lets. The tank will have a total capacity of about 22,000 gallons, equal to nearly one day's flow of sewage when serving a population of 250 and assuming a per capita rate of sewage contribution of 100 gallons per day. The sludge is to be disposed of on a sludge drying bed 27 feet square by 2 feet deep to be located some 300 feet from the settling tank. The sludge pipe is to be 6 inches in diameter and will have an average slope of about 5 per cent. The bed is not to be provided with underdrains and it does not appear necessary to drain the bed owing to the porous nature of the soil which is claimed to be of a gravelly loam.

The subsurface irrigation system is to consist of a main distributing trough and 42 lines of lateral distributors 200 feet long each, giving a total of nearly 9,000 feet of tiling or about 36 feet of tile per person served on the basis of design used. The distribution system will cover an area of nearly one acre and will, therefore, provide for a rate of operation of approximately 25,000 gallons per acre per day.

The main distributing trough is to be provided with baffles located below each of two sets of lateral distributors so that it will be necessary to fill two upper lines of distributors before effluent will flow over the baffle into the next set of two lines of distributors. These baffles are removable so that it will be possible to shut off the flow to the various lines of distributors by removing the different baffles.

The lateral distributors are to consist of 3-inch agricultural tile, laid with slopes of 4 inches in 100 feet at a depth of about 18 inches below the surface of the ground. The tile are to be laid with open joints and the joints are to be covered with tar paper. According to the data submitted with the plan the soil is of a loose gravelly nature and should be well adapted to the disposal of sewage by means of subsurface irrigation. There appears also to be adequate area available for the extension of the system if necessary in the future. The field, moreover, appears from the topography to be so located that there should be little or no opportunity for the pollution of the wells which are to be situated about 900 feet from the disposal plant and beyond a rise in the ground.

It is noted from the specifications for plumbing that lavatories with no plugs at the outlets are specified. This would in all probability give rise to considerable waste of water and does not appear to be necessary.

From our careful examination of the plans I am of the opinion that the proposed water supply and sewage disposal system if properly constructed in accordance with the plans and if operated with care and efficiency should satisfactorily meet the requirements for which they were designed, and I would, therefore, recommend that the plans approved.

Respectfully submitted,

ALBANY, N. Y., June 20, 1917

THEODORE HORTON,

Chief Engineer

The plans were approved July 11, 1917.

ROCKVILLE CENTER (Clinton School and South Side H. S.) HERMANN M. BIGGS, M.D., State Commissioner of Health:

I beg to submit the following report on our examination of plans for the disposal of sewage from the Clinton School and the South Side High School at Rockville Center, Nassau county, submitted to this Department for approval on July 17, 1917.

The records of the Department show that the plans for the disposal of sewage by means of a cesspool for the Clinton School in the village of Rockville Center were submitted to this Department for approval through the State Education Department in August, 1916. The Education Department was advised that it appeared from our examination of the plans that the

sewage disposal plant provided for by the plans would be inadequate to care for a large school, and it was pointed out that better results and greater security of permanent satisfactory operation would be obtained by constructing a disposal plant consisting of a settling tank and subsurface irrigation system.

The plans for the disposal of sewage for the Clinton School and South Side High School at Rockville Center in cesspools were first submitted for approval on July 6 of this year. No data were submitted with the plans as to the nature of the soil and the population to be served by the school, but it was apparent from the number of toilet fixtures shown by the plans that the attendance at the schools would be large and it did not appear that cesspools would satisfactorily care for the sewage from schools as large as those indicated by the plans. They were therefore returned with the recommendation that some other means of disposal, such as subsurface irrigation, be provided for.

We were subsequently advised by the principal of the Rockville Center public schools on July 12 that the Clinton school is located in the center of the village near the middle of a plot of ground 300 feet long by 200 feet wide, and that the area available for the disposal system is only about 100 feet. It was stated that the locations of the toilet rooms, which will be used by about 600 pupils, are so low that the sewer where it emerges from the building will be about 72 feet below the surface of the ground, making it impracticable to install a subsurface irrigation system.

With respect to the South Side High School it was stated that this school was located on the plot of ground about 200 feet long by 175 feet wide, and that about 200 pupils are to be provided for at this school. The sewer at the building will also be about 7 feet below the surface of the ground. It was stated that there are no wells in the village and that the soil is sandy. It appears that the sewage from one of the school buildings in the village is satisfactorily disposed of by means of cesspools and that there are a number of other large schools in that section of Long Island which use cesspools for the disposal of sewage.

After a careful consideration of the above data the principal of the school was advised that under the circumstances it would seem advisable to attempt to dispose of the sewage from the schools by means of cesspools rather than by means of subsurface irrigation systems, as previously recommended. It was recommended that 4 cesspools each 10 feet in diameter and 10 feet deep below the flow line be provided for the Clinton school and 2 cesspools for the South Side High school, and that the walls of the cesspools should be constructed of hollow tile or hollow brick filled with sand, so that in case of clogging the sand in the tile may be withdrawn and new sand placed in the hollow tile or brick.

