Rosenberry, J.
The plaintiffs are residents, electors, property owners, and taxpayers, residing in the town of Greenfield, Milwaukee county, and within the limits of the proposed Metropolitan sewerage district, and bring the action in their own behalf and in behalf of all other property owners and taxpayers of Milwaukee county similarly situated.
[47]*47The first contention made on behalf of plaintiffs is that by the language of sub. 5 of sec. 1 of ch. 554, Laws 1921, reference is made to maps and surveys then in existence; that the maps and surveys referred to in the second finding of fact were prepared at the direction of the Milwaukee Sewerage Commission at a time subsequent to the passage and publication of ch. 554, and the action of the Metropolitan Sewerage Commission was not in compliance with the act.' There is nothing in the language of the act itself indicating that reference was had by the legislature to any existing maps or surveys. How could a map or survey be prepared which would form the basis of action by the Metropolitan Sewerage Commission in fixing and establishing boundaries of the proposed sewerage district unless and until the legislature had specified in general terms at least what territory should be included therein? The area to be embraced within the proposed district was “the portion of said county which is within the same drainage area as the sewerage system of such city of the first class, the sewage from which may be cared for by the disposal plant located in such city of the first class.” Manifestly, it was intended to include within the proposed district territory other than that within the natural drainage area within which the sewerage system of. the city of Milwaukee was situated, and to include therein such additional territory as might be cared for by the sewage disposal plant located in the city of Milwaukee. So whether the maps and surveys submitted to the Metropolitan Sewerage Commission by 'the Sezuerage Commission of the city of Milwaukee were made before or after the enactment of ch. 554 is immaterial, if they in fact did show the portion of the county which was within the same drainage area as the sewerage system of the city of Milwaukee, the sewage from which might be cared for by the disposal plant of the city of Milwaukee.
The trial court found that a portion of the territory [48]*48within the boundaries of the Metropolitan sewerage district at the present time consists largely of farming communities, with no large factories, and that there is at the present time no need of intercepting sewers. It is argued that the territory referred to in such finding will therefore receive no benefit from the construction of the proposed improvement and therefore no tax can be legally imposed upon it, citing State ex rel. Owen v. Donald, 160 Wis. 21 (151 N. W. 331), at p. 125. We do not think the conclusion reached by counsel necessarily follows from the facts stated in the finding. It is conceded that the territory in question is suburban in character. The court found that the Metropolitan Sewerage Commission considered the past, present, and prospective future growth and development of the cities, villages, and industries in the sewerage district and considered the necessity of planning and constructing a system of intercepting sewers which would be reasdnably sufficient in size and capacity to care for and handle the prospective needs of the district, and that in so doing the Commission exercised their best judgment and acted in good faith. How can it be said that no benefit accrued to the property owners in the territory to be served by the proposed sewerage system ? It may well be that the benefits will be more immediate and direct in some cases than in others. It is plain that to construct a system which would be sufficient to provide for present needs only would be little short of folly. When the great intercepting sewers are, once constructed their capacity cannot be enlarged excepting by rebuilding them at enormous expense or- paralleling them with a second system. The legislature required that provision be made so that as additional use develops by reason of the extension of manufacturing districts or increasing density of population, it may be provided for at a minimum of public expense. Looking at the matter in the light of experience and taking into consideration the reasonable probabilities of the future, it must be said that [49]*49the property embraced in the sewerage district receives a present benefit which fully justifies the exercise of the taxing power in this case. That matters of this kind should be dealt with in a large, comprehensive way, rather than in detail and piecemeal as the imperative necessity arises, seems apparent on a moment’s consideration.
