(dissenting).
I respectfully dissent. Because I conclude that the Minnesota Pollution Control Agency (MPCA) has violated a federal Clean Water Act regulation, I would affirm the result reached by the Minnesota Court of Appeals and remand for further consideration by the MPCA.
*319Unlike the majority, I conclude that the provision of the Clean Water Act which requires the MPCA to “[ejstablish effluent limits using a calculated numeric water quality criterion for the pollutant which the permitting authority demonstrates will attain and maintain applicable narrative water quality criteria and will fully protect the designated use” is not ambiguous as applied in this case. 40 C.F.R. § 122.44(d)(l)(vi)(A) (2008). The MPCA is required to both attain and maintain water quality standards. See id. Increasing the in-lake phosphorus levels in Lake Winona does not meet that requirement. Therefore, I disagree with the majority’s conclusion that the requirement that the MPCA “attain and maintain” water quality standards is so ambiguous as to allow the MPCA to issue a permit that neither attains nor maintains the water quality of Lake Winona, but rather may well result in further degradation of the lake’s water quality.
As a prelude to my analysis, a brief review of the facts and procedural history of this case, especially the court of appeals decision, is in order. This matter arises out of a decision by the MPCA to reissue a National Pollutant Discharge Elimination System (NPDES) permit to the Alexandria Lake Area Sanitary District (ALASD) for an existing and expanding wastewater treatment facility. The existing facility discharges treated effluent into Lake Wi-nona. Lake Winona is in Douglas County and located on the west side of the City of Alexandria.
In 2004, the MPCA included Lake Wino-na in its list of “impaired waters” under the Clean Water Act due to excess phosphorus levels, which are also referred to as excess nutrient levels. The impaired listing indicates that Lake Winona is unsuitable for its designated uses of aquatic life and recreational activities. Lake Winona is part of a small watershed with only two main point sources of phosphorus, which are the ALASD facility and the City of Alexandria stormwater collection system. The effluent from the ALASD facility contributes 89 percent of the phosphorus load in Lake Winona. According to respondent Minnesota Center for Environmental Advocacy, the phosphorus concentration in Lake Winona is approximately four times what it should be to meet established water quality standards. More specifically, MPCA reports show that the 2005 in-lake phosphorus concentration in Lake Winona is 219 micrograms per liter. MPCA’s water quality standards indicate that the in-lake concentration will have to be reduced to 60 micrograms per liter in order to meet the established water quality standards.
Having identified Lake Winona as an impaired body of water, the MPCA must, under the Clean Water Act, establish a “total maximum daily load” for each pollutant that causes the lake to fail to meet water quality standards. See 33 U.S.C. § 1313(d) (2006); see also Minn.Stat. § 114D.20, subd. 2 (2008). After an extensive technical study, a total-maximum-daily-load results in a pollution reduction plan. See Minn.Stat. § 114D.20 (2008). In numerical form, a total-maximum-daily-load represents the sum of pollutants a body of water can absorb from all sources, plus a margin of safety, and still meet established water quality standards. See id. The total-maximum-daily-load process for Lake Winona began in 2006 and is expected to be completed in 2009.
In 2005, ALASD submitted an application to the MPCA for reissuance of an NPDES permit to continue operating its existing wastewater treatment facility that discharges phosphorus effluent into Lake Winona and to construct and operate an expanded facility that would also discharge phosphorus effluent into the lake. The *320expansion was requested to accommodate anticipated population growth in the Alexandria area, as well as to make wastewa-ter treatment improvements.1 In June 2006, the MPCA approved the reissuance of a five-year permit and approved the expansion of the facility. In approving the permit, the MPCA concluded that the phosphorus effluent limits in the permit complied with all applicable state and federal water quality standards.
