TODD, Justice.
Plaintiffs, Citizens Against Power Plant Pollution, Inc. (CAPPP), a Minnesota nonprofit corporation composed of farmers and other residents of Sherburne County, and its president, Malcolm Olson, brought this action against the Minnesota Environmental Quality Board (MEQB), seeking declaratory and equitable relief under the Minnesota Environmental Rights Act (MERA), Minn.Stat. §§ 116B.01-.13 (1978). Plaintiffs challenged the MEQB’s November 1975 grant to defendant-intervenor Northern States Power Company (NSP) of a Certificate of Site Compatibility, pursuant to the Power Plant Siting Act (PPSA), Minn. Stat. §§ 116C.51-.69 (1978) (amended 1980), for two proposed large electric power generating plants of 800 megawatts each (Sherco 3 and Sherco 4) at a site in Sher-burne County where two other large electric power generating plants (Sherco 1 and Sherco 2) were already in operation.
Plaintiffs alleged, as their first cause of action, that the Certificate of Site Compatibility was invalid because it was issued before NSP had received a Certificate of Need (CON) for Sherco 3 and Sherco 4 from the Minnesota Energy Agency (MEA) pursuant to the Minnesota Energy Agency Act, Minn.Stat. § 116H.13 (1978 & Supp.1979) (amended 1980), or, alternatively, that the Certificate of Site Compatibility became invalid when, in March 1978, the MEA voided the CON as to Sherco 4 and as to the timing of Sherco 3.
As to their second cause of action, plaintiffs alleged that the Certificate of Site Compatibility was invalid because the MEQB had failed to consider the environmental and health effects of siting four power plants at the Sherco site, particularly in light of the threat of an accident at the nuclear power plant operating nearby.
Third, plaintiffs alleged that the Certificate of Site Compatibility was invalid because the MEQB had failed to seek and evaluate feasible and prudent alternatives to the Sherco site. Additionally, plaintiffs [578]*578urged before the district court that the MEQB was without jurisdiction to grant NSP the Certificate of Site Compatibility for the Sherco site because the Minnesota Legislature had designated a site at Henderson, in Sibley County, for NSP’s new generating facilities.
In a comprehensive order and memorandum, the Ramsey County District Court granted summary judgment in favor of defendants on plaintiffs’ first cause of action and on the challenge to the MEQB’s jurisdiction, dismissed the allegations regarding the nuclear hazard as outside the scope of MERA but otherwise remitted the second cause of action to the MEQB for further consideration of the environmental and health effects of Sherco 3, and, finally, dismissed plaintiffs’ third cause of action on the basis of laches. Plaintiffs appeal from all of the district court’s rulings except that remitting the second cause of action. We affirm.
The appeal raises the following issues for our consideration: (1) whether the MEQB was without jurisdiction to grant NSP a Certificate of Site Compatibility for the Sherco site because the legislature exclusively designated a site at Henderson, Minnesota, for this particular electric generating facility; (2) whether plaintiffs’ allegation that the siting of a coal-fired power plant near a nuclear generating facility could have an adverse environmental and reliability impact states a claim under MERA; (3) whether the MEQB erred in refusing to reconsider the Certificate of Site Compatibility for Sherco 3; and (4) whether plaintiffs’ claim that the MEQB failed to consider alternatives to the Sherco site is barred by laches.
These issues are difficult and complex. We recognize, as the trial court did, the hard task of the MEA and the MEQB in balancing, on the one hand, the public need for electric power and, on the other hand, the risks to human life, health, and environment generally from power plants and power lines. To understand the issues and to decide them as best we can, it is necessary to see the case in its factual, chronological setting extending over eight years.