By the fourth finding the trial court determined that all of the territory within the boundaries of the Metropolitan sewerage district as established by the Commission lies within the natural water-shed of the Milwaukee river, and its tributaries except certain districts referred to in sub. (a), (b), and (c) of the fourth finding. It appears from the evidence that in these instances certain territory is included, the sewage from which would be carried to the sewage disposal plant of the city of Milwaukee, although not within the natural drainage basin. In determining what the boundaries of the sewerage district should be, the Metropolitan Sewerage Commission proceeded in the exercise of a power clearly conferred upon them by ch. 554. We are in effect asked to review the finding of the trial court and to a certain extent the determination of the Metropolitan Sezverage Commission and to substitute our judgment for that of the Commission as to the location of the boundary line of the district. It must be borne in mind that in fixing the boundaries of the district wherever fixed, there would be property upon one side of the line which was erroneously placed. If the line were placed too close to the populous centers, territory would be excluded from the district which clearly belonged within it. If placed too far from the densely populated regions, territory would be included which perhaps, strictly speaking, did not belong in a sewerage district. The boundary line must be established somewhere, and for its establishment there must be some competent authority. The legislature in a general way fixed the boundaries of the district as before stated. The Sewerage Commission, as appears by the maps [50]*50and surveys in evidence, substantially complied with the legislative mandate. In some instances in following quarter-section lines so as to provide a workable scheme for the levying of the tax provided for in ch. 554, parts of quarter-sections were included which are not, strictly speaking, within the designated area. Other parts of quarter-sections were excluded which may, strictly speaking, be within the designated area. The Metropolitan Sezuerage Commission evidently followed with as much fidelity as is reasonably possible the legislative command in establishing the boundaries of the” district, and unless there is a substantial -departure from the legislative scheme we see no grounds upon which this court can or should interfere with that determination. The problem presented to the Metropolitan Sewerage Commission was one of engineering, and their determination is in the last analysis a determination of fact, and where there has been a substantial compliance with the legislative command no question of law is presented.
In the territory referred to in sub. (a) of the fourth finding, it may well be that trenches to a considerable depth will have to be dug in order to throw the sewage from the strip of land there referred to into the system which will be served by the sewage disposal system of the city of Milwaukee. If that is not done, however, sewage will find its way into Lake Michigan and the whole object and purpose of the entire scheme might thereby-be defeated, viz. to secure for the city of Milwaukee and its environs as pure a water supply as possible.
Ch. 554 is assailed as unconstitutional on the ground that it violates sub. 7, sec. 31j art. IV, Const., which provides:
“The legislature is prohibited from enacting any special or private laws in the following cases: . . , 7tn. For granting corporate powers, or privileges, except to cities.”
The law is said to be special because by its terms it can [51]*51only apply to the county of Milwaukee for the reason that the county of Milwaukee is the only county within the state of Wisconsin in which there is situated a city of the first class and because of the other qualifications enumerated in sub. (1), sec. 1, ch. 554. This raises a question which has often been considered by this court, and that is whether or not a law which in fact can apply but to one county is a general or a special law. Every proposition urged for our consideration here was urged and fully answered in Bingham v. Milwaukee Co. 127 Wis. 344, 106 N. W. 1071. See, also, State ex rel. Busacker v. Groth, 132 Wis. 283, 112 N. W. 431.
While the basis of classification in ch. 554 is not that of population, a moment’s examination discloses the fact that it is not a closed class; that as soon as there is any other county in which there is a city of the first class which has made provision for the sewage disposal plant as provided, the class will open and ch. 554 will by its terms become applicable to any county containing a city of the first class which has complied with the terms of sub. (1), sec. 1, ch. 554. Whatever may be said for or against a classification which permits the enactment of legislation which in fact at the time of its adoption applies and in all human probability for some considerable time in the future can never apply to any but a single county within the state, it is a matter which is no longer an open question in this state. The act being by its terms general, it is not within the provisions of sub. 7, sec. 31, art. IV, Const. Whether or not under the principle laid down in State ex rel. Baltzell v. Stewart, 74 Wis. 620, 43 N. W. 947, and Muskego v. Drainage Comm’rs, 78 Wis. 40, 47 N. W. 11, the legislature may, for the purpose of promoting the public health, enact a constitutional law creating a district embracing-within its limits territory lying in more than one county, having some corporate powers, is a question not before us in this case.
[52]*52It is next urged that ch. 554 contravenes sec. 22, art. IV, Const.:
“The legislature may confer upon the boards of supervisors of the several counties of the state such powers of a local, legislative and administrative character as they shall from time to time prescribe.”
And sec. 23, art. IV:
“The legislature shall establish but one system of town and county government, which shall be as nearly uniform as practicable.”
In support of this proposition are cited State ex rel. Keenan v. Milwaukee Co. 25 Wis. 339; State ex rel. La Valle v. Sauk Co. 62 Wis. 376, 22 N. W. 572; McRae v. Hogan, 39 Wis. 529; Wagner v. Milwaukee Co. 112 Wis. 601, 88 N. W. 577.
