OPINION OF THE COURT
Mollen, P. J.In these original proceedings pursuant to section 148 of the Public Service Law, petitioners challenge a determination of the New York State Board on Electric Generation Siting and the Environment (Siting Board), which authorized the Power Authority of the State of New York (PASNY) to construct a 700 megawatt fossil fueled power plant at Arthur Kill near Travis, Staten Island. Prior to reaching that determination, the Siting Board, pursuant to section 146 of the Public Service Law, was mandated to consider, inter alia, the public need for the facility, compatibility with public health and safety, whether “the facility is designed to operate in compliance with applicable state and local laws and regulations issued thereunder”, whether “the facility is consistent with long-range planning objectives”, and whether “the facility will serve the public interest, convenience and necessity”. However, pursuant to section 146 (subd 2, par [d]), the Siting Board can “refuse to apply any local ordinance, law, resolution or other action or any regulation issued thereunder or any , local standards or requirement which would be otherwise \ applicable if it finds that as applied to the proposed facility such is unreasonably restrictive.” PASNY filed its applica*348tion for authorization prior to July 1, 1978; therefore “a determination of necessity for [the] facility made by the power authority of the state of New York pursuant to section ten hundred five of the public authorities law [was] * * * conclusive on the board” (see Public Service Law, § 146, subd 2, par [f]).
On November 13, 1974, prior to filing its application with the Siting Board, PASNY adopted a resolution declaring that there was a public need for the facility. The Siting Board deemed this resolution conclusive on the question of public need and, after considering recommendations made by the State Energy Planning Board in March, 1980, concluded that the facility was also consistent with long-range planning objectives for electric power supply in the State. After considering the evidence presented at the hearing, the Siting Board concluded that the proposed facility’s impact on public health and the environment would be “acceptable”. With respect to local laws and regulations, the Siting Board concluded that PASNY, “as a state agency”, is exempt therefrom by virtue of sovereign immunity and “shifted to the City [of New York] the burden of explaining why specific provisions [i.e., local laws and regulations] should be imposed as certificate conditions.”
The primary issues before us are whether PASNY acted rationally when it determined that there is a public need for the facility, whether that determination was conclusive on the Siting Board, whether the Siting Board’s conclusion that construction and operation of the facility would be compatible with public health and safety is supported by substantial evidence, and whether the Siting Board’s analysis as to the application of local laws and regulations was proper. We conclude that PASNY’s determination that there is a public need for the proposed facility is reasonable and that that determination was conclusive upon the Siting Board. Further, since the Siting Board’s determination that the facility is compatible with public health and safety is rational and supported by substantial evidence, we will not substitute our judgment for the judgment of the Siting Board (see Public Service Law, § 148, subd 2). However, we reject the Siting Board’s conclusion that the City of New *349York bore the burden of proving that compliance with local laws and regulations should be imposed as a certificate condition. In our view, before issuing the certificate, the Siting Board is mandated, pursuant to section 146 (subd 2, par [d]) of the Public Service Law, to determine either that the facility is designed to operate in compliance with local laws and regulations or, in the alternative, that the local laws and regulations are unreasonábly restrictive. Since the Siting Board must make this determination before issuing a certificate of environmental compatibility and public need, the applicant, in this case PASNY, must bear the burden of proof on the issue. Therefore, we must remit this matter to the Siting Board for further consideration of applicable local laws and regulations.
I. THE FACTS
PASNY is a public authority, originally created in 1939 to develop hydroelectric power on the Niagara and St. Lawrence Rivers (see L 1939, ch 870). In 1972, the Legislature determined that “there is a shortage of dependable power capacity in the southeastern part of the state and that the public interest requires that the authority assist in alleviating such shortage by providing such base load generating facilities as may be necessary or desirable to contribute to the maintenance of an adequate and dependable supply of electricity for the metropolitan transportation authority, its subsidiary corporations, and the New York city transit authority” (see L 1972, ch 489, § 1, Public Authorities Law, § 1001). As a result, the Legislature authorized PASNY to “construct such base load generating facilities as it deems necessary or desirable to assist in maintaining an adequate and dependable supply of electricity” to these authorities (see L 1972, ch 489, § 2). In May, 1974, the Legislature further extended PASNY’s powers, authorizing it to construct, acquire and/or complete generating facilities to provide electrical power not only to the Metropolitan Transportation Authority and the New- York City Transit Authority, but also to the Port Authority, the City of New York, the State of New York, the United States, and other public corporations and electric corporations within the metropolitan area of the City of New York (see L 1974, ch 369, § 3). The Legislature also *350passed certain “emergency provisions” (see Public Authorities Law, § 1001-a):
“The legislature hereby finds and declares that extraordinary circumstances, including excessive costs, shortages of supply, and the inflated price of fuel threaten the capacity to provide utility service essential to the continued safety, health, prosperity and well-being of the people of the metropolitan area of the city of New York and, by reason of the interconnection and interdependence of electric facilities, the reliability of such service throughout the state and require emergency action by the state and its agencies. It is therefore declared that:
“1. To preserve reliability of electric service in the metropolitan area of the city of New York and throughout the state and to assist in deterring further extraordinary increases in rates for electric service the authority should provide such supplemental electricity for such use in the metropolitan area of the city of New York as is consistent with continuing and maintaining the exemption of interest on authority bonds from the income tax imposed by the Internal Revenue Code of the United States and regulations and ruling thereunder.
“2. It is essential that such electricity be provided at the earliest practicable time.
“3. The authority should be authorized to acquire completed or partially completed generation, transmission and related facilities and fuel and fuel contracts.
“4. Any cost savings realized in the production or delivery of electricity by reason of any such acquisition by the authority shall be passed on to consumers.”