Facts and Procedural History
On April 5, 1972, Governor Wendell Anderson, by executive order, created the Governor’s Environmental Quality Council (GEQC), composed of the Governor, the Directors of the Minnesota Pollution Control Agency (MPCA) and the State Planning Agency, and the Commissioners of Natural Resources and Highways. Eight days later, NSP sought the GEQC’s recommendation regarding the site for a 1,600-megawatt coal-fired electric generating facility to be operating by 1979-80. In May of 1972, the GEQC created a 23-member power plant siting task force and directed it to examine the need for the plant and to make a recommendation regarding siting.
The task force considered 15 potential sites, seven of which were identified in a study prepared by NSP for a private consulting firm and provided by the task force. After public meetings in the site areas and site tours by task force members, the task force issued its report in December 1972, recommending as its first choice a site in Sherburne County, Minnesota, where a 1,360-megawatt NSP facility in two plants, Sherco 1 and 2, was being constructed. The task force recommended that its second choice, a site at Henderson in Sibley County, Minnesota, be utilized if the GEQC established that the Sherburne County site would have substantially greater air quality impact, and recommended as its third choice a site at Jordan in Carver County, Minnesota.
In January 1973, the GEQC met and considered the task force report, a Minnesota State Planning Agency report indicating that the Sherburne County site would have greater air quality impact than the Henderson site, and a letter from the MPCA, also expressing concern about the effect that two additional plants at the Sherco site might have on ambient air quality standards. The GEQC voted four-to-one to recommend the Henderson site for construction of NSP’s next electric generating plant, with the Jordan site as a second [579]*579choice. The GEQC sent its recommendations to NSP by letter of February 1, 1973. On February 6, 1973, NSP indicated that it would begin preparing design and engineering studies to construct its facility at the Henderson site.
On May 23, 1973, the legislature enacted the PPSA, which gave the newly created Minnesota Environmental Quality Council1 authority to “provide for power plant site * * * selection.” Act of May 23, 1973, ch. 591, § 3, 1973 Minn.Laws, 1343, 1344 (current version at Minn.Stat. § 116C.53, subd. 2 (1978)). The PPSA provides that any new electric generating facility may be constructed only on a site designated by the MEQB in accordance with criteria2 which the act required the MEQB to develop with public participation. Minn.Stat. §§ 116-C.53, .55, .57 (1978). No later than one year after a utility requests designation of a site, the MEQB must designate such a site and issue a “Certificate of Site Compatibility,” which constitutes the sole site approval a utility must obtain. Id. §§ 116C.57, ‘ .61. The time for designation “may be extended for six months” by the MEQB “for just cause.” Id. § 116C.57, sub. 1. The legislature adopted the following “savings clause” as part of the PPSA:
The provisions of this act shall not apply to the site for the large electric power generating plant evaluated and recommended by the governor’s environmental quality council prior to the date of enactment, and also to high voltage transmission lines, the construction of which will commence prior to July 1,1974; provided, however, that within 90 days following the date of enactment, the affected utility shall file with the council a written statement identifying such transmission lines, their planned location, and the estimated date for commencement of construction.
Act of May 23, 1973, ch. 591, § 17, 1973 Minn.Laws 1343, 1351 (current version at Minn.Stat. § 116C.67 (1978)). The PPSA was adopted, as noted, in May 1973; regulations establishing procedures for siting of new plants were adopted August 2, 1974.
On March 28, 1974, the legislature enacted the Minnesota Energy Agency Act, which created the MEA and gave that body authority to make decisions regarding the need for new power plants in the state pursuant to criteria which the MEA was required to adopt by July 1, 1976. See Act of Mar. 28, 1974, ch. 307, 1974 Minn.Laws 494 (codified at Minn.Stat. §§ 116H.001-.15 (1978) (amended 1979, 1980). Later that year, on November 1, 1974, NSP, having determined that the Henderson site was less desirable than the Sherburne County [580]*580site, applied to the MEQB for a Certificate of Site Compatibility for two 800-megawatt units at the Sherco site pursuant to the PPSA. By letter of November 11, 1974, NSP “indicated that it would waive the exempt status of the Henderson site if the Sherburne County site were ultimately certified by the MEQB for an additional 1,600 megawatts of generating capacity.” At its next session, the legislature amended the Minnesota Energy Agency Act to require the MEA to promulgate criteria for determination of need for new power plants by September 15, 1975, and provided:
On and after the effective date of the assessment of need criteria adopted pursuant to subdivision 1, no large energy facility shall be sited or constructed in Minnesota without the issuance of a certificate of need by the director pursuant to sections 116H.01 to 116H.15 and consistent with the criteria for assessment of need.