In State ex rel. Keenan v. Milwaukee Co., ch. 372, P. & L. Laws 1869, was under consideration. By that chapter three commissioners were appointed to superintend the erection of a courthouse in the county of Milwaukee, a matter which was committed by general law to the county board of Milwaukee county. It was held that ch. 372 was void because in conflict with that provision of the constitution which requires but one system of town and county government shall be established, which shall be as nearly uniform as practicable. We do' not see that that case has any applicability whatever to the questions presented here.
Our attention is called to no provision of the law conferring upon county boards the power to erect and maintain a sewerage system, and we find none. Upon what basis, then, can it be argued that ch. 554 violates sec. 23, art. IV, Const., which requires uniformity of town and county government ?
In State ex rel. La Valle v. Sauk Co., supra, ch.315,Laws 1881, was held unconstitutional, it being an act relating to county aid in the construction of bridges, because it provided [53]*53that the act should not apply to the county of Grant, a clear violation of the constitutional provision.
In McRae v. Hogan, supra, it was held that ch. 458, P. & L. Laws 1869, was invalid because it attempted to take from the possession and control of the town officers of Chippewa county a portion of the moneys raised in the towns for highway purposes and intrusted its expenditure to the county board. The law applied to no county in the state except Chippewa, and it was held that it violated the provisions of sec. 23.
In Wagner v. Milwaukee Co., supra, ch. 310, Laws 1899, which authorized the board of supervisors of any county to construct a viaduct, etc., provided such viaduct shall not be less than 1,000 feet long, 60 feet wide and 18 feet high and cost not less than $80,000, and the amount of bonds issued therefor shall not exceed one fifth of one per cent, of the taxable property of the county, it- was held that this act attempted to give to the county of Milwaukee powers of local government not enjoyed by any other county of the state and hence was repugnant to sec. 23.
Ch. 554 attempts to confer no powers upon the county board of Milwaukee county. The Metropolitan sewerage district is at least a gwajj-municipal corporation organized for the purpose of promoting the public health, the officers of which are chosen in the manner designated by the act. All the powers to be exercised in the organization, construction, and maintenance of the district are to be exercised by the Metropolitan Sewerage Commission. The county officers of the county of Milwaukee and the town, city, and village officers of the various towns, cities, and villages in the county of Milwaukee are not given additional powers by the terms of the act. By the terms of the act, when certain things are done by the Metropolitan Sewerage Commission the various county, city, town, and village officers are required to do certain things, as to the doing of which they have no discretion, as for instance the matter of the issuing [54]*54of the bonds, certification of taxes, the collection and disbursement of funds are provided for, not in the discretion of the governing bodies of the various municipalities but by the legislature itself by the express terms of the law. The act, therefore, is not in contravention of the principles laid down in State ex rel. Carey v. Ballard, 158 Wis. 251, 148 N. W. 1090. In that case, sub. 3, sec. 1317m — 4, Stats. 1913, was under consideration. By the terms of that act a town board was required to levy a highway tax whenever “any group of freeholders in the county desiring the improvement of a portion of the system of prospective state highways lying within that town” should present a petition for such improvement and comply with certain conditions therein specified. This was held unconstitutional and void because it attempted to delegate legislative power to levy a tax to a group of freeholders in their individual capacity. Manifestly, under the terms of ch. 554 no such power is conferred upon any body of persons individual or corporate. By the provisions of sub. 6, sec. 1, ch. 554, the Metropolitan Sewerage Commission is required to project, plan, construct, and maintain first-class main sewers. The Commission itself does not determine whether or not this shall be done. The legislature has determined it for them and has committed the execution of the legislative plan to the Metropolitan Sewerage Commission. Whenever the Commission requires funds for carrying out the legislative plan, the method by which said funds are provided is specified in sub. 7, to which reference is made. The amount which the Metropolitan Sewerage Commission is authorized to certify is that amount which is necessary to carry out the legislative scheme. The taxing power of the state is exerted through the Metropolitan Sewerage Commission and the various governing bodies and officers of the various municipalities by the legislature, and the funds raised in the manner specified can be disbursed for the purposes specified in the act and no other. The powers exercised by the Metropolitan Sewerage Commis[55]*55sion under the provisions of ch. 554 are in a general way analogous to those exercised by the officers of a school district or by the commissioners of the various drainage districts organized under the general law, being in most respects much narrower and more closely limited than are the powers either of the school boards or the drainage commissioners.