Consistent with this legislation, PASNY adopted a resolution on November 13, 1974, which determined: “[T]here is a public need for the construction of base load generating facilities ‘to assist in maintaining an adequate and dependable supply of electricity by supplying power and energy, for the metropolitan transportation authority, its subsidiary corporations, the New York city transit authority, the port authority of New York and New Jersey, the city of New York, the state of New York, the United States, other public corporations and electric companies within the met*351ropolitan area of the city of New York within the state of New York, consisting of a 700 MW fossil fueled power plant adjacent to the Arthur Kill plant of Consolidated Edison Co. on Staten Island in Richmond County, New York”. On December 26, 1974, PASNY applied to the Siting Board for a certificate of environmental compatibility and public need. The application designated Arthur Kill as the preferred site for the new power plant, and designated Hart Island in New York City, the Quarry site in Dutchess County and the Athens site in Greene County as alternative sites.
Owing to certain “informational deficiencies” in the application, PASNY was required to submit certain amendments to its application. On September 20,1976, the Siting Board’s Chairman determined that the application, as amended, “now meets the minimum statutory requiremént for docketing.” However, PASNY requested additional time to submit another amendment. On October 29, 1976, PASNY submitted “Amendment No. 8 to its Application for a Certificate of Environmental Compatibility and Public Need”, and the application was docketed.
The hearing commenced on March 8,1977. On October 6, 1977, PASNY advised all parties to the proceeding that “the Hart Island alternative site is withdrawn from the Power Authority’s 700 MW fossil fuel application.” Thereafter, there were a number of delays initiated by parties opposed to the application. On or about January 13, 1978, after PASNY had submitted its direct case, and the other parties had nearly finished cross-examining PASNY’s witnesses, the New York State Department of Health (DOH) moved before the Siting Board for an order directing PASNY to conduct a 12-month study of the waters in and around Arthur Kill to ascertain the potential health risk arising from the proposed use of water from Arthur Kill in the operation of the on-shore natural draft cooling tower at the Arthur Kill Station. DOH explained that it failed to raise this point earlier because it lacked adequate staff and funding. The hearing examiner denied DOH’s motion, with leave to renew upon an evidentiary showing that the proposed operation of the cooling tower presented a health hazard. Thereafter, DOH and New York City submitted *352testimony on this question, and PASNY submitted rebuttal testimony. Ultimately, the Siting Board found that an additional 12-month study was not necessary as a precondition to certification. But in the meantime, on August 11, 1978, PASNY, at the request of various State and city public officials, commenced a re-evaluation of potential sites, in order to determine whether “another primary site in New York City, other than Arthur Kill, could be found” and, on November 13, 1978, the hearing was adjourned, pending that re-evaluation. Thereafter, PASNY submitted reports on three other viable sites in New York City, but the city was unable to agree on a preferred site. Therefore, PASNY elected to proceed with its application for approval of the Arthur Kill site, and the hearing resumed on November 27, 1979.
During the course of the hearing, PASNY took the position that the “finding of public necessity by the Power Authority is conclusive and that there is no reason to receive and consider information that formed the basis for the finding.” However, the New York State Energy Master Plan (SEMP), dated March, 1980, was admitted in evidence to establish that “the facility is consistent with long-range planning objectives for electric power supply in the state” (see Public Service Law, former § 146, subd 2, par [e]). SEMP reaffirmed the State’s need for new sources of power amounting to “approximately 1900 MW of new capacity beyond that already under construction, or approved for construction, to maintain adequate reserve margins over the forecast period.” SEMP also noted that “there is an overriding need in New York State to reduce oil dependence”; therefore, “[i]n addition to this required capacity [of 1900 MW], it is appropriate to include plans for approximately 2200-2700 MW of additional new capacity to reduce oil consumption.” SEMP specifically recommended construction of new generating plants in the downState area to alleviate the problem of “an over-dependence of oil-fired generation” and the strain on the transmission system in the Hudson Valley corridor, and mentioned Arthur Kill as a “feasible” location for a new facility.
There was extensive and conflicting testimony at the hearing with respect to the potential impact on health from *353fossil fuel combustion products and from cooling tower emissions.
The main boiler of the generating facility will burn both refuse and coal. PASNY’s application included data compiled by the Environmental Protection Agency (EPA), which analyzed the emissions from a refuse-burning plant in St. Louis. The EPA data indicated that emissions of sulfur oxides, hydrocarbons, carbon monoxide, mercury vapor or chlorine do not change appreciably with the supplemental burning of refuse. Further, it was established at the hearing that the emissions from the burning of coal will be in compliance with State and Federal air quality laws and regulations. However, the emissions of sulfur oxides, nitrous oxides, cadmium, beryllium and mercury will exceed the limits set by New York City’s air pollution control code. There was also testimony at the hearing that New York City’s emission standards, if enforced, would prevent the operation of any coal-fired electric generating power plant within the geographical boundaries of New York City.
Doctors Lester Bernard Lave and Warren Winkelstein, testifying on behalf of DOH, expressed the opinion that the proposed coal-fired plant will cause an increase in the death rate of the Staten Island population of 0.175 per 100,000 per year and an increase in the death rate of the rest of the New York City population of .0808 per 100,000. Dr. Winkelstein testified that “[t]he increased incremental risk to the individual due to the emissions of the plant is going to be the same no matter where the power plant is sited, but the risk to the population depends entirely upon the size of the population and its characteristics”. Adopting the position that there was no absolutely “safe” threshold dose of toxic emissions, Dr. Winkelstein pointedly noted: “[SJociety has to make a decision as to how much risk they’re willing to assume, and it seems to me that people should recognize that there will be some risk from putting up a power plant, although that doesn’t mean that they shouldn’t be built. One can’t build a highway without assuming a certain amount of risk or do anything without some risk.”
*354PASNY presented evidence that toxic emissions will be below threshold levels and will not have a detectable adverse health effect on the Staten Island community. Dr. Frederick Lipfert, testifying on behalf of the Department of Public Service, estimated that the emissions from the proposed facility will increase the risk of death on Staten Island by .0621 per million.