Act of May 17, 1975, ch. 170, § 4, 1975 Minn.Laws 498, 499 (codified at Minn.Stat. § 116H.13, subd. 2 (1978)). The MEA adopted CON regulations on September 30, 1975.3
Meanwhile, the MEQB’s consideration of NSP’s application for a Certificate of Site Compatibility proceeded. The Minnesota Pollution Control Agency took exception to the MEQB’s willingness to grant site certification to NSP before a determination of need for the proposed plant had been made. In May 1975, the MPCA made the following statement concerning this process:
The Agency believes very strongly that (1) the need for the plant had not been justified, and (2) its construction will cause an unwarranted further deterioration of air quality and degradation of water quality as the result of the discharge of gaseous and liquid wastes from the operation of the plant.
* * * * * *
The Agency wishes to express its deep concern and disagreement with the proposed process of siting the plant first and justifying the need for it at some later date. We believe it is entirely proper and in fact the responsibility of the Council, in the absence of authority for formal action by the Energy Agency, to require the company to justify the need for this plant in advance of any decision with regard to the siting aspect.
Despite this protest, the MEQB conducted hearings on NSP’s application for a Certificate of Site Compatibility through the summer of 1975. The MEQB staff prepared an environmental report, dated August 1975, which indicates that the MEQB had not designated additional alternative sites but had considered only the Henderson and Sherco sites submitted by NSP because alternative sites had been eliminated by the work of the GEQC in 1972.4 A citizens committee appointed by the MEQB recommended the Sherco site by a 14-to-5 vote in its report submitted August 29, 1975.
On November 10, 1975, the MEQB issued a single Certificate of Site Compatibility for the Sherco site to NSP for Sherco 3 and [581]*581Sherco 4 and appointed the MPCA to prepare an Environmental Impact Statement (EIS) for those facilities. In its findings, the MEQB recognized the “pending requirement” that NSP obtain a Certificate of Need for the new generating units, but stated erroneously that the MEA had not yet implemented criteria and procedures for making CON determinations. The MEA’s regulations, as noted above, were in fact effective September 30, 1975, and on October 14, 1975, NSP had applied for a CON pursuant to those regulations for Sherco 3 and Sherco 4. Hearings on this application were conducted by the MEA in January 1976. On April 12, 1976, the MEA issued a single CON for Sherco 3 and Sherco 4 with in-service dates of May 1, 1981, and May 1, 1983, respectively.
It was during 1976 that Sherco 1, the first electric generating facility constructed by NSP at the Sherburne County site, became operational, and plaintiffs became aware of the effects on their land of coal-fired electricity generation. In December 1976, NSP requested MEQB’s authorization to begin preliminary construction work on Sherco 3 before the EIS was completed. While MEQB’s decision on NSP’s request was pending, farmers and other residents of Sherburne County incorporated plaintiff CAPPP, Inc., and retained counsel “to represent it at all levels of the Sherco 3 and 4 proceedings.” The MEQB granted authorization for NSP to begin limited preliminary work at the Sherco site on February 8, 1977, and July 13, 1977. The limited work authorization provided as follows:
THAT if NSP proceeds with the work described in this resolution, it does so entirely at its own risk recognizing the allowance of no vested property rights and recognizing that any work described in this resolution will not be relevant to nor be allowed as an argument or defense against any consideration of alternatives in the EIS process or against any permit conditions proposed by any person or agency in the permitting process on this matter * * *.