The act does not offend the constitution in the particulars referred to, as appears from prior decisions of this .court. Sutter v. Milwaukee Board of Fire Underwriters, 161 Wis. 615, 155 N. W. 127; Borgnis v. Falk Co. 147 Wis. 327, 133 N. W. 209; State v. Lange C. Co. 164 Wis. 228, 157 N. W. 777, 160 N. W. 57; Rattlesnake D. Dist. v. Koshkonong Mud Creek D. Dist. 150 Wis. 223, 136 N. W. 631; Rinder v. Madison, 163 Wis. 525, 158 N. W. 302; Stone v. Little Yellow D. Dist. 118 Wis. 388, 95 N. W. 405. See, also, Houck v. Little River D. Dist. 239 U. S. 254, 36 Sup. Ct. 58; Wilson v. Board of Trustees, etc. 133 Ill. 443, 27 N. E. 203; People ex rel. Longenecker v. Nelson, 133 Ill. 565, 27 N. E. 217.
It is also urged that ch. 554 violates sec. 1 of art. VIII of the constitution, which provides that taxation shall be uniform and taxes levied upon such property as the legislature shall prescribe. •-
Donnelly v. Decker, 58 Wis. 461, 17 N. W. 389, is cited, and it is argued in support of the proposition that, the tax provided for by ch. 554 being a general tax, the entire county and every subdivision therein is justly liable to bear its proportion of such tax; that inasmuch as by the terms of ch. 554 the tax is to be levied only upon the property in the Metropolitan sewerage district, the rule of uniformity is violated. Donnelly v. Decker holds that an improvement which will conduce to the public health or welfare may be made at the expense of the property which will be directly benefited thereby. That case had to do with the draining of marsh, swamp, and overflowed lands and [56]*56controverts rather than supports plaintiffs’ position in this case. The legislature in this case has merely created an overlying taxing district and has directed that the funds necessary for the construction of the designated improvements shall be raised by taxation of the property directly benefited thereby. This it may constitutionally do. State ex rel. Baraboo v. Sauk Co. 70 Wis. 485, 36 N. W. 396; Rude v. St. Marie, 121 Wis. 634, 99 N. W. 460; Milwaukee Co. v. Halsey, 149 Wis. 82, 136 N. W. 139; Dickson v. Racine, 61 Wis. 545, 21 N. W. 620; Bryant v. Robbins, 70 Wis. 258, 35 N. W. 545.
In this case the legislature in a general way, by the provisions oí ch. 554, established the boundaries of the Metropolitan sewerage district, which boundaries were made definite and certain by the act of the Metropolitan Sewerage Commission, in the exercise of a power conferred upon them by the terms of the act. The legislature directed that the Metropolitan Sewerage Commission do certain things with reference to the construction and maintenance of the Metropolitan sewerage system and that the funds with which such system should be constructed and maintained should be provided in the way therein designated. The act therefore established the boundaries of the taxing district, directed what moneys should be raised by taxation, and left to the Commission and the various taxing officers merely the ministerial duty of determining the necessary amounts and providing therefor on the tax roll. In so doing it is clear there was not an unconstitutional delegation of either legislative or taxing power. Bryant v. Robbins, 70 Wis. 258, 35 N. W. 545; Dickson v. Racine, 61 Wis. 545, 21 N. W. 620.
By the enactment of ch. 554 the state, through the legislature, has exercised for the promotion of the public health and general welfare the broadest as well as the most indefinite of all its powers, the police power. With the wisdom of the act or the matters of public policy involved or the choice of methods by which the legislative purpose is to be effected, [57]*57the court has nothing to do unless the act clearly contravenes some constitutional provision.
We have carefully examined the several grounds urged and have given the case the consideration which its importance warrants and have stated rather briefly our conclusion, and have not discussed as fully some questions involved directly and collaterally as we should wish to do were there more time. It appears that large public interests await the determination of the issues in this case. We have concluded, therefore, to announce the decision as promptly as possible. The questions involved.have been discussed in the cases referred to, so that under the circumstances further elaboration is not required.
The Metropolitan Sezuerage Commission proceeded in the manner specified in the act to determine the boundaries of the district, and its determination in that respect cannot be disturbed. Ch. 554 is a constitutional exercise of legislative power and the act well within the field of legislative discretion. The findings of the trial court both as to matters of fact and conclusions of law are amply sustained, and the judgment must be affirmed.
By the Court. — It is so ordered.