A natural draft cooling tower is proposed for this facility, which will use 222,000 gallons of Arthur Kill water per minute to cool the generators. PASNY estimated that 5,700 gallons or 2.6% of this water will be lost to evaporation, and another 11 gallons per minute would be released into the air in small droplets, known as “drift”. Thus, the effect of the discharge of these droplets on air quality is significant. PASNY tested the water for fecal coliform and chemical content over a 12-month period, but did not attempt to identify specific pathogenic microorganisms or viruses.
DOH’s witnesses, using a “worst case” assumption of 46,350 viruses per 100 milliliters of water, estimated that the cooling tower could disperse one infectious unit per 14,400 liters of air at the maximum point of impact. Based upon these estimates, DOH urged that PASNY conduct another 12-month study to ascertain the actual viral content of Arthur Kill water.
In response to DOH’s contentions, PASNY presented its own “worst case” analysis. Dr. Mark Sobsey estimated the “worst case” as 100,000 infectious units per liter of raw sewage, “[b]ecause this value is about twice the maximum value that has been reported in the literature for U.S. raw sewage”, and 10,000 infectious units per liter of unconcentrated water, because “[t]his value is 62.5 times the maximum concentration for a marine water reported in the scientific literature.” Assuming that the water in the cooling tower consisted of one part raw sewage and 24 parts water, Dr. Sobsey estimated that the maximum concentration of infectious units per liter of water in the cooling tower would be 13,600. At that rate, a person standing at the maximum point of concentration, 1.3 miles from the tower, would be exposed to one virus every 50 days. However, Dr. Sobsey noted that samples of unconcentrated *355Arthur Kill water taken on May 15, 1978 contained a maximum concentration of only 1.8 infectious units per liter. Assuming that the number of infectious units in peak season, late summer and early fall, is 100 times that, or 180 infectious units per liter of unconcentrated water* the cooling tower drift would contain only 5,842 infectious units per liter, which “is only about one-third the ground level virus concentration derived from a worst case analysis”.
In rebuttal, Dr. Joseph L. Melnick, testifying on behalf of petitioner Guy V. Molinari, estimated the “worst case” concentration at 1.8 million viruses per liter of raw sewage. Dr. Melnick based his estimate upon studies conducted in, inter alia, South Africa and Israel, and acknowledged that the average enteric virus density for sewage in the United States has been estimated at 7,000 plaque-forming units per liter. Dr. Stephen J. Millian, testifying on behalf of the New York City Department of Health, also claimed that Dr. Sobsey underestimated the “worst case”. Dr. Millian estimated the “worst case” in nonepidemic years as 219,500 plaque-forming units (which may consist of several infectious units) per liter of raw sewage. His colleague, William B. Pressman, estimated that the cooling tower water would contain 9% raw sewage, and, based upon his estimate, Dr. Millian calculated the “worst case” of viral concentration in the cooling tower makeup water as 39,730 plaque-forming units per liter, nearly three times Dr. Sobsey’s estimate of 13,600 plaque-forming units per liter. However, additional testimony revealed that Pressman had estimated the per cent of raw sewage in the water based upon an incorrect calculation of the amount of raw sewage pouring from the Victory outfall. Pressman’s calculations and, in turn, Dr. Millian’s calculations, were based upon the assumption that 1,800 gallons of raw sewage flowed from the Victory Boulevard outfall per minute. In fact, the Victory Boulevard outfall had a maximum capacity of 1,180 gallons per minute, while the Public Service Commission estimated the actual flow at 122 gallons per minute.
DOH also asserted that the cooling tower could present a risk to public health by dispersing toxic organic chemicals. *356However, based upon data compiled by the Environmental Protection Administration, and its own sampling, PASNY estimated that the chloroform concentration in the air dispersed by the cooling tower would be l/3000th of the occupational threshold limit value for chloroform. Concentrations of benzopyrene would be similarly insignificant. In rebuttal, Dr. Paul Margolin, on behalf of the City of New York, testified that he tested samples of Arthur Kill water which displayed a high degree of mutagenic activity, which indicates the presence of carcinogenic substances. However, those results were unreliable because chloroform had been added to the samples to kill background microorganisms.
In addition to releasing “drift”, the cooling tower will also discharge 14,300 gallons of water per minute (6.4% of the water flow) back into Arthur Kill as blowdown. Therefore, PASNY sought a waste water discharge permit, and presented evidence that the discharge would not appreciably affect the temperature of the water, nor the concentration of pollutants. PASNY’s witnesses estimated that at points 100 feet from the discharge, the temperature of the water would rise only 1.5 degrees Fahrenheit, which would constitute only .5% of the heat emanating from industrial sources at Arthur Kill. Since water will be lost in the cooling tower, owing to “drift” and evaporation, “fconstituents originally in the intake water will be concentrated about 1.4 times” in the discharge. However, the discharge will undergo “rapid diffusion”. A witness called by the City of New York testified that the cooling tower would have an adverse effect on dissolved oxygen, but that conclusion was contrary to testimony from PASNY’s expert, Grace Ekman, that operation of a natural draft cooling tower would improve the level of dissolved oxygen at Arthur Kill.
In its decision granting PASNY’s application for a certificate of environmental compatibility and public need, the Siting Board declined to make an independent determination of public need “because Section 146 (2) (f) of the Public Service Law says that a determination of necessity for a facility by PASNY shall be conclusive on the Siting Board.” However, the Siting Board noted that the Arthur Kill facility would “provide part of the 1900 MW [mega*357watts] of new capacity the Energy Planning Board found necessary to maintain adequate reserve margins during the 1979 through 1994 planning period.” Further the Siting Board held: “It is undisputed that reducing downstate reliance on oil-fired generating capacity is a desired objective and a primary feature of the State’s long-range energy plans. It is also clear that certification of the facility will have the advantageous effect of improving the generation mix available downstate independent of the conversion of existing oil-fired facilities to coal.”
