of the date separation is to identify those facilities in each discharger group that already have—affordably—met the treatment requirements in Table 12B-1. This will assure that their permit limits continue to reflect what they have already accomplished. The department will examine the 95th percentile of each facility's average monthly nutrient concentrations in order to make this distinction. For those group members that have yet to achieve the proposed limits, the department's proposed highest attainable conditions in Table 12B-1 establish the limits that are affordable to the majority of group members.

COMMENT NO. 32: Circular DEQ-12B, Section 2.0, paragraph three. The department's reference to actual concentrations "calculated as the 95th percentile of representative effluent data" is confusing. It is recommended that the department use the 95th percentile of the monthly average concentrations represented over a two year period.

RESPONSE: The department agrees that the paragraph is written in an ambiguous way and has rewritten the paragraph for clarity. The intent was to be able to make a distinction between permittees who have been consistently doing better than the proposed treatment requirements in Table 12B-1, and those that were not. Going forward, the department will use the 95th percentile of representative monthly average concentrations; the exact timeframe over which these data will be used will be left to the discretion of the permit writer, who will be most familiar with the status and recent changes (if any) at each facility.

COMMENT NO. 33: The department appears to intend to apply the general variance to permittees in the future once numeric nutrient criteria are adopted for waters into which these permittees are discharging, so it is recommended that language be included in DEQ-12B that would facilitate the understanding of how additional dischargers are eligible for the general variance.

RESPONSE: The department is working on numeric nutrient standards for additional large river segments (Yellowstone, Missouri) and may develop other nutrient standards as well. Over time, these criteria will be completed and proposed to the Board of Environmental Review for adoption into department Circular DEQ-12A. After nutrient criteria are adopted as standards, there may be dischargers along the affected waterways that need a nutrient standards variance. They will be able to apply for a variance at the time that they need one, after adoption, just as permittees on waterways with already-adopted nutrient standards can do so now. No clarifying language in the rule or circular is necessary.

COMMENT NO. 34: The department has not demonstrated that the advanced treatment technologies required to meet the highest attainable conditions are either cost effective or efficient; this should be done using specific, department-defined methods in the planning process for preparing preliminary engineering reports.

RESPONSE: While there is no requirement in Circular DEQ-2 (containing the department's requirements for preliminary engineering reports) for evaluating cost-effectiveness or efficiency, there is a requirement to prepare a cost estimate for the selected alternative and for comparing costs between alternatives based on accepted engineering economic practices. However, there is a requirement in the Water, Wastewater and Solid Waste Action Coordinating Team (WWASACT) Preliminary Engineering Report checklist that pertains to "Cost and Effectiveness" that addresses water conservation and energy efficiency, however, that requirement is only applied to the comparison of alternatives in the planning stage of a project.

COMMENT NO. 35: The City of Helena is being penalized for being progressive in its optimization efforts prior to this new permit.

RESPONSE: The department does not agree with the comment. The City of Helena's permit will be handled in the same manner as other communities statewide, including other communities that have also instituted optimization work in the past few years. While the department commends Helena for its previous optimization efforts, the department's analysis indicates that the improvements Helena has made in effluent nitrogen concentrations still result in levels above the proposed highest attainable condition treatment level of 6 mg TN/L; thus, viewed from this perspective, Helena still has some additional work to do in order to achieve the proposed limit.

COMMENT NO. 36: Better, more innovative wastewater treatment options are available, but were not thoroughly considered. The department needs to "think outside the box" and aggressively pursue and implement novel technologies and management techniques capable of significant pollutant reductions, rather than spending finite energy, time, and resources towards meeting minimal pollutant reductions.

RESPONSE: The department is in fact monitoring advances in innovative wastewater treatment, for example anaerobic ammonium oxidation (ANAMMOX). The WERF (Water Environment & Reuse Foundation) study on full-scale application of ANAMMOX is still under way, but is likely to have yielded findings by the next triennial review. Regarding "thinking outside the box" and aggressively implementing novel technologies and management techniques, the department believes it is promoting the concepts and approaches the commenter is referring to. For example, the department has promoted advanced operational strategies at eleven WWTPs over the past five years, yielding quite a few success stories in terms of very large reductions in effluent nutrient concentrations for little cost. See 2016 report (accessed June 6, 2017) at http://www.cleanwaterops.com/wp-content/uploads/2016/02/Montana-Report-Final-Proof.compressed.pdf. Similarly, this year (2017), the department is financing the first full-scale application of an innovative technology (constructed floating islands) in a wastewater lagoon to be carried out in this climatic zone (continental northern temperate). The department will be carefully monitoring the wastewater treatment enhancements resulting from this application, to determine if the technology can be recommended to other Montana communities using wastewater lagoons. Should these concepts and approaches prove both successful and feasible, the department will strongly consider future implementation.