In June 1977, CAPPP, Inc., brought suit against NSP and the MEQB to challenge the issuance of the authorizations. On August 23, 1977, after hearing arguments from NSP, the AFL-CIO, and various state agencies that construction of Sherco 3 and 4 must begin in order to prevent future energy shortages, the MPCA granted an interim emission permit. CAPPP, Inc., expanded its lawsuit to challenge that permit.
On the morning of October 27, 1977, oral arguments were heard in the CAPPP, Inc., lawsuit. That afternoon, NSP announced it had new data that would revise downward its energy demand forecast. On November 1,1977, the MEQB revoked its limited work authorizations and instructed NSP to halt construction. The CAPPP lawsuit was dismissed without prejudice on November 22, 1977.
The MPCA conducted public hearings during November 1977 on the draft EIS in order to evaluate further the impact of Sherco 3 and Sherco 4 on human health. The final EIS indicates that operation of Sherco units 1 to 4 is likely to contribute substantially to high, short-term ambient SO2 (sodium dioxide) concentration, a significant health risk.
Following NSP’s downward revision of it- demand forecast, on March 23, 1978, the MEA issued its findings, conclusion, and order severing and voiding the Certificate of Need for Sherco 4. Regarding that facility, for which NSP now sought an in-service date of 1987, the MEA director found that this requested time delay “increases the possibility that changes in technology, economic factors, load characteristics, fuel options and political and social considerations” are likely to result in a change in the optimal size and type of the facility necessary. As to Sherco 3, however, the director indicated that, even if its in-service date were extended to 1984, changes in technology and alternatives available by that time are not likely to result in a change in the choice of size or type of facility needed. To secure valid need certification, however, MEA required NSP to initiate a rehearing on the timing of Sherco 3.
[582]*582In May and July 1978, CAPPP, Inc., requested that the MEQB declare the single Certificate of Site Compatibility voided by operation of the MEA’s March 23, 1978, order. The MEQB made no response to these requests. On August 21, 1978, NSP submitted an application to MEA seeking a 1984 in-service date for Sherco 3. On December 13, 1978, CAPPP, Inc., brought this lawsuit and served a second amended complaint on August 27, 1979. Plaintiffs challenged the issuance of the Certificate of Site Compatibility to NSP on November 19, 1975, for two 800-megawatt electric generating plants in Sherburne County, Sherco 3 and Sherco 4, alleging the claims set out above.
On October 29, 1979, the MEA director issued his findings, conclusions, and decision granting NSP an amended CON for Sherco 3 with an in-service date of May 1, 1985. On December 21, 1979, the Ramsey County District Court entered the order in this lawsuit from which CAPPP appeals.
Waiver of the Henderson Exemption
We consider first plaintiffs’ argument that the MEQB was without jurisdiction to grant NSP a Certificate of Site Compatibility for the Sherco site because the legislature exclusively designated a site at Henderson, Minnesota, for this particular electric generating facility. When the legislature enacted the PPSA, it adopted a section stating that its provisions “shall not apply to the site for the large electric generating plant evaluated and recommended by [the GEQC] prior to the date of enactment, and also to high voltage transmission lines, the construction of which will commence prior to July 1,1974,” provided that utilities seeking the power line exemption file a statement to that effect with the MEQB. Act of May 23, 1973, ch. 591, § 17, 1973 Minn. Laws 1343, 1351 (current version of Minn. Stat. § 116C.67 (1978)).5
In No Power Line, Inc. v. Minnesota Environmental Quality Council, 262 N.W.2d 312 (Minn.1977), this court considered the question of whether a utility which had filed a statement seeking the exemption provided by the second half of that “savings clause” could subsequently waive the exemption and submit to PPSA siting of its proposed line. We noted, first, that it is unusual for a party benefited by a “grandfather clause” exemption to affirmatively seek regulation. We concluded, however, that to allow an exempt utility voluntarily to seek the jurisdiction of the MEQB furthered the legislature’s purpose, which we characterized as follows:
By enacting the PPSA, the legislature sought to ensure that the future siting of power plants and transmission lines would be carried out in an orderly fashion according to a rational design, rather than haphazardly, and possibly unnecessarily, at the whim of individual public utilities whose decisions might fail to consider or comport with the public interest. Minn.St.1976, §§ 116C.55 to 116C.60. The two crucial concepts that permeate the entire act are that the process should be orderly and that there should be public participation in all stages of agency decision-making.