The Minnesota Center for Environmental Advocacy challenged the approval of the reissued permit in the court of appeals. That court reversed, concluding that the reissued NPDES permit violated a federal Clean Water Act regulation by (1) setting phosphorus effluent limits for the ALASD facility that do not comply with and protect water quality standards; and (2) allowing the MPCA to delay development of more stringent effluent limitations until after the total-maximum-daily-load process is completed. The court of appeals remanded the case to the MPCA for further proceedings consistent with its opinion.
This case concerns what deference, if any, should be given to the MPCA’s interpretation of a Clean Water Act regulation enforced and administered by the MPCA. We recently addressed a similar issue in a 2007 case involving an NPDES permit for a new wastewater treatment facility under an analogous federal regulation that applies to new dischargers. In re Cities of Annandale and Maple Lake NPDES/SDS Permit Issuance for the Discharge of Treated Wastewater, 731 N.W.2d 502 (Minn.2007). Although ALASD’s case was decided after our decision in Annandale, MPCA and ALASD contend that the court of appeals’ decision is directly contrary to Annandale and will have a broader effect because the court of appeals decision will affect all existing and expanding wastewa-ter treatment facilities in Minnesota.
“The CWA is the cornerstone of surface water protection in the United States.” Id. at 509. This case concerns water quality standards. Water quality standards define the goals for a body of water by designating uses, setting criteria to protect those uses, and establishing provisions to protect water quality from pollutants. See 33 U.S.C. § 1313(c)(2)(A) (2006). There are two kinds of water quality standards— numeric and narrative. Am. Paper Inst., Inc. v. U.S. EPA, 996 F.2d 346, 349 (D.C.Cir.1993). This case concerns a narrative standard. A narrative standard is a statement of unacceptable conditions in or upon a body of water. See Minn. R. 7050.0150 subp. 1 (2005). The narrative standard for Lake Winona, a Class 2 body of water, indicates, in part, that there should be “no material increase in undesirable slime growths or aquatic plants, including algae.” Minn. R. 7050.0150, subp. 3 (2007).2
The Clean Water Act regulation at issue, 40 C.F.R. § 122.44(d) (2008), applies to NPDES permits for existing and ex*321panding wastewater treatment facilities. Citing our decision in Annandale, the court of appeals stated that it would defer to the MPCA’s interpretation of the Clean Water Act regulation if the regulation is ambiguous and the agency’s interpretation is reasonable. In re Alexandria Lake Area Sanitary District NPDES/SDS Permit No. MN0040738 (ALASD), No. A06-1371, 2007 WL 2421527, at *3 (MinnApp. Aug. 28, 2007) (citing Annandale, 731 N.W.2d at 516). The court concluded that the regulation here is complex, but not ambiguous. Id. at *8. The court also concluded that the MPCA’s interpretation of the regulation was not reasonable, and therefore, the court gave no deference to the MPCA’s interpretation. Id.
The Clean Water Act regulation at issue here requires NPDES permits to include conditions and establish effluent limitations that meet and protect water quality standards. 40 C.F.R. § 122.44(d)(1) (2008). The regulation provides:
Limitations must control all pollutants ... [that] are or may be discharged at a level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State water quality standard, including State narrative criteria for water quality.
40 C.F.R. § 122.44(d)(1)®. The MPCA acknowledges that the phosphorus discharge from the ALASD facility causes or contributes to the violation of MPCA’s narrative water quality standard for nutrient conditions in Lake Winona.
When a discharge causes or contributes to the violation of a narrative water quality standard and the state has not yet established a “water quality criterion” for the pollutant, the state has three options for establishing effluent limits. Id. § 122.44(d)(l)(vi). The MPCA chose the following option for Lake Winona:
Establish effluent limits using a calculated numeric water quality criterion for the pollutant which the permitting authority demonstrates will attain and maintain applicable narrative water quality criteria and will fully protect the designated use. Such a criterion may be derived using a proposed State criterion, or an explicit State policy or regulation interpreting its narrative water quality criterion, supplemented with other relevant information.... .