The plans now submitted provide for 3 cesspools about 10 feet deep and 10 feet in diameter for the Clinton School to be operated in series and 2 similar cesspools for the South Side High School also to be operated in series. The cesspools according to the plans are to be constructed of ordinary red brick, every sixth course of which is to be laid in cement mortar. It appears, therefore, that the recommendations of our letter of July 15 have not been fully complied with in that only 3 cesspools are to be provided for the Clinton School in the place of 4 as recommended, and that the cesspools are to be constructed of ordinary brick in place of hollow brick or hollow tile.

It is highly important that special care should be taken in the construction of the cesspools at these schools owing to the large population to be served and the considerable quantity of sewage to be cared for in order to give reasonable assurance that the cesspools will not prove unsuccessful and that overflowing of them will not result thereby, necessitating the construction of additional works for the treatment of the sewage. Not less than 4 cesspools should be provided for at the Clinton School and all except the first cesspools into which the sewage from the toilets is discharged should be so arranged as to permit of throwing either one of the cesspools out of use

in case of clogging. The manholes of the cesspools should also be carried to the surface of the ground and provided with manhole covers in order to permit of regularly inspecting the cesspools and in order to give an opportunity to construct additional cesspools or additional works for the treatment of the sewage should the cesspools first constructed prove to be inadequate. In view of the above, I would recommend that the plans be approved on the following conditions:

1. That not less than 4 cesspools be provided for at the Clinton School and that these cesspools be so arranged as to permit of throwing one or more of the cesspools out of use for resting if necessary.

2. That the cesspools be constructed with hollow brick or hollow tile. 3. That whenever necessary or required additional cesspools or additional works for the treatment of the sewage of the school shall be provided.

ALBANY, N. Y., July 23, 1917

Respectfully submitted,

THEODORE HORTON,

Chief Engineer

The plans were approved July 23, 1917.

ROCKVILLE CENTER (St. Agnes School)

HERMANN M. BIGGS, M.D., State Commissioner of Health:

I beg to submit the following report on our examination of the plans for sewage disposal for the St. Agnes Parochial School at Rockville Center, Long Island, N. Y., submitted to this Department for approval on October 17, 1917. The proposed disposal systems, which will consist of 2 separate series of 2 cesspools each, are to treat the sewage from 4 flush closets and 8 urinals in the boys' toilet and the other system will treat the sewage from 8 flush closets in the girls' toilet. The soil in the vicinity of the school house is sandy and it is stated that from the surface of the ground to the ground water level there is at least 20 feet of fine sand. There are no wells within 1⁄2 mile of the proposed cesspools and the nearest residence is about 80 feet distant.

The sewage from each of the toilets is to be conveyed to the first leaching cesspool through about 35 feet of 6-inch vitrified pipe laid on a slope of about 5.7 per cent. This cesspool which is to be circular in plan, is to be 12 feet in diameter and will have a depth of about 11 feet below the intake pipe, giving a capacity of about 8,500 gallons. The wall of the cesspool is to be of hollow tile so that the sewage may leach out into the surrounding sandy soil. The top of the cesspool is a brick and cement dome having a manhole opening. It appears from an examination of the plans that there is to be no bottom constructed for the cesspool, so that the sewage may also leach through the soil at the bottom.

There is an overflow pipe from this first cesspool through which the excess sewage effluent is to be conveyed to the second leaching cesspool, this pipe consisting of about 25 feet of 6-inch vitrified tile. This second cesspool is to be constructed in the same manner as the first cesspool described above.

We have found that in disposing of the sewage from institutions of this size, and where the nature of the soil permits, as it does in the vicinity of the school in question, that a more suitable method of disposing of the sewage is by the use of a settling tank and subsurface irrigation system. However, since the sewer pipes as they leave the toilet rooms are laid at a depth of 5 feet below the ground surface, and enter the cesspools at a depth of 7 feet below the ground surface, it would be difficult to intall a system of subsurface irrigation for disposing of the sewage since it would be impossible to deliver the sewage in lateral or distributing tiles laid near the surface of the ground without resorting to pumping.

In view of the above conditions I therefore recommend that the plans be approved.

ALBANY, N. Y., October 20, 1917

Respectfully submitted,

THEODORE HORTON,
Chief Engineer

The plans were approved October 22, 1917.

RYE (A. C. Gwynne)

Plans for the disposal of the sewage from the property of Mr. A. C. Gwynne at Rye, Westchester county, N. Y., were submitted to this Department for approval on December 28, 1916. These plans provide for the construction of a sewage disposal plant consisting of a settling tank, a dosing chamber, and a covered sand filter. The effluent from the sand filters is to be discharged into Long Island Sound.

The plans were approved and a permit issued for the discharge of the effluent into Long Island Sound on January 12, 1917.

SAUGERTIES (Thomas Cochran farm)

HERMANN M. BIGGS, M.D., State Commissioner of Health:

I beg to submit the following report on the examination of the plans for improvements in the method of sewage disposal at the Thomas Cochran or Gray Mouse farm in the town of Saugerties, near Kingston, Ulster county, N. Y., submitted to this Department for approval by the designing engineers on August 6, 1917. Additional information regarding the plans was submitted to the Department on August 30, and October 20, 1917.