$ * * * ⅜ #
After long and serious deliberation, we have decided that the legislature would have intended MEQC to have jurisdiction based on our residual conviction that the legislature would have preferred the PPSA to apply to the fullest extent reasonably possible. Therefore, the legislature must have intended to permit the utilities to waive the exception it had carved out in their favor, even though exemption had previously been claimed and granted.
Id. at 321-22 (emphasis in original).
Plaintiffs seek to distinguish the power line exemption construed in No Power Line from the power plant exemption at issue here, noting that the power line exemption required an affirmative act on the part of any utility seeking to claim it. [583]*583A utility so exempt was required to seek permits from each county through which its power line ran, a fragmented, disorderly process. The power plant site exemption granted to NSP, on the other hand, demonstrated the legislature’s recognition of the orderly, public decision-making process which had resulted in selection of the Henderson sites, thus meeting the goals of the PPSA as identified in No Power Line. Plaintiffs argue further that to permit NSP to waive its exemption unilaterally, rather than to construe it as a legislative designation of the Henderson site, would grant NSP a “special or exclusive privilege” prohibited by Minn.Const. Art. 12, § 1.
Our decisions regarding “special legislation” establish that a law which applies to members of one class, even if it is a class of just one member, is not impermissible so long as the distinguishing characteristics of the class reasonably justify singular treatment. Visina v. Freeman, 252 Minn. 177, 195-99, 89 N.W.2d 635, 650-52 (1958); State v. Cloudy & Traverse, 159 Minn. 200, 198 N.W. 457 (1924). Granting an exemption for the Henderson site, not permitting its waiver, was the act by which the legislature conferred a special privilege on NSP. Like other “grandfather clauses”, the one at issue here was based upon differences reasonably justifying the legislature’s determination to exempt the Henderson site from the PPSA procedures and did not constitute impermissible special legislation. Nevertheless, we can see no objection to the desire of NSP to subject itself to the procedures of the PPSA. The district court correctly concluded that No Power Line stands for the proposition that the exemption provided by section 116C.67 may be waived by the beneficiary of that exemption. We affirm the determination that the MEQB properly exercised its jurisdiction to consider NSP’s application for certification of the Sherco site.
Nuclear Accident Threat
Plaintiffs, in their second cause of action, questioned the reliability of the electrical system in the event of a nuclear accident and alleged that siting Sherco 3 and 4 in proximity to the Monticello nuclear power facility could have adverse impact on human and environmental resources. The district court concluded that these allegations raised the issue of a possible atomic accident at the nuclear facility and that possible resulting evacuation or long-term shutdown of the Sherco facility threatens the loss of reliability of the electric supply, not damage to the environment. The court dismissed this claim as outside the scope of MERA, which provides a remedy “to protect air, water, land and other natural resources located within the state from pollution, impairment, or destruction.” Minn. Stat. § 116B.01 (1978).
We concur with the district court’s determination that the reliability of the Sherco facility to produce energy in the event of a nuclear accident at Monticello is, at bottom, a question of energy supply. A lawsuit brought to prevent a reduction in or loss of the supply of energy produced at Sherco is not brought “to preserve the environment in its natural state from pollution, impairment, or destruction.” See State ex rel Skeie v. Minnkota Power Cooperative, Inc., 281 N.W.2d 372, 373 (Minn.1979). These allegations were properly dismissed.