COMMENT NO. 37: Linking nitrogen and phosphorus treatment together under the general variance with technology based effluent limits fails to recognize that water quality objectives may be attained without the need to treat for both to the same extent.

RESPONSE: The department has long maintained a dual-nutrient control policy for nitrogen and phosphorus. This overarching approach is supported by the department's own scientific and technical work and is consistent with EPA recommendations. At the same time, the department recognizes that emphasis on one nutrient over the other may achieve the same water quality goals in some locations. If such findings are appropriately modeled and sufficiently documented, they can form the basis of an individual variance as described in ARM 17.30.660(4).

COMMENT NO. 38: Refractory dissolved organic compounds in effluent should be given consideration in light of achieving the proposed effluent limits of 6.0 mg TN/L and 0.3 mg TP/L.

RESPONSE: The department does not agree that these compounds should be given consideration at the proposed treatment levels (6.0 mg TN/L and 0.3 mg TP/L). As the commenter points out, refractory compounds are really an issue when treatment requirements are close to the limits of wastewater technology, which the proposed limits are not. The department does agree that refractory compounds should probably be given consideration if treatment requirements were to drop close to the limits of wastewater technology; the department stated this during deliberations of the Nutrient Work Group in advance of the original rule adoptions in 2014, and confirms it again here. The department will continue to monitor the science and technology of the refractory compound issue.

COMMENT NO. 39: The department should leave the interim wastewater treatment requirements as they are found in the 2014 version of Circular DEQ-12B.

RESPONSE: Based upon the department's required review of the general variance under 75-5-313(7), MCA, consultation with the nutrient work group, and the need to comply with updated federal requirements at 40 CFR 131.14, the department must update the wastewater treatment requirements. No change was made to the circular as a result of this comment.

COMMENT NO. 40: Twenty year variance terms are longer than necessary to meet highest attainable conditions.

RESPONSE: Wastewater treatment upgrades can be very expensive and take significant time to design, obtain funding for, construct, and optimize in order to meet the highest attainable condition (HAC). Circular DEQ-12B and the technical justification describe the nine potential steps and approximate time periods for each step, up to 17 years, that could be necessary for a discharger to comply with the HAC values.

COMMENT NO. 41: Highest attainable condition values set in this rulemaking will directly affect once-in-a-generation investments of communities making wastewater treatment upgrades. There are large differences in technology upgrades to achieve 3-5 mg TN/L vs. 6-10 mg TN/L, and it is extremely unlikely that dischargers will make more than one facility upgrade in a generation, which is to say the remaining 17 years in Montana's variance framework.

RESPONSE: Circular DEQ-12B and the technical justification describe nine steps that a discharger may need to take in order to achieve the highest attainable condition (HAC) values. Those steps include two potential capital improvement projects. The first step could be a major capital improvement project, with a potential smaller capital improvement project later, if necessary. Thus, the department does not agree that investments made in wastewater facilities will be limited to only once within the remaining variance period.

COMMENT NO. 42: It is our opinion that the Nutrient Work Group technical subcommittee did not reach consensus regarding the proposed highest attainable condition.

RESPONSE: The department hosted five meetings and provided a memo to the Nutrient Work Group (dated March 17, 2017) stating the overall findings and recommended highest attainable condition ranges resulting from these consultations. The department agrees that there were individuals at that time who felt a consensus was not achieved, and stated so in the memo.

COMMENT NO 43: The department has made no substantial progress in addressing non-point sources of nitrogen and phosphorus; addressing the nutrient pollution problem needs to be much more equitable between point and non-point sources.

RESPONSE: The department recognizes the impacts that nonpoint sources have on nutrient pollution. In addition to the work that the department's Nonpoint Source Program does annually, the department is working on developing a plan to coordinate its nonpoint source work and investments in order to leverage and reinforce the investments made by discharges to achieve point source treatment improvements.

COMMENT NO 44: 40 CFR 131.14 requires identification and documentation of cost-effective and reasonable non-point source controls for nitrogen and phosphorus. The 2017 draft rule does not address this requirement.