The Thomas Cochran farm is located on the west bank of the IIudson river, 8 miles north of Kingston, and consists of a narrow strip of land about 1,000 feet wide, extending from the bank of the river for a little over a mile and a half in a westerly direction. The soil is a clay overlying shale and limestone rock which outcrops at several points.

During the summer months, the farm is used by the New York City Association for the Improvement of the Condition of the Poor as a fresh air home for 40 girls; and from June to October the total population is approximately 50 persons. During the winter, only the caretaker and his family live on the property.

The buildings consist of a dormitory, farm house, laundry and several barns and sheds. The dormitory is occupied by 21 children and their attendants, and is provided with running water and plumbing fixtures. The sewage from this building is at present treated by a sewage disposal plant consisting of a sedimentation tank, dosing chamber and sand filters. The sedimentation tank is a covered masonry structure of 1,000 gallons capacity and provides an average detention period for the sewage of about 12 hours. A dosing chamber of 300 gallons capacity adjoins this tank, into which the effluent from the tank flows and from which it is discharged by a 3-inch siphon onto the sand beds. The arrangement of the tank outlet is such that each discharge of the dosing chamber draws the tank down several inches giving a dose of about 500 gallons, a quantity equivalent to a depth of approximately 14 inches on one sand bed. A diverting gate is provided by which the attendant can turn the dose onto either of the two sand beds at will. Each of these sand beds has an area of 0.015 of an acre making a rate of filtration with both beds in use about 70,000 gallons per acre per day. The depth of the beds is

3 feet, and by the effective size of the sand 0.35 mm. The sewage is distributed on the beds by perforated iron troughs; and the effluent collected by tile underdrains, and discharged into a branch of the farm ditch about 300 feet southeast of the dormitory. The engineers' report states that the plant is in good condition and operating satisfactorily.

The farm house has a population during the summer months of 22 persons and like the dormitory, is provided with running water and plumbing fixtures. The sewage from this building flows to a closed concrete tank of 800 gallons capacity, giving an average detention period of about 61⁄2 hours. The effluent from the tank passes through a subsurface charcoal filter, and from this filter is discharged into the farm ditch. No details of the charcoal filter have been furnished and the engineers' report states that the use of this filter is to be abandoned.

The laundry is at present not supplied with running water. All the water used for laundry purposes being carried by hand from a nearby well. The wastes from the building are discharged on the top of the ground.

According to the plans and the engineers' report it is proposed to make the following improvements in the method of sewage disposal at the farm.

A 6-inch vitrified pipe sewer is to be laid from the laundry to the sedimentation tank serving the dormitory. This line will be 550 feet long, and is to be laid on a grade of 0.5 per cent. There is one bend in this line, and a manhole is provided at this point. If running water is installed at the laundry as intended, the additional quantity of sewage that will be conducted to the dormitory sedimentation tank by this line will probably reduce the detention period of the tank to about 8 hours, and increase the rate of filtration in the sand beds to about 85,000 gallons per acre per day. There seems to be no reason why, with proper attention, the plant should not give satisfactory results when operated at these rates.

The 6-inch outfall sewer from the sand beds at the plant serving the dormi tory is to be extended 300 feet and the effluent from the plant discharged into the farm ditch at a point about 700 feet east of the dormitory. The grade of the extension will be 1.04 per cent.

The outfall sewer from the sedimentation tank serving the farm house is to be extended about 600 feet and effluent discharging into the farm ditch at the same point at which the effluent from the plant serving the dormitory will be discharged. This line will be of 6-inch vitrified tile laid on grades varying from 1.2 to 7.5 per cent.

There are several bends in each of these extensions, and no manholes are provided at these points, but since the line will carry only the plant effluent no trouble should be experienced from stoppages. The stream in the farm ditch into which these outfalls will discharge is small, but is said always to have some flow.

A chlorinating apparatus is to be installed in the shed about 150 feet below the sedimentation tank serving the farm house, and the effluent from the tank is to be treated with chlorine at the rate of 7.2 parts per million, applied at the manhole adjacent to the shed. This installation is intended for temporary use only. If it is decided to occupy the farm house permanently the owner intends to build a sewage disposal plant consisting of sedimentation tanks and sand filters of suitable size to care for the flow from the building. No details of the chlorinating apparatus or the manner in which chlorine will be applied to the tank effluent have been submitted. Some arrangement should be made at the point of application to assure a thorough mixture of the chlorine with the effluent.

In view of the results of our examination of these plans and after careful consideration of the essential features of the design, I beg to recommend that the plans be approved and a permit issued for the discharge of the effluent from the sewage disposal plants into a stream on the Thomas Cochran property tributary to the Hudson river with the following conditions:

1. That whenever required by the State Commissioner of Health a plant for the more complete treatment of the sewage from the farm house be constructed and put in operation.