On the public health issues, the Siting Board determined “[a]fter giving due weight to the various studies presented * * * the facility’s likely impact on public health in New York City and the surrounding area is acceptably small, and will be outweighed by the plant’s benefits.” Nevertheless, the Siting Board imposed certain conditions to insure that the “acceptable” risk to health would be further reduced. PASNY was directed to submit a plan for funding the closing of the Victory Boulevard outfall, to reduce the amount of raw sewage in the Arthur Kill waters. PASNY was also required to “provide treatment of the cooling tower makeup water to achieve the State’s highest microbiological standards for salt water from which edible shellfish can be taken.” The Siting Board ordered PASNY to conduct a one-year monitoring program of the “microbiological and chemical content of the Arthur Kill”, to determine the specific design for the water treatment program. PASNY’s application for a wastewater permit was also subject to “effluent limitations, monitoring requirements and other conditions” to insure the attainment of water quality commensurate with Arthur Kill’s status as a class “SD” and class B-2 waterway.
In their proposed findings, the hearing examiners concluded that PASNY was generally exempt from local laws and regulations, because, pursuant to section 1014 of the Public Authorities Law, it is an instrumentality of the State performing a governmental function. However, the examiners believed that section 146 (subd 2, par [d]) of the Public Service Law “requires the Siting Board, as a condition of certification to find that the facility is designed to operate in compliance with applicable state and local laws *358in the area of the environment, public health and safety unless waived by the Board as unduly restrictive as applied to the proposed facility * * * Clearly, ‘applicable’ refers to substance, that is state and local laws and regulations dealing with, among other matters, the environment, public health and safety — the areas with which Article VIII is substantively concerned.” Although the Siting Board accepted the position that PASNY is generally exempt from local laws and regulations, it rejected the examiners’ conclusion that section 146 (subd 2, par [d]) of the Public Service Law requires a consideration of local laws and regulations. Nevertheless, the Siting Board acknowledged that “many of the City’s standards deal with subjects of serious concern”. Thus, PASNY was directed to comply with local fire regulations. Further, the Siting Board felt compelled to hold that “New York City air quality standards for sulfur dioxide, nitrogen oxides, cadmium, beryllium, and mercury are unreasonably restrictive in view of existing technology and costs to consumers”. The Siting Board also permitted New York City to submit a “list of local standards it wishes to have applied as certificate conditions, along with justification for its requests.” However, in the order denying petitions for rehearing, the board rejected New York City’s submissions, holding that New York City has “the burden of explaining why specific provisions should be imposed as certificate conditions.”
II. PUBLIC NEED
The Siting Board was created by the Legislature in 1972 “to provide for the expeditious resolution of all matters concerning the location of major steam electric generating facilities * * * in a single proceeding * * * to which access will be open to citizens, groups, municipalities and other public agencies to enable them to participate in these decisions” (see L 1972, ch 385, § 1). At that time, the Legislature made certain policy statements, inter alia (see L 1972, ch 385, § 1): “[Tjhere is at present and may continue to be a growing need for electric power and for the construction of new major steam electric generating facilities. At the same time it is recognized that such facilities cannot be built without in some way affecting the physical environment where such facilities are located, and in some *359cases the adverse effects may be serious. The legislature further finds that it is essential to the public interest that meeting power demands and protecting the environment be regarded as equally important and that neither be subordinated to the other in any evaluation of the proposed construction of major steam electric generating facilities. Without limiting the generality of the foregoing, the legislature finds and declares that under certain circumstances power demands may be regarded as controlling even though the adverse environmental impact may be substantial, but that under other circumstances, given the nature of the resource involved and the public interest in preserving and enhancing the quality of life, the protection of the environment may be regarded as controlling even though this might result in restrictions on the availability of public utility services.” Based on these considerations, the Legislature enacted former article 8 of the Public Service Law, setting forth the procedure to be followed by the Siting Board. Before issuing a certificate of environmental compatibility and public need the Siting Board was required to find and determine, inter alia, “the public need for the facility and the basis thereof” and “that the facility will serve the public interest, convenience, and necessity, provided, however, that a determination of necessity for a facility made by the power authority of the state of New York pursuant to section ten hundred five of the public authorities law shall be conclusive on the board” (see L 1972, ch 385, § 2, Public Service Law, former § 146, subd 2, pars [a], [f]).
In 1977, the Legislature attempted to repeal that portion of section 146 (subd 2, par [f]) of the Public Service Law which provided that “a determination of necessity for a facility made by the power authority of the state of New York * * * shall be conclusive on the board”, but that repeal was vetoed by the Governor. In his veto message, the Governor stated that authorizing the Siting Board to make an “independent determination of the need for any facility proposed to be constructed by PASNY” could impair the contract rights of PASNY’s bondholders and would unnecessarily protract hearings already underway (see 4 NY Assembly J 5203 [200th Session, 1977]).
*360In 1978, former article 8 of the Public Service Law was repealed in its entirety, and superseded by the present version (see L 1978, ch 708, § 2), which mandates that the Siting Board make an independent determination with respect to “public interest, convenience and necessity,” but with the proviso that “a determination of necessity for a facility made by the power authority of the state of New York pursuant to section ten hundred five of the public authorities law for which an application for a certificate has been filed prior to July first, nineteen hundred seventy-eight shall be conclusive on the board” (see Public Service Law, § 146, subd 2, par [f]). Simultaneously therewith, the Legislature added section 5-112 (subd 3, par c) to the Energy Law to provide that “on and after January first, nineteen hundred eighty, the specific findings of projected electric demands for the forecast periods in the [energy planning] board’s report shall be binding on the [Siting Board]”.
In the instant proceeding, one of the petitioners, Elizabeth Connelly, contends that the only finding by PASNY which can be binding on the Siting Board is a finding of “public necessity”. Ms. Connelly argues further that even if the PASNY resolution of November 13, 1974 constitutes such a finding of “public necessity”, the board was obligated by law to go further and determine for itself whether there is a “public need” for the particular facility proposed. We find no merit in this contention because, in our view, if a particular generating facility will serve “public necessity”, a fortiori, there must be a “public need” for new generating power. We note that, in an analogous proceeding pursuant to article 7 of the Public Service Law, PAS-NY’s determination of need was deemed binding on the Public Service Commission because “PASNY, unlike most other power utilities across the State, is a State agency and it would be a duplication of efforts to require two State agencies to make an identical determination, a procedure that could be fraught with ambiguities should each agency reach opposite conclusions” (see Atwell v Power Auth. of State of N. Y., 67 AD2d 365, 374).