Id. § 122.44(d)(l)(vi)(A) (emphasis added). Additionally, the regulation provides the following guidance on establishing effluent limits:
When developing water quality-based effluent limits under this paragraph the permitting authority shall ensure that:
(A) The level of water quality to be achieved by limits on point sources established under this paragraph is derived from, and complies with all applicable water quality standards; and
(B) Effluent limits developed to protect a narrative water quality criterion, a numeric water quality criterion, or both, are consistent with the assumptions and requirements of any available wasteload allocation for the discharge prepared by the State and approved by EPA pursuant to 40 CFR 130.7.
Id. § 122.44(d)(l)(vii).
The following chart indicates the effluent limits imposed by the MPCA for the ALASD facility:
*322[[Image here]]
Acting under 40 C.F.R. § 122.44(d)(l)(vi)(A), the MPCA developed effluent limits for the ALASD facility based on Minnesota’s “phosphorus rule,” which is derived from an “explicit state policy”: an October 2005 fact sheet entitled MPCA Guidance for Issuing NPDES Permits for Discharge to Impaired Waters: Expanding Facilities (October 2005 Guidance). The phosphorus rule provides that when phosphorus discharge to a lake is actually or potentially detrimental to the designated water uses, dischargers must remove phosphorus to the “fullest practicable extent.” Minn. R. 7050.0211, subp. la (2007) (also specifying that phosphorus removal must be at least 1.0 mg/liter). The MPCA concluded that an average of 0.3 mg/liter was the optimum level of performance that could be achieved at the ALASD facility, taking into account the facility’s methods for removing phosphorus, as well as “the practicability of technologies to remove phosphorus from municipal waste-water.” Because operations during construction of the expansion could make it more difficult for the facility to achieve stringent performance levels, the MPCA imposed more flexible limits during an interim period.
In approving the permit, the MPCA determined that the effluent limits “are fully consistent and in compliance with applicable state and federal laws and rules, including 40 CFR 122.44(d)(1).” The MPCA evaluated five scenarios to assess the potential impact of the facility’s expansion. Although the models predicted that phosphorus levels within Lake Winona would increase during the time frame of the reissued permit, the MPCA found that any “additional phosphorus does not equate to dramatic increase in algal levels.” The MPCA asserts that its modeling showed that any additional phosphorus would not affect the nutrient conditions of the lake and there would be no change in levels of chlorophyll-a or water clarity.
The MPCA also indicated that the phosphorus limits were supported by the MPCA’s interim permitting policy, which applies to discharges to impaired waters with no total-maximum-daily-load. Although the MPCA, on appeal to our court, appears to be backing away from this policy, the policy provides that when waters are identified as impaired and there is no completed total-maximum-daily-load, there should be no further degradation of the waters pending issuance of the total-maximum-daily-load. In this case, the MPCA determined that the permit would have the effect of requiring ALASD to maintain or improve its current level of phosphorus removal.
The court of appeals reversed the MPCA’s decision to approve the permit, concluding that the MPCA’s approach *323“does not comply with 40 C.F.R. § 122.44(d)(1).” In re ALASD, 2007 WL 2421527, at *6. According to the court of appeals, the MPCA’s “reliance on its phosphorus rule and on its October 2005 Guidance and interim permitting policies is misplaced” because the phosphorus effluent limits in the permit will not “attain and maintain” the narrative water quality criteria and “fully protect” Lake Winona’s designated use. Id. at *8. The court stated:
• The reissued permit’s interim limits of 0.8 mg/liter phosphorus concentration and 11.3 kg/day mass load “would result in a more-than-doubling of the in-lake phosphorus concentration of Lake Winona”; and
• The final limits of 0.3 mg/liter phosphorus concentration are “based on what the proposed facility is designed to achieve, rather than what is required for the lakes to attain and maintain water quality,” and the modeling results show that the in-lake phosphorus concentration within Lake Winona would increase slightly.
Id. at *6, 7.