RESPONSE: The 40 CFR 131.14 requirements to identify and document any cost-effective and reasonable best management practices for related non-point source controls pertain to variances that apply to a waterbody. The department is adopting variances that are discharger-specific, not waterbody specific, thus that requirement does not pertain. However, the department recognizes the impact of non-point source pollution and is addressing it via its Montana Nonpoint Source Management Plan. In addition to Montana's Nonpoint Source Management Plan, the department has adopted nutrient trading rules in Circular DEQ-13 that apply to any water body or waterbody segments where a variance could be implemented. The purpose of Circular DEQ-13 is to facilitate cost-effective and reasonable reductions in nutrients.

COMMENT NO. 45: To meet the treatment requirements in the new rules, communities will have to divert money from other projects, such as wastewater conveyance (collection system) maintenance, and school and road repairs; the public's willingness to pay will be exceeded resulting in a further downward spiral in deferred maintenance.

RESPONSE: Circular DEQ-12B, department rules, and associated guidance all take into account the economic health of communities and their ability to affordably achieve the highest attainable condition values, through an analysis of median household income and secondary scores. If a discharger determines that they cannot afford the treatment requirements Circular DEQ-12B then they may seek an individual variance.

COMMENT NO. 46: The department should not consider the cost of collection system upgrades in making its economic hardship demonstration or in determining highest attainable condition values.

RESPONSE: The department, working with the Nutrient Work Group technical subcommittee, developed a conservative cost factor for collection system upgrades in order to reflect the impact that those costs will have on wastewater fees and subsequently on the ability of dischargers to afford to meet the proposed wastewater treatment levels. See also response to COMMENT NO. 47.

COMMENT NO. 47: The department should elaborate on why all dischargers eligible for the general variance will need to include the cost of collection system upgrades.

RESPONSE: The Tetra Tech memorandum "State of Montana Wastewater System Nutrient Reduction Cost Estimates" (2016) did not take into account the cost associated with future collection system upgrades. Based on information gathered during Nutrient Work Group meetings, current wastewater fees often do not cover or only cover a small fraction of needed collection system repairs. These costs will raise future wastewater fees and impact the ability of dischargers to afford to meet different treatment levels. The department concluded it was reasonable to include some consideration of this future expense all communities will ultimately have to deal with.

COMMENT NO. 48: We support the continued maintenance of general variance groups based on discharge volume, as was originally established in statute and as remains intact in the proposed rules.

RESPONSE: The department agrees with the comment.

COMMENT NO. 49: The general variance approach conflicts with Clean Water Act requirements. The department should revise its 2017 variance rules to reflect an individualized variance process to assure compliance with customized, appropriately-stringent highest attainable conditions.

RESPONSE: The federal rule changes of 2015 allow for multiple discharger variances (which are equivalent to Montana's general nutrient standards variance). In the preamble to the Federal Register notice announcing the 40 CFR 131.14 water quality standards variances rules, see Fed. Reg. 51020, 51036 (August 21, 2015), EPA states that "States and authorized tribes may adopt WQS variances for a single discharger, multiple discharges, or a water body or waterbody segment . . ." The department (consistent with state statute) uses discharge volume or whether a facility is a lagoon or not as its multiple-discharger eligibility requirement. See also response to COMMENT NO. 14.

COMMENT NO. 50: There are not that many facilities in either the ≥1MGD or <1MGD categories, so the department should simply establish facility-by-facility highest attainable conditions rather than developing categorical HACs.