The legislative history of article 8 of the Public Service Law also indicates that the Legislature intended that *361PASNY’s determination with respect to need would be conclusive on the Siting Board if, as in the instant case, the application was filed before July 1,1978. Where the practical construction of a statute is known to the Legislature, its failure to interfere indicates acquiescence (see Engle v Talarico, 33 NY2d 237, 242; RKO-Keith-Orpheum Theatres v City of New York, 308 NY 493, 500). In this instance, the Legislature was clearly aware that “public necessity” was being construed as synonymous with “public need”, as borne out by the Governor’s veto message in 1977. In 1978, the Legislature did interfere, but not with respect to applications filed prior to July 1, 1978. Presently, as to applications filed subsequent to July 1, 1978, the Siting Board is required to make an independent determination of need, but if, as in the instant case, PASNY filed the application prior to July 1, 1978, PAS-NY’s determination is conclusive on the Siting Board (see Public Service Law, § 146, subd 2, par [f]).
However, PASNY’s resolution of need is an integral part of the Siting Board’s decision, reviewable by this court pursuant to section 148 of the Public Service Law (see Atwell v Power Auth. of State of N. Ysupra). Certain legislative findings enacted in 1972 and 1974 (see L 1974, ch 369, § 2, Public Authorities Law, § 1001-a; L 1972, ch 489, § 1) shed light on this issue. The Temporary State Commission on Environmental Impact of Major Public Utility Facilities, in its final report to the Legislature, noted that new generating capacity was needed in the State and, further, that Consolidated Edison might be-unable to meet summer load requirements in New York City because of an “inability to locate and place in service large generating units in or adjacent to its service area because of environmental controversies.” Thereafter, the Legislature determined, inter alia, that “there is a shortage of dependable power capacity in the southeastern part of the state” (see L 1972, ch 489, § 1), and in 1974 found, inter alia, that “extraordinary circumstances, including excessive costs, shortages of supply, and the inflated price of fuel threaten the capacity to provide utility service essential to the continued safety, health, prosperity and well-being of the people of the metropolitan- area of the city *362of New York” (see Public Authorities Law, § 1001-a, L 1974, ch 369, § 2). PASNY’s resolution of November 13, 1974 reiterated the findings of the Legislature. Therefore, that resolution cannot be deemed arbitrary, capricious, or lacking in evidentiary support (see Public Service Law, § 148, subd 2, pars [b], [e]).
The City of New York contends, however, that PASNY’s resolution is stale and no longer valid on the basis of a change in circumstances. Although the proceeding before the Siting Board proceeded interminably for more than seven years, PASNY’s adversaries were partially responsible for this delay. Therefore, the delay alone would not be a sufficient reason to remit the matter to PASNY for reconsideration of the question of need. Were it otherwise, obviously, an endless cycle would ensue as a result of the required Siting Board proceedings and the consequent delays thereby engendered. Further, the State Energy Master Plan (SEMP), dated March, 1980, which was introduced in evidence at the hearing, refutes the city’s contention that there has been a significant change of circumstances. SEMP specifically recommended construction of new generating plants in the down-State area to alleviate the problem of overdependence on oil and the strain on the transmission system in Hudson Valley. SEMP also declared that the State needed 1,900 MW of new generating capacity to meet projected electric demands. Pursuant to section 5-112 (subd 3, par c) of the Energy Law, that finding was binding on the Siting Board, which noted in its decision that the Arthur Kill facility would “provide part of the 1900 MW of new capacity the Energy Planning Board found necessary”. Since PASNY’s resolution of need was reaffirmed in substance as recently as March, 1980, the city’s contention that that resolution is no longer valid is without merit.
III. COMPATIBILITY WITH PUBLIC HEALTH AND THE ENVIRONMENT
After considering all of the evidence and the recommendation of, inter alia, the Department of Environmental Conservation, the Public Service Commission and the De*363partment of Health,1 and the arguments of petitioners Guy Molinari and the City of New York, the Siting Board concluded that the proposed generating facility at Arthur Kill “will have acceptable impacts on the environment and on public health”.
Petitioners challenge the sufficiency of the evidence with respect to compatibility with public health and the environment. Petitioner Connelly asserts that “[t]he record is inadequate with regard to the environmental effects of burning RDF [refuse derived fuel]”. Although PASNY’s application included data from an EPA study of a prototype plant in St. Louis, indicating that toxic emissions do not change appreciably with the supplemental burning of refuse, petitioner Connelly claims that this was not sufficient, “without proof or substantiation that the effects of burning RDF produced in New York City will be substantially the same as for RDF produced in St. Louis.” It is also asserted that insufficient empirical data was submitted to the Siting Board. The City of New York points to the condition in the certificate of environmental compatibility and public need, mandating that PASNY conduct a 12-month monitoring program subsequent to certification, as evidence that “uncertainties” exist which should be resolved prior to certification.