Based on the projected increase in the concentration of phosphorus, the court of appeals determined that the limits in the permit are not “water quality-based” effluent limits within the meaning of 40 C.F.R. § 122.44(d)(1). Id. at *7, 8. The court stated that “[t]he excess phosphorus concentration, whether it is more than the algae can absorb, will serve to keep the in-lake concentration further removed from attaining the required water-quality goal.” Id. at *6. Based upon the foregoing analysis, the court concluded that “the interim and final effluent limits in the reissued permit for the ALASD facility are not conditions that will ensure compliance with water-quality standards, as required' by federal law.” Id.
The court of appeals also concluded that the MPCA incorrectly interpreted 40 C.F.R. § 122.44(d)(1) as allowing the MPCA to defer development of more stringent effluent limitations until after the total-maximum-daily-load process is completed. Id. at *7. Although the MPCA argued that the regulation has the primary purpose of ensuring that impaired waters are not further degraded before a total-maximum-daily-load is completed, the court stated that “[t]he regulation requires effluent limits that are ‘developed to protect a narrative water quality criterion’ and ‘will fully protect the designated use’ of the body of water”; “[njowhere in the [Clean Water Act] or the regulation itself is it stated or suggested that the goal should be to avoid further degradation of impaired waters.” Id. The court stated, “merely holding the line on existing pollution levels is not enough.” Id.
On appeal, MPCA and ALASD assert that the court of appeals decision is directly contrary to our decision in Annandale and will have adverse statewide consequences. The MPCA argues that the court of appeals decision strips MPCA of any deference in exercising its scientific policy judgment in implementing an extremely important water quality regulation with far-reaching implications. The MPCA contends that here the case for deference is more compelling than in An-nandale, because (1) the derivation of numeric effluent limits requires the MPCA to use its expert scientific judgment; (2) the need for administrative interpretation is supported by the language of the regulation, the Environmental Protection Agency’s (EPA) regulatory history, and federal case law; and (3) the EPA expressly approved the MPCA’s administrative interpretation. The MPCA also contends that the court of appeals incorrectly concluded that any amount of additional phosphorus *324in an impaired water will worsen the impairment. MPCA and ALASD also contend that the court’s decision will upset the entire MPCA framework for the development of standards under the state’s impaired waters program. They assert that the practical impact of the court’s decision will be that the MPCA will not be able to reissue an NPDES permit to any existing discharger to an impaired body of water, whether expanding or not, unless the MPCA demonstrates the permit will ensure attainment of water quality standards — even when those standards are yet to be developed.
The Minnesota Center for Environmental Advocacy, on the other hand, asserts that the court of appeals decision was well reasoned and fully consistent with the analysis in Amándole. The Center contends that MPCA and ALASD are asking our court to essentially ignore the plain meaning of unambiguous Clean Water Act regulations that the MPCA is charged with implementing. According to the Center, federal regulations require NPDES permits to attain and maintain water quality standards, not to maintain violations of water quality standards. The Center claims that if the NPDES permit is reissued in its present form, Lake Winona will remain impaired or become slightly worse. To illustrate this point, the Center provided the following graphic illustration:
Phosphorus Concentration in Lake Winona
[[Image here]]
To some extent, I agree with MPCA’s assertion that the court of appeals may not have fully appreciated all the complexities involved in addressing phosphorus limits in NPDES permitting when a total-maximum-daily-load is underway. Although the court was “mindful that the regulation allows MPCA some latitude to determine *325the appropriate procedures for developing water quality-based effluent limits,” in rejecting the interim and final effluent limits, the court may not have given sufficient consideration to the following factors:
• Because of the uncertainties of construction, a flexible approach may have been necessary during the interim period while the facility was undergoing improvements that would enhance phosphorus removal;
• The MPCA did consider both the facility’s methods for removing phosphorus as well as “the practicability of technologies to remove phosphorus from municipal wastewater” in concluding that the 0.3 mgditer was “the fullest practicable extent of phosphorus removal”; and
• The 0.3 mg/liter concentration limit appears to be equivalent to the most restrictive phosphorus limit ever established by the MPCA.