Continuing Validity of Certificate of Site Compatibility for Sherco 3
Plaintiffs argue, first, that the Certificate is void by operation of law because it was issued prior to issuance by the MEA of a CON, in violation of section 116H.13, subd. 2, which provides that “[o]n and after the effective date of the assessment of need criteria * * * no large energy facility shall be sited * * * without the issuance of a certificate of need * * The CON criteria became effective September 30, 1975. NSP was issued its Certificate of Site Compatibility on November 10,1975. The CON was not granted until April 12, 1976.
That the grant of a Certificate of Site Compatibility was outside of strict compliance with the law is clear from Minn.Stat. § 116H.13, subd. 2 (1978). Defendants point [584]*584out, however, that NSP applied for its Certificate of Site Compatibility on November 1,1974, and that the PPSA gives the MEQB only one year to designate a site and grant a Certificate. They argue that there was not enough time after September for NSP to procure a CON before the MEQB was required to grant the Certificate of Site Compatibility. In No Power Line, Inc. v. Minnesota Environmental Quality Council, 262 N.W.2d 312 (Minn.1977), this court approved the MEQB’s grant of a Certificate of Corridor Compatibility for a high voltage power line prior to the MEA’s grant of a CON. The court noted that “the sequence in which the statutes were adopted meant that [the utility] was granted a certificate of corridor compatibility prior to, but contingent upon, the issuance of the certificate of need.” Id. at 326.
Strict application of the statute results in the conclusion that after September 30, 1975, the MEQB lacked statutory authority to grant site designation to a plant which had not been granted a CON.6 However, in April 1976, NSP did successfully establish need for the Sherco 3 and 4 facilities to the MEA’s satisfaction. Had the MEQB withheld a decision on the Certificate of Site Compatibility pending the MEA’s grant of a CON, the Certificate of Site Compatibility would then have been granted. Putting aside the inaccuracy, later discovered, of NSP’s demand forecast, the utility did comply with the spirit of the regulatory scheme. We cannot conclude that the fact that the Certificate of Site Compatibility was granted before the CON was issued renders it invalid in this case.
The second prong of plaintiffs’ argument is that the Certificate is void by operation of law because it was issued “prior to, but contingent upon”, the grant of a CON.
Plaintiffs argue that when the MEQB revoked the CON as to Sherco 4 and as to the timing of Sherco 3, the Certificate of Site Compatibility issued in November 1975 was rendered invalid.
In his March 23, 1978, decision, the director of the MEA considered NSP’s request for a change in the in-service date of Sherco 3 to 1983 and of Sherco 4 to 1987.7 He noted that NSP had reduced its demand forecast because of slowed economic growth but had failed to provide specific information explaining the change. Regarding Sherco 3, NSP satisfied the director that the MEA’s previous determination of need with respect to the size and type of facility remained valid even if the in-service date for that facility was extended to 1984. Regarding Sherco 4, however, the director determined that this “further extension into the future” presented the possibility that changed technology and political and social factors would result in a change in the best size, type, and timing of the facility.8 He [585]*585ordered that the CON for Sherco 4 be voided but that, with regard to Sherco 3, “[t]he agency does not hereby relinquish its jurisdiction over that facility nor is the certification thereof voided; only that portion of the certification related to timing is voided.” On October 29, 1979, after rehearing on the timing issue, the MEA director established May 1,1985, as the in-service date for Sherco 3, a date which provided “additional time for thorough environmental review” of Sherco 3 alone.9
Plaintiffs argue that the MEA’s voiding of need certification for Sherco 3 as to timing invalidates the Certificate of Site Compatibility granted by the MEQB for that plant. The district court concluded that such a result would absurdly extend the language of No Power Line, which held the grant of site designation “contingent upon” the grant of a CON. We agree.