However, it can always be argued that more could have been done. In the instant case, PASNY analyzed the available data, and monitored the water at Arthur Kill for a 12-month period to determine fecal coliform and chemical content. PASNY took additional samples in May, 1978 to determine viral content. The Siting Board did not find that additional empirical studies were necessary. The board specifically found that the “risk from * * * use of the Arthur Kill waters is acceptable” and ordered an additional 12-month monitoring program, not because “this study is necessary for purposes of finding the plant’s emissions acceptable,” but rather, to “provide useful information for the specific design of the cooling system water *364treatment program that PASNY is required to submit” in order to reduce that risk still further.2
This court’s scope of review is limited to whether the decision and opinion of the board, inter alia, are, “supported by substantial evidence in the record and matters of judicial notice properly considered and applied in the opinion” (see Public Service Law, § 148, subd 2, par [b]), are made in accordance with proper procedure (par [d]) and are not “arbitrary, capricious or an abuse of discretion” (par [e]). A determination is supported by substantial evidence if it is supported by “such relevant proof as a reasonable mind may accept as adequate to support a conclusion or ultimate fact” (see 300 Gramatan Ave. Assoc. v State Div. of Human Rights, 45 NY2d 176, 180). The Siting Board’s decision sets forth relevant and probative evidence to support each of its conclusions. On the question of viral emissions from the cooling tower, the Siting Board adopted the analysis of the Public Service Commission, which relied in part on Dr. Millian’s estimate of the viral content of raw sewage, and also considered other factors, including the fact that some viruses would be inactivated by exposure to heat and sunlight. Based on this analysis, the Siting Board determined that the risk presented was acceptably small. Further, the board credited the testimony submitted by PASNY that the risk posed by other pollutants dispersed by the cooling tower was small enough to be insignificant. With respect to emissions from the main boiler, the board noted that even the objectors found the health risk to be “relatively small”. The board acknowledged that the proposed facility would create some risk to public health, but determined that those risks would be outweighed by the benefits. Although obviously petitioners would prefer a no-risk situation, that standard may well be impossible to attain. As Dr. Winkelstein, testifying on behalf of DOH, aptly put it, “[o]ne can’t * * * do anything without some risk.” The Legislature has delegated to the Siting Board the authority to balance the risks against the benefits, and, unless that authority is exercised in an arbitrary or capri*365cious manner, this court will not substitute its judgment for that of the Siting Board.
The Siting Board, however, in reaching its determination is obliged to consider each of the factors set forth in section 146 of the Public Service Law. Petitioners assert that the Siting Board failed to adequately consider “possible available sites or alternative available sources of energy * * * and totality of the needs of the people of the state for the facility within the context of the need for public utility services and for protection of the environment” (see Public Service Law, § 146, subd 2, par [g]). Petitioners further urge that the board failed to adequately consider whether the facility is consistent with long-range planning for the protection of the environment, as well as for reliable electric power (see Public Service Law, § 146, subd 2, par [e]). Petitioners also specifically claim that the proposed facility will discharge effluents from its cooling tower “in contravention of the standards adopted by the department of environmental conservation” (see Public Service Law, § 146, subd 2, par [c]). Moreover, petitioners assert that the board acted improperly when it concluded that PASNY was exempt from local laws and regulations, and shifted the burden of proof onto the City of New York to establish “why specific provisions should be imposed as certificate conditions.”
The Siting Board’s opinion and order discusses alternative sources of energy in detail. As was noted in SEMP, the construction of a plant down-State would alleviate New York City’s overdependence on oil, and the strain on the transmission system in the Hudson Valley corridor. Therefore, purchase of Canadian power, which would require use of the “northern transmission corridor,” would be an inadequate alternative. SEMP also reaffirmed the State’s need for additional generating power; therefore, the conversion of existing facilities to coal would also be an inadequate alternative. The City of New York contends that the Siting Board should have considered “the cumúlative impacts of the'proposed plant and the five coal conversions planned for in the State Energy Master Plan.” However, the Siting Board noted that “there are obstacles in the path of conversions, and how many will ultimately be completed remains *366uncertain.” The question of whether an environmental obstacle to potential coal conversions exists should be determined at the time the additional conversions take place, rather than in this proceeding.
The Siting Board also gave adequate consideration to alternative sites, and concluded that “air quality and public health considerations favor Athens or Quarry over Arthur Kill,” but “the Arthur Kill site is clearly superior to Athens or Quarry from the standpoint of terrestrial ecology, land use, visual and aesthetic considerations, aquatic ecology, water quality and quantity, transmission considerations, and potential noise impact.” The Arthur Kill site was also preferred because it is located down-State. The City of New York challenges the sufficiency of these findings, because PASNY did not submit evidence on the health impact of a natural draft cooling tower at the two up-State sites. However, PASNY was not required to “make detailed and expensive studies of every conceivable alternative” (see Tyminski v Public Serv. Comm. of State of N. Y., 38 NY2d 156, 160), and properly concentrated its attentions on the primary site. In any event, the Siting Board acknowledged that public health considerations favored Athens or Quarry over Arthur Kill, but concluded that this factor was outweighed by other considerations prescribed by the Legislature in section 146 of the Public Service Law.
With respect to the effluent from the cooling tower, PASNY applied for and was granted a wastewater discharge permit. During the course of the hearing, the parties misclassified Arthur Kill as a class II waterway (see 6 NYCRR 702.3), while the Siting Board noted that the Arthur Kill “in the area of the facility * * * has been reclassified as a Class SD waterway.” Class SD waterways must contain not less than 3.0 mg/1 of dissolved oxygen at any time (see 6 NYCRR 701.5). Thus, one of the conditions imposed in the permit was that “discharges shall be limited so that the attainment [of that standard] * * * will not be prevented”. In any event, PASNY submitted evidence that operation of the cooling tower would improve the level of dissolved oxygen. On the question of thermal pollution, there was testimony that the temperature at 100 *367feet from the point of discharge would only rise 1.5 degrees Fahrenheit. Although the blowdown at impact “can be relatively high (94° F) maximum”, PASNY’s experts assured the Siting Board that the heat would dissipate rapidly, and not harm aquatic life. Unfortunately, the Arthur Kill waters are not in compliance with State regulations governing thermal discharges into estuaries (see 6 NYCRR 704.2 [b] [5]). Therefore, PASNY sought a variance from those criteria (see 6 NYCRR 704.4). On that point, there was testimony that the blowdown from the cooling tower will only be responsible for 0.5% of the heat emanating from industrial sources at Arthur Kill. Thomas E. Quinn, of the Department of Environmental Conservation, and Fred W. Ulrich, of the Department of Public Service, did not believe that this “will contribute materially to this violation or will interfere with the efforts underway to bring the Arthur Kill waters into conformance with these water quality standards.” Thus, the Siting Board concluded that the facility “will not discharge any effluent that will be unduly injurious to the propagation and protection of fish and wildlife, the industrial development of the State, and the public health and public enjoyment of the receiving waters.”