I also acknowledge that there are numerous practical difficulties associated with restoring an impaired lake such as Lake Winona to its designated use. The MPCA notes that the effluent limits in the permit would not be sufficient to restore Lake Winona, but argued that the 0.3 mg/liter interim phosphorus limit was a reasonable interim step in moving toward attainment of the narrative water quality standard. MPCA asserts that, taken together with the total-maximum-daily-load-based effluent limit in the schedule of compliance, a 0.3 mg/liter limit would assure that the water quality standard would be attained. The MPCA asserted in its brief to the court of appeals that “restoration will likely require many years of effort, including measures other than point source effluent limits.” Nevertheless, and in the context of the aforementioned reservations, I agree with the result reached by the court of appeals. I conclude that by granting the ALASD the new five-year permit at issue here, the MPCA has failed to comply with the requirements of federal regulation 40 C.F.R. § 122.44(d)(1).
The Clean Water Act requires states to establish water quality standards to “protect the public health or welfare, enhance the quality of water and serve the purposes of [water pollution, prevention, and control.]” 33 U.S.C. § 1313(c)(2)(A). A state’s ■ water quality standards must be established “taking into consideration [each body of water’s] use and value for public water supplies, propagation of fish and wildlife, recreational purposes, and agricultural, industrial, and other purposes, and also taking into consideration their use and value for navigation.” Id. Each state must identify those waters within its boundaries that are impaired under the Clean Water Act. Id. § 1313(d)(1)(A). Lake Winona, as previously noted, has been identified as an impaired body of water, i.e., a Class 2 body of water impaired due to excessive phosphorus. See Minn. R. 7050.0200, subp. 3 (2007) (defining “Class-2 water” as those capable of supporting “aquatic life” and “recreation”).
Based upon Lake Winona’s identification as an impaired body of water the majority correctly concludes, and the MPCA acknowledges, that the ALASD facility will “cause or contribute” to the violation of applicable water quality standards. Accordingly, in order to achieve established water quality standards the MPCA must establish effluent limits in any NPDES permit for ALASD that are more stringent than ordinarily required under the Clean Water Act.
As previously noted, the MPCA has chosen a water quality standard for Lake Winona that is based on a narrative criterion. The critical part of the dispute before us is whether the narrative criteria chosen by the MPCA is ambiguous. Un*326like the majority, I conclude the MPCA’s narrative criteria is unambiguous as applied here. I find no ambiguity in the words “will attain and maintain applicable narrative water criteria and will fully protect the designated use” as these words are applied to ALASD’s permit. 40 C.F.R. § 122.44(d)(1)(vi)(A). Quite simply, as applied in this case, the requirement to “attain and maintain” the water quality criteria and “fully protect the designated use” unambiguously precludes the MPCA from issuing a permit that, for the foreseeable future, allows a net increase in the concentration of phosphorus in Lake Winona. Given this lack of ambiguity, I conclude that the ALASD permit as granted does not comply with the law.3
The majority’s assertion that my analysis fails to set forth a standard for “how quickly water quality standards for an impaired lake such as Lake Winona must be attained” misses the point. The issue here is not how quickly progress will be made, but whether progress will be made at all. As an impaired waterbody, Lake Winona must attain water quality standards and be returned to its designated use within a reasonable period of time. Under the reissued permit, in-lake phosphorus concentration in Lake Winona will not decrease and may well increase. MPCA modeling shows that with a fluid permit effluent limit of 0.3 mgditer phosphorus concentration, the in-lake concentration will increase slightly even with the 5.4 kg/day mass load limits for phosphorus allowed by the permit. The in-lake concentration will be even worse under the 0.8 mg/liter and 11.3 kg/day interim limits.
