The revised plans were approved under the following conditions:

1. That a manhole be placed at a point where the main sewer divides and that a sluice gate be installed instead of the gate valves as shown on the plans. This is for the purpose of facilitating the cleaning out and repairing of either one of the branches of the main sewer.

2. It appeared from the plans that the effluent will discharge on the surface of the ground. The board, therefore, required that provision be made for extending a pipe from the tank to the river through which all of the effluent must pass.

JACKSON. SEWERAGE SYSTEM.

The revised plans for a public sewer system for the village of Jackson were approved on April 18, 1914. Provision is made in these plans for the construction and operation of two septic tanks, one located east of the village and the other near the western limits. This virtually constitutes two separate systems, but on account of the topography of the country, it was deemed advisable to install the system in this manner.

MENOMONIE. SEWERAGE SYSTEM.

The combined storm and sanitary sewerage system for the second sewer district of the city of Menomonie were approved on March 31, 1914. The plans were approved as a storm water system with the privilege of using this system for the disposal of household waste until a sanitary sewer is installed or until such time as it may be necessary to purify the sewage in a more complete manner than can be done where a combined system is used.

These plans were approved under these conditions for the reason that it appeared from a personal investigation that the greatest need of this district, at the present time, is for storm water sewers. Not more than fifteen homes will connect with the sewerage system for several years.

OCONOMOWOC. SEWERAGE SYSTEM.

The plans for a sewage purification plant were approved on February 24, 1913. The plans, as approved, provide that the city sewage shall be collected in an old pump well which is now used as a sedimentation basin. From this well the effluent flows through a large reservoir excavated in a gravel formation found in this locality. The effluent from the reservoir is discharged

through the gravel bed and any surplus passes over the small weir at the outlet end of the reservoir. About twice each month the deposits are pumped into the old septic tank used for the purpose of collecting this material. Any liquids which are pumped into the tank with the solid material are discharged on the old filter beds. The effluent from the filter beds are disposed of in the river.

PRAIRIE DU CHIEN. SEWERAGE SYSTEM.

The plans for this system were approved on June 2, 1913 under the following conditions:

That the outlet be extended at least 1100 feet so as to reach the channel of the Mississippi river in order to prevent the accumulation of decomposed sewage material in the stagnant arm of the slough.

Permission was granted the municipality to make this extension at any time within one year so that the work could be done at a time when the water in the river is at a low stage.

PARK FALLS. SEWERAGE SYSTEM.

The plans for the proposed sewerage system for Park Falls were approved on July 23, 1913. A purification tank is provided through which all sewage must pass.

The plans were approved as presented.

SHEBOYGAN FALLS. SEWERAGE SYSTEM.

The plans and specifications for a sewerage system for the village of Sheboygan Falls were approved on September 21, 1913. The system is constructed to take care of approximately 170,000 gallons of sewage per day all of which is treated in a septic tank and the effluent is discharged into the Sheboygan river. The sludge is disposed of by being distributed over an adjacent tract of land which is preserved for that purpose.

WEST BEND. SEWERAGE SYSTEM.

The plans for the extension of the sewerage system for West Bend were approved on May 28, 1913. Provision is made for taking care of approximately 10,000 gallons of sewage per day. Purification tanks are provided for.

WAUPUN. SEWERAGE SYSTEM.

The plans for this system were approved on July 29, 1913. The purification system provided for at Waupun is the Imhoff tank method. The system is designed for the installation of a filtration system if necessary.

The plans and specifications for the proposed sewerage system for District No. 1 of the city of Wabeno were approved on September 30, 1913.

The plans were approved with the following changes:

1. The septic tank shall be so located and constructed that if necessary to use filtration beds this can be done without materially changing the present system.

WEST MILWAUKEE. SEWERAGE SYSTEM.

The plans provide for an extension of the present sewerage system and were approved on May 7, 1914.

The plans were approved as presented.

MILWAUKEE HOUSE OF CORRECTION. SEWERAGE SYSTEM.

The plans for this system were approved on May 13, 1914. Provision is made in these plans for collecting all sewage from the institution in a septic tank especially designed for that purpose.

The plans were approved as presented.

A SANITARY SURVEY OF LAKE MICHIGAN ALONG THE WISCONSIN SHORE.

By E. J. TULLY, Chemist, State Laboratory of Hygiene, Laboratory of the State Board of Health.

(Reprint of the Cleveland Medical Journal, Vol. XI, page 809)

There is probably no better municipal supply in this country than that furnished by Lake Michigan, if drawn at such a location that it is free from sewage pollution. The Lake was originally a body of pure water, but with the development of industrial and commercial life along its shores the time came when the increased industrial and household waste had to be gotten out of the way and it was natural enough that the large body of water near at hand, apparently capable of receiving and rendering innocuous any amount of sewage, should serve as the disposal ground.

Accompanying the growth of the cities came the demand for and the necessity of a sufficient supply of pure water. The ground and surface waters could no longer be depended on to ensure an adequate and suitable supply of water, consequently the people turned to the Lake for water, and now for a number of years they have been discharging sewage into Lake Michigan through one pipe and pumping out a water supply through another. The Lake near the shore, however, is not only polluted by the discharge of city sewage, but by other sources as well, such as the discharge of harbor water, the discharges from creeks, the shore wash and stirring up of the bottom of the Lake by winds and currents, dumping of dredging material and accidental pollution by steam boats, sailing vessels, and other shipping.

The municipal authorities, awake to the danger of using the polluted shore water as a source of supply, deemed it possible

to secure a reasonably safe water by extending the intake to one-half mile or so from shore and locating the sewage discharge pipe to the south of the water intake pipe, hoping in this manner to divert the sewage from the source of drinking water; but as the outlet of the Lake is comparatively small, relatively to the quantity of water it contains, there is no direct flow and the movements of the water are almost entirely dependent on local winds, which greatly overbalance the general movements of translation and drive the waters one way or the other according to their direction, velocity and duration. The atmospheric temperature also influences these movements, and near the mouth of large streams these, too, have this effect. The results of our survey conclusively show that no definite currents exist which can be relied upon to protect a water works intake from adjacent sewage pollution and so-called drift, caused by unbalanced movements of the wind; hence it is assuredly unsafe to assume that the discharge of sewage into the Lake in a particular direction furnishes a means of protection for a water supply. That such reasoning is erroneous is amply attested to by the typhoid fever and other intestinal troubles that have appeared in certain cities along the lake front with more or less frequency.

Our purpose in making the survey of Lake Michigan along the Wisconsin shore was to find whether the water is safe to drink without filtration, and also to determine the extent of pollution of the water along the shore; also to ascertain the general quality of the water over a considerable period of time and under a variety of conditions, desiring in this manner to determine the extent to which the Lake could be relied on to furnish a safe supply.

The study of the water was first undertaken in the summer of 1909 and has been going on at the State Hygienic Laboratory under the general direction of Doctor M. P. Ravenel, Director of the Laboratory, for the last three summers. The work has been done, in a general way, in conjunction with the Lake Michigan Water Commission and the methods of procedure have been in general, the same as those used by the states of Michigan, Indiana and Illinois.

Surveys have been made at Kenosha, Racine, Milwaukee, Sheboygan and Manitowoc, and it is our desire and expectation to complete the work by making studies at some of the larger cities north of Manitowoc next year. At each city where exam