Incongruously, the City of New York contends that the Siting Board erred when it “failed to include effluent limitations for pollutants” which do not originate from the facility, but which are already in the intake waters. Since some of the water will be lost to evaporation and “drift”, the constituents in the water discharged will be concentrated 1.4 times their original levels. The City of New York is concerned that additional concentrations of raw sewage and fecal coliform would be injurious to the environment, yet it continues to disperse this raw sewage into the water in the first instance. PASNY is not responsible for this raw sewage, and is not required to reduce the level of pollutants which it does not create (see Appalachian Power Co. v Train, 545 F2d 1351). Nevertheless, PASNY was ordered, as a condition to certification, to close the Victory Boulevard outfall, thus, to some extent, curtailing the level of pollutants. Further, the fact that the cooling tower will alter the concentration of pollutants (see ECL 17-0509) *368was considered by the Siting Board, which noted that “the design of the discharge structure provides for a quick return to ambient concentrations.” Therefore, the city’s contentions are without merit.
IV. COMPLIANCE WITH LOCAL LAWS AND REGULATIONS
PASNY is “a body corporate and politic, a political subdivision of the state, exercising governmental and public powers, perpetual in duration” (Public Authorities Law, § 1002). Therefore, PASNY has asserted throughout these proceedings that it is exempt from the requirements of subdivision 2 of section 146 of the Public Service Law, which insofar as is pertinent herein, provides as follows:
“2. * * * The board may not grant a certificate for the construction or operation of a major steam electric generating facility, either as proposed or as modified by the board, unless it shall first find and determine * * *
“(d) that the facility is designed to operate in compliance with applicable state and local laws and regulations issued thereunder concerning, among other matters, the environment, public health and safety, all of which shall be binding upon the applicant, except that the board may refuse to apply any local ordinance, law, resolution or other action or any regulation issued thereunder or any local standards or requirement which would be otherwise applicable if it finds that as applied to the proposed facility such is unreasonably restrictive in view of the existing technology or the needs of or costs to consumers whether located inside or outside of such municipality. The board shall provide the municipality an opportunity to present evidence in support of such ordinance, law, resolution, regulation, or other local action issued thereunder.” (Emphasis supplied.)
As a governmental body, PASNY is exempt from local laws and regulations so long as it is performing a governmental as distinguished from a proprietary function (see County of Westchester v Village of Mamaroneck, 22 AD2d 143, affd 16 NY2d 940; City of Rochester v Town of Rush, 67 Misc 2d 328, affd 37 AD2d 795; Conners v New York State Assn. of Retarded Children, 82 Misc 2d 861; People v Witherspoon, 52 Misc 2d 320). The operation of an electrical power plant may once have been considered a proprietary function (see *369Matter of Village of Boonville v Maltbie, 245 App Div 468, affd 272 NY 40). However, “the demarcation between governmental or proprietary interests in property owned or operated by government or its subdivisions [is] no longer * * * as clear as it was in the past” (see County of Nassau v South Farmingdale Water Dist., 46 NY2d 794, 796; Nehrbas v Incorporated Vil. of Lloyd Harbor, 2 NY2d 190; People v Witherspoon, supra). Governmental functions are now more liberally defined to include activities which are not undertaken for profit-making purposes, but, rather, as a public duty (see County of Nassau v South Farmingdale Water Dist., 62 AD2d 380, affd 46 NY2d 794, supra). In this instance, the Legislature determined that the private sector lacked sufficient resources to insure a dependable supply of electricity in the New York City metropolitan area, and delegated to PASNY the authority to alleviate what it characterized as “extraordinary circumstances” (see Public Authorities Law, § 1001-a). Thus, the Legislature has seen fit to characterize the construction and operation of electrical power plants as a public governmental function.
But that does not conclude our inquiry. When the Legislature created the Siting Board in 1972, it amended section 1014 of the Public Authorities Law to provide that PASNY was subject to the provisions of article 8 of the Public Service Law (see L 1972, ch 385, § 3), including section 146 (subd 2, par [d]). Section 146 (subd 2, par [d]) specifically states that the applicant is bound by “applicable” laws and regulations. Article 8 of the Public Service Law and the conforming amendment to section 1014 of the Public Authorities Law were enacted subsequent to section 1002 of the Public Authorities Law and for a specific purpose. Therefore, pursuant to general rules of statutory construction, these provisions take precedence over section 1002 of the Public Authorities Law, which is general in scope and application (see Matter of Martinis v Supreme Ct. of State of N. Y., 15 NY2d 240, 249; McKinney’s Cons Laws of NY, Book 1, Statutes, § 397).
However, PASNY contends that the Legislature, by using the word “applicable,” intended to exempt PASNY from that provision, because local enactments, by virtue of sovereign immunity, are not “applicable” to PASNY. If *370that were the Legislature’s intent, it certainly could have expressed it in clearer language, such as the explicit language in former section 146 (subd 2, par [f]), that “a determination of necessity for a facility made by the power authority of the state of New York pursuant to section ten hundred five of the public authorities law * * * shall be conclusive on the board”. In the absence of similarly explicit language in present section 146 (subd 2, par [d]), PASNY’s argument is tenuous at best, and contradicted facially by the actual language of that section.
When article 8 of the Public Services Law was first enacted in 1972 (L 1972, ch 385), the Governor, in his memorandum in support of the bill, noted that “[l]ocal ordinances and regulations would also be applied except where they were expressly and specifically found to be unreasonable” (see NY Legis Ann, 1972, pp 248, 251). No mention is made of any exemption from this provision, nor can PASNY point to any reference to such claimed exemption from any other source. Instead, PASNY must rely on the conclusion of the Siting Board, that local laws and regulations were not “applicable” to the proposed facility because PASNY is the applicant. Since the Siting Board has been entrusted with the implementation of article 8, its interpretation of section 146 (subd 2, par [d]) is entitled to respect, but it is by no means dispositive (cf. Matter of Lezette v Board, ofEduc., 35 NY2d 272, 281).