RESPONSE: Section 75-5-313(5)(b), MCA, requires the department to establish general nutrient standards variances for these discharge groups. At this time only six POTW facilities in the <1MGD group and 10 facilities in the ≥1MGD group will need general variances. The highest attainable condition (HAC) is set as a categorical value for each of the three groups (the third being lagoons), but how the variance is implemented and expressed in a permit will be different for each discharger based on group HAC levels, current performance, current permit treatment limits, receiving stream standards, economic health of the community or business, current treatment systems and technology, and optimization plans and implementation. Based on the analysis required under 40 CFR 131.14, the new Circular DEQ-12B represents a 40-60% decrease in group nutrient treatment levels for the ≥1MGD and <1 MGD groups over the existing nutrient treatment levels in the circular. Over the life of the variance, the rules will require that every discharger who needs a nutrient variance improve nutrient treatment for both TN and TP in one or more of the following ways: 1) dischargers who are currently at or below HAC for TN and TP will have their treatment levels capped at current performance; 2) once a discharge meets or exceeds (i.e., does better than) HAC for either TN or TP, they will be required to develop an optimization/pollutant minimization program which will result in further improvement over their existing treatment levels; 3) dischargers who have not yet achieved HAC will be required to do so as soon as they can, not to exceed the 17 years remaining in the life of the variance; 4) dischargers who have permits with treatment levels below HAC will have their treatment levels capped at the level of their current permits as a result of anti-backsliding and will have to develop an optimization/pollutant minimization program to bring treatment levels down; and 5) if a discharger cannot afford the group variance then they can seek an individual variance which will individualize the HAC and the timeline to achieve it. Here are four examples of how the general variance values will be expressed differently depending upon the facility and will result in decreased treatment levels in all cases.

Community A has an existing permit average monthly load limit set at 241 lb/day TN which is lower (more restrictive) than the group HAC treatment requirement in Circular DEQ-12B because of the lake located directly downstream of their outfall. As a result, Community A will be capped at their current permit load of 241 lb/day TN due to anti-backsliding requirements, and also be required to develop an optimization/pollutant minimization program. For TP, Community A will be required to improve their treatment levels from the current average monthly load limit of 108 lb/day TP to approximately 23 lb/day TP under the HAC treatment requirements in Circular DEQ-12B.

Community B will be capped at TN and TP current performance because they have already been treating their effluent to concentrations lower than (better than) the HAC treatment requirements in Circular DEQ-12B, and the resulting load is more restrictive than the load that is currently included in their permit. They will need to develop an optimization/pollutant minimization program in their next permit.

Community C has not yet achieved the HAC treatment requirements in Circular DEQ-12B, and as a result will have their load limits in their permit decreased from 41 lb/day TN to 39 lb/day TN and 9.1 lb/day TP to 3.9 lb/day TP. They will be able to achieve the reduction in TN in two permit cycles which will then require them to develop an optimization/pollutant minimization program for TN, while they continue to work toward the HAC treatment requirements for TP.

Business D has an existing permit average monthly load limit, and will be capped at that level (7.5 lb/day TN) because it is lower (more restrictive) than the permit limit derived using the HAC treatment requirement in Circular DEQ-12B, which is 12.9 lb/day TN. Business D will also be required to develop an optimization/pollutant minimization program for TN. Business D's phosphorus concentrations are higher than (worse than) the HAC treatment requirements in Circular DEQ-12B, and so they will be required to improve their treatment levels from the current permit limits of 2.1 lb/day TP to 1.3 lb/day TP. See also response to COMMENT NO. 28.

COMMENT NO. 51: The nutrient standards and their implementation cannot result in a regulatory moratorium on new business in Montana.

RESPONSE: The numeric nutrient standards contained in Circular DEQ-12A are beyond the scope of this rulemaking. Pursuant to the authority granted by the Legislature at Section 75-5-313, MCA, the department is adopting amendments to ARM 17.30.660 and Circular DEQ-12B, pertaining to nutrient standards variances. The variance procedures contained in Circular DEQ-12B should allow time for nitrogen and phosphorus removal technologies to improve and become less costly.

COMMENT NO. 52: 40 CFR 131.14(a)(3) states that "A WQS variance, once adopted by the State and approved by EPA, shall be the applicable standard . . ." Because of this federal requirement, the department should reference in Circular DEQ-12B that water quality standards can be incorporated into a permit following EPA approval.

RESPONSE: The department recognizes that under the federal regulations, the variances described in Circular DEQ-12B are not effective for Federal Clean Water Act purposes until such time as EPA issues a water quality standards approval pursuant to 40 CFR 131.21. For federal law purposes, this provision is effective without a change in Circular DEQ-12B. No change was made to Circular DEQ-12B as a result of this comment.

COMMENT NO. 53: We are not aware of any effort by DEQ or EPA to complete an environmental assessment under MEPA of the impacts of the proposed rule revisions to the nutrient criteria.

RESPONSE: Modification of the variance rule is not a state action that triggers the requirement to prepare an environmental assessment. Modification of the circular does not authorize a permittee to discharge to state waters. That authorization is contained in a discharge permit. Issuance of a discharge permit does trigger the environmental assessment, and it is at the time of permitting that actual impacts can be determined and assessed.