I take little solace from MCPA’s assertion that because the phosphorus level in Lake Winona is very high, additional phosphorus will not equate to any dramatic increase in algae levels. It is hard to avoid the fact that excess phosphorus concentration, even if it is more than the algae can absorb, will keep in-lake phosphorus concentration levels further away from the target water quality of 60 micrograms per liter. The MCPA’s own calculations suggest that after five years the net impact of ALASD’s permit would be an increase in the phosphorus concentration of Lake Wi-nona. The notion that one attains and maintains water quality through further degradation of Lake Winona defies common sense.
I also conclude that the MPCA cannot interpret the Clean Water Act regulations as allowing it to defer development of more stringent effluent limitations that will meet water quality standards until after it completes the total-maximum-daily-load process. 40 C.F.R § 122.44(d)(l)(vii)(B) (“Effluent limits developed to protect a narrative water quality criterion ... [must be] consistent with the assumptions and requirements of any available wasteload allocation ....”) (emphasis added). Because MPCA has not yet completed the total-maximum-daily-load process with its individual waste load-allocation components, MPCA asserts that it is not required to set more stringent effluent limits until that process has been completed. But, the EPA, in its preamble *327to the rule changes to 40 CFR § 122.44(d)(1), made it clear that MPCA may not wait to set more stringent effluent limits, but that it must do so at the time the permit is issued:
[A]ny effluent limit derived under paragraph (vi) must satisfy the requirements of paragraph (vii). Paragraph (vii) requires that all water quality-based effluent limitations comply with “appropriate water quality standards,” and be consistent with “available” waste load allocations. Thus for the purposes of complying with paragraph (vii), where a wasteload allocation is unavailable, effluent limits derived under paragraph (vi) must comply with narrative water quality criteria and other applicable water quality standards.
National Pollutant Discharge Elimination System; Surface Water Toxics Control Program, 54 Fed.Reg. 23868, 23878 (June 2,1989) (emphasis added).
Finally, MPCA may not justify waiting until total-maximum-daily-load completion to establish more stringent effluent limits on the ground that it has incorporated a “schedule of compliance” as a condition in the reissued permit by requiring the ALASD facility to “comply with permit conditions which are determined by the MPCA to be consistent with the [facility’s] waste load allocation for phosphorus.” See Minn. R. 7001.0140 subp. 1 (2007) (requiring MPCA to reissue a permit if it determines that the facility “comply or will undertake a schedule of compliance to achieve compliance with all applicable state and federal pollution control statutes and rules”); 40 C.F.R. § 122.47(a) (2008) (“per-mitís] may, when appropriate, specify a schedule of compliance leading to compliance with CWA and regulations”). There is no enforceable sequence of actions in the reissued permit leading to compliance with water quality-based effluent limits. There are no mandated dates by which MPCA must complete the total-maximum-daily-load process or develop effluent limits based on the total maximum daily load it develops. Simply providing that once Lake Winona’s total maximum daily load is approved, the facility shall comply with permit conditions determined by MPCA to be consistent with the facility’s waste load allocation for phosphorus does not constitute a schedule of compliance.
Even if MPCA were allowed to wait until completion of the total-maximum-daily-load process before establishing effluent limits that are water quality-based effluent limits within the meaning of the Clean Water Act and 40 C.F.R. § 122.44(d)(1), the reissued permit has no date by which the facility would be required to be in compliance with those limits. Finally, by deferring to the establishment of more stringent effluent limitations, MPCA has risked that the facility will not be able to comply with effluent limits that are developed after total-maximum-daily-load completion.