PASNY claims that article 8 is merely a forum statute and not a substantive statute. However, this characterization cannot withstand close scrutiny. The Siting Board was created to “provide for the expeditious resolution of all matters * * * in a single proceeding”, but was also created to permit a broad participation in such proceedings by citizens and citizen groups, as well as by municipalities and other public agencies (see L 1972, ch 385, § 1). As an umbrella agency, the Siting Board has duties which could not be performed by any of the diverse agencies whose functions it has assumed. It must balance the need for the facility against environmental considerations, and determine “that the facility is consistent with long-range planning objectives for electric power supply in the state, including an economic and reliable electric system; and for *371protection of the environment” (see Public Service Law, § 146, subd 2, par [e]). The very provision in question contains elements which are plainly substantive, e.g., the Siting Board may determine that a local requirement is “unreasonably restrictive in view of the existing technology or the needs of or costs to consumers” (see Public Service Law, § 146, subd 2, par [d]).
Although the Siting Board concluded that PASNY was exempt as a matter of law from local laws and regulations, it found the question of the application of the local laws and regulations rather troublesome. The board recognized that “many of [New York] City’s standards deal with subjects of serious concern”. Therefore, the board created a new ad hoc procedure, whereby the City of New York bore the burden of explaining why specific provisions of its local laws and regulations should be imposed. With respect to New York City’s Fire Prevention Code, the board found that the city had established “compelling reasons to condition a certificate for this plant upon PASNY’s adherence to the substance of the City’s Fire Prevention Code”, and directed that PASNY comply. However, the board rejected the city’s submission of additional laws and regulations, because “the City has not in fact satisfied its burden with its vague allusions to its ‘police powers,’ its interest in health and safety, and its suggestion that City laws and regulations contain ‘presumptively reasonable’ standards.” The board also held that New York City’s air quality standards are unreasonably restrictive, but in light of its determination that local laws and regulations were not “applicable” pursuant to section 146 (subd 2, par [d]), the board acted upon an erroneous assumption as to the burden of proof in reaching that determination.
The fact that the Siting Board thought it necessary to devise this ad hoc procedure for dealing with local laws and regulations underscores the problems with its interpretation of section 146 (subd 2, par [d]) of the Public Service Law. If local laws and regulations are not “applicable” pursuant to that provision, there is a gaping hole in article 8. Since the legislative intent was to create an all-encompassing procedure, there is clearly something wrong with this interpretation. The interpretation of the hearing ex*372aminers that “‘applicable’ refers to substance, that is state and local laws and regulations dealing with, among other matters, the environment, public health and safety — the areas with which Article VIII is substantively concerned”, is far more logical and consistent with the legislative history of article 8.
For these reasons, we hold that PASNY is not exempt from the requirements of section 146 (subd 2, par [d]) of the Public Service Law, and that the Siting Board’s determination on that question was erroneous. Thus, the determination of the Siting Board must be annulled, and the matter remitted to the Siting Board for a rehearing on the question of whether the proposed facility is designed to operate in compliance, with local laws and regulations, or, if not, that said local laws and regulations are unreasonably restrictive as applied to the proposed facility, with the burden of proof resting upon PASNY. The hearing should be reopened to give PASNY the opportunity to satisfy its burden of proof on these questions and to provide other parties the opportunity to be heard.3
In so holding, we do nothing more than give effect to the unambiguous intent of the subject legislation. Clearly this legislation reflects an effort to establish a rational balance between a program geared to best utilize the State’s resources in providing a sufficient and economical source of electricity and the need to insure that such program proceeds with a maximum recognition of the health, safety, environmental, ecological and other valid concerns of the local communities in which such facilities would be located. Both the legislative history and the Governor’s memorandum (see NY Legis Ann,' 1972, p 248) make abundantly clear the legislative intent to compel compliance with the local laws and regulations, except in those extraordinary instances where PASNY establishes that such local laws and regulations are unreasonable. Thus, it is not the city which bears the burden of proof, but PASNY which must demonstrate to the Siting Board that the local *373laws and regulations in question are unreasonably restrictive. Only in this way may the legitimate interests of a local community be furthered and protected as intended by the legislation.
Finally, we note that we are not unsympathetic to our distinguished dissenting colleague’s deep concern over the possible effects of the proposed power plant on the health and safety of the people of Staten Island. In our view, however, the approach taken by the dissenter is fundamentally inconsistent with our function on this appeal. He has carefully parsed the record, extracting all evidence which would militate against the granting of the application, and has presented it in an attempt to demonstrate that the application should have been denied. The task of weighing conflicting evidence, however, is properly left to the Siting Board. Our function on review is, as earlier stated, limited to determining whether the board’s decision is supported by substantial evidence in the record and whether it has been reached in accordance with proper procedure, rather than to substitute our judgment for that of the Siting Board.
Our review of the record in its entirety convinces us that the board’s determination was in fact supported by substantial evidence and, since we conclude that the only flaw in the proceedings was the improper allocation, as a matter of law, of the burden of proof with respect to the applicability of local laws and regulations, we adopt the remedy of remitting the matter to the Siting Board for a rehearing on that limited issue.
. The Commissioner of the State Department of Commerce and the Commissioner of the State Energy Office sat as voting members of the Siting Board and, therefore, participated in the decision-making process. Petitioner Connelly’s contention that they did not participate is without merit.
. PASNY has agreed to the imposition of this condition, and states in its brief that it “is committed to use this pretreatment to achieve the state’s Class SA water quality standard for the treated makeup water.”
. Petitioner Molinari’s contention that article 9 of chapter 57 of the New York City Administrative Code has been incorporated into the State implementation plan is not borne out by the record. However, on rehearing, said petitioner, if so advised, may submit additional material on this point.