COMMENT NO. 54: The department's proposed revisions to the variance rules and Circular DEQ-12B are not consistent with the intent of Senate Bill 367 and the adopted enabling statute (75-5-313(5)(b), MCA) which require the department to grant a general variance to any permittee that may apply for one.

RESPONSE: The department does not agree that the 75-5-313(5)(b), MCA, requires the department to grant the general variance to any permittee under all circumstances. The enabling statute does not state that any permittee, regardless of need, is entitled to the general nutrient standards variance. The underlying numeric nutrient criteria addressed by the variance have still been retained and must be achieved, if feasible. If certain permittees are already able to achieve the numeric nutrient criteria, they are not eligible to receive a variance.

COMMENT NO. 55: In Section 2.0 of Circular DEQ-12B, the department has struck the following: ". . . a permittee who meets the end-of-pipe treatment requirements provided below in Table 12B-1 may apply for and the department shall approve a general nutrient standards variance ("general variance") (§ 75-5 -313(5)(b), MCA)". We would like to see the following reinserted - "A permittee who meets the requirements provided below in Table 12B-1 may apply for and the department shall approve a general nutrient standards variance ("general variance") (§ 75-5 -313(5)(b), MCA)."

RESPONSE: The department agrees that 75-5-313(5)(b), MCA, provides that a variance shall be given if certain requirements are met. However, the previous language of Circular DEQ-12B has caused confusion. Because the underlying numeric nutrient criteria found at Circular DEQ-12A remain the underlying water quality standards, the department seeks to clarify that those permittees that can currently meet the requirements of Circular DEQ-12A are not eligible to receive the general variance. Furthermore, and to the extent eligible permittees are entitled to the variance under 75-5-313(5)(b), MCA, the statute speaks for itself and there is no need to unnecessarily repeat statutory language. See 2-4-305(2), MCA.

COMMENT NO. 56: The department's process to modify Circular DEQ-12B with highest attainable condition limits is inconsistent with statute at 75-5-313(7)(b), MCA which states that "If more cost effective and efficient treatment technologies are available, the concentration levels provided in subsection (5)(b) must be updated . . ."

RESPONSE: A water quality standards variance must include the requirements that apply throughout the term of the variance; such requirements must represent the highest attainable condition as a quantifiable expression. See 40 CFR 131.14(b). The department does not agree that a quantifiable expression of the highest attainable condition is inconsistent with 75-5-313(7)(b), MCA. The statute requires the approval of a general nutrient standards variance with concentration levels and periodic updates to those levels. Following consultation with the Nutrient Work Group and appropriate justification for updating the general variance concentration levels, the department proposed the necessary updates pursuant to 75-5-313(7), MCA.

COMMENT NO. 57: Section 2.2 and 2.3 of draft Circular DEQ-12B exceed the department's authority under state statute and should be modified to align with 75-5-313(9), MCA. The department's authority is limited to receiving the optimization plan.

RESPONSE: EPA's variance regulation, 40 CFR 131.14, requires that the permittee, upon achieving the highest achievable condition, prepare a pollution minimization program. This program is the equivalent of the optimization plan required 75-5-313(9), MCA. For this reason, the circular has been modified to replace the current optimization language with the pollution minimization requirement. Section 75-5-313(9), MCA, provides that the permittee evaluate operations to optimize nutrient reduction. The department has the duty to administer and enforce the water quality statutes. To perform these functions, the department needs to review the pollutant minimization program. Therefore, the department has retained the review and approval functions. Permitting requirements are governed by subchapter 13 of the water quality rules. Therefore, reference to subchapter 13 has been added for incorporation of the pollution minimization requirements into the permit.

COMMENT NO. 58: The language to minimize the reach of ARM 17.30.619(2) in the revised edition of Circular DEQ-12B must be stricken.

RESPONSE: If any portion of Table 12B-1 is not deemed invalid or disapproved, then such portion or portions would remain in effect and general variances would still be available. A partial invalidation or approval of Table 12B-1 would be partial, whether or not the sentence to which the commenter objects is adopted. The last sentence of Section 2.0 of Circular DEQ-12B has been removed.

Reviewed by: DEPARTMENT OF ENVIRONMENTAL

QUALITY

/s/ John F. North BY: /s/ Tom Livers

JOHN F. NORTH TOM LIVERS

Rule Reviewer Director

Certified to the Secretary of State, June 12, 2017.