In conclusion, the MPCA has simply not done enough to protect Lake Winona from further degradation while the total-maximum-daily-load process is being completed. Water quality standards are important in Minnesota. Minnesota has more surface waters than any of the 48 contiguous states — and a large number of our state’s waters are impaired. Our court’s decision today will likely affect NPDES permits for existing and expanding waste-water treatment facilities that discharge to or upstream from a body of water listed as impaired due to excess phosphorus levels when a total-maximum-daily-load has not yet been completed.4 The MPCA notes *328that of the approximately 1,400 permitted wastewater treatment facilities in the state, approximately 550 either discharge to an impaired water or discharge within the watershed of an impaired water.5 Because of the broad potential impact of our court’s decision, we must make sure we get it right. I conclude that merely holding the line or permitting some increase, even if the MPCA characterizes the increase as being slight, does not comply with MPCA’s narrative standard.
We must not lose sight of what this case is about. The Clean Water Act requires the MPCA to focus on attaining and maintaining a water quality for Lake Winona that will fully protect the lake’s designated use. Thus, notwithstanding some of the scientific and technical distractions in this case, the bottom line is whether the new permit attains and maintains the water quality in Lake Winona. The bottom line is that it does not.
I conclude that compliance with the Clean Water Act means that the MPCA must start now to “attain and maintain” established water quality standards for Lake Winona if the lake is to be restored to its designated use within a reasonable period of time. I have no delusions as to the enormity of the task and agree with the MPCA that restoration of Lake Wino-na is going to be a long and difficult task. Nor do I question the intent, purpose, and motives of the MPCA in seeking to deal with the question of reissuing a permit for ALASD’s facility. But Lake Winona’s water quality standard issue is squarely before our court. We are beyond the stage when merely shifting the deck chairs on a sinking ship will suffice. The law requires that the MPCA attain and maintain established water quality standards for Lake Winona; therefore, I would remand this case to the MPCA to do just that.
. ALASD is currently permitted to discharge 3.75 million gallons per day (average wet weather flow) into Lake Winona. In the current five-year permit it seeks permission to discharge up to 4.7 million gallons per day. By 2025, it proposes to discharge 6.7 million gallons per day.
. The court of appeals noted that the state water quality standard for Lake Winona is based on a narrative criterion. In re Alexandria Lake Area Sanitary District NPDES/SDS Permit No. MN0040738, No. A06-1371, 2007 WL 2421527, at *2 (Minn.App. Aug.28, 2007). The MPCA proposed a change to provide for a numeric criterion, and the rule was changed in December 2007, but the new rule is not applicable to the facts of this case. See Minn. R. 7050.0222, subp. 3 (2007).
. The majority’s claim that by dissenting, I attempt to substitute my judgment for the agency's technical expertise is misplaced. Anyone who has knowledge of our court's decision in Annandale, 731 N.W.2d at 502, must be cognizant of my awareness of our court’s obligation to grant the appropriate degree of deference to an agency's technical expertise. Because application of the statute here is unambiguous, see Annandale, 731 N.W.2d at 516, I conclude deference to the MPCA’s expertise in interpreting the statute is neither necessary nor justified and when this deference is neither necessary nor justified, our court has the obligation to say so.
. The 2008 Impaired Waters List announced by the MPCA shows 1,475 impairments on *328336 different rivers and 510 different lakes, with only a small percentage of rivers and lakes having been assessed. Minnesota Pollution Control Agency, Impaired Waters, http:// www.pca.state.mn.us/water/tmdl/tmdl-303 dlist.html# finallist (last visited March 6, 2009). Twenty-three percent of these impairments involve excess phosphorus levels. See id. The MPCA has observed that "[njutrient-impaired waters exist in every corner of the state.” Minnesota Pollution Control Agency, Pre-TMDL Phosphorus Trading Permitting Strategy, http://www.pca.state.mn.us/water/ tmdl/ptpt.html (last visited March 6, 2009). Phosphorus levels are relevant to the permitting of wastewater treatment facilities, because virtually all wastewater treatment facilities discharge phosphorus. See id.
. Minnesota Pollution Control Agency, Why impaired waters are a priority for Minnesota, February 6, 2004, http://www.pca.state.mn.us/ publications/leg-04sy2-02 .pdf.