The procedures adopted by the legislature for the siting of power plants involve essentially a two-step process. First, a utility must obtain a CON from the MEA. See Minn.Stat. § 116H.13 (1978) (amended 1979, 1980). Second, the utility must obtain a Certificate of Site Compatibility from the MEQB. See Minn.Stat. § 116C.57 (1978). Once both of these Certificates have been issued, only three grounds exist upon which the Site Certificate can be declared invalid.
The first ground upon which a Site Certificate may be declared invalid is if one of the conditions specified in section 116C.645 occurs, such as if a utility makes a false statement in its application for a site or in other statements or studies required by the MEQB. See Minn.Stat. § 116C.645 (1978). The second ground upon which a Site Certificate may be declared invalid is if the utility fails to commence construction within four years of the issuance of the Certificate, see id. § 116C.62, and the MEQB determines that significant changes have taken place in the circumstances existing at the time the Certificate was issued. See 6 MCAR § 3.079A (1978). The final ground upon which a Site Certificate may be declared invalid is if it is determined that the hearing process failed to meet the statutorily mandated due process requirements. See In re Condemnation Proceedings for the Wilmarth Line of the C U Project, 299 N.W.2d 731 (Minn.1980). Unless one of these reasons exists, the Site Certificate must stand. Nothing in the record before this court indicates the existence of one of these three reasons.
The conclusion reached here is consistent with the legislative objective of siting “large electric power facilities in an orderly manner compatible with environmental preservation and the efficient use of resources.” Minn.Stat. § 116C.53, subd. 1 (1978). The process contemplated by the legislature recognizes the great length of time that the final approval of power plant construction takes. The injection of an additional ground for the reconsideration of site would only add time to an already lengthy process. It is obvious that at some point the siting process must be final and the utility must be allowed to construct the power plant in order to assure that the future energy demands of this state are met.
Laches
Appellants’ final contention is that the Site Certificate should be declared invalid because the MEQB failed to consider feasible and prudent alternatives before selection of the Sherco site. The district court held that the appellants were prevented by laches from attacking the Site Certificate on this basis. We agree with the district court.
Before an analysis is made of the facts that support a finding of laches in this case, it is important to note that the doctrine has [586]*586received a “lukewarm reception in suits presenting environmental questions * * *.'' MPIRG v. Butz, 498 F.2d 1314, 1324 (8th Cir. 1974). Nevertheless, when the plaintiff has been guilty of unreasonable delay and when this delay is shown to be prejudicial to the other party, federal courts have applied the laches doctrine in environmental cases. See Woida v. United States, 446 F.Supp. 1377, 1390-91 (D.Minn.1978); Organizations United for Ecology v. Bell, 446 F.Supp. 535, 552-53 (M.D.Pa.1978); Clark v. Volpe, 342 F.Supp. 1324, 1327-28 (E.D.La.), aff’d per curiam, 461 F.2d 1266 (5th Cir. 1972).
The district court found plaintiffs had been aware of the alleged defect in the Site Certificate at least since the Certificate was issued on November 10, 1975. Because no new facts had developed since that date, the district court held that plaintiffs’ four-year delay in bringing this suit was unreasonable. In finding prejudice to both NSP and the MEQB resulting from this delay, the district court stated:
[Sjince the certificate of site compatibility was issued in 1975, NSP and MEQB have continued through the permitting process. An EIS was prepared for which NSP contributed over $450,000. Hearings have been conducted by the MEQB at the various siting states and a rehearing on the in-service date for Sherco 3 has been completed. NSP and MEQB would be prejudiced if these efforts and expenditures of time and money were deemed wasted.
The trial court was correct in holding that laches was applicable to this cause of action. Plaintiffs should have challenged the alleged defects in the Site Certificate long before the filing of this suit. To allow a challenge based on omissions of the MEQB during the site hearings would prejudice the MEQB and NSP, both of which have invested extraordinary amounts of time and money in subsequent proceedings.
Affirmed.