10 per cent allowance for amortization and repairs.

Acknowledgment.-The fundamental data on which the studies for Wyandotte rest were obtained from records which the mayor, Mr. C. H. Marr, very kindly furnished.

TRENTON, MICH.

The village of Trenton, Mich., is located on the Detroit River, and is the farthermost downstream community of importance on the Michigan side. It has no manufacturing interests, and appears to depend largely for its existence on the trade of the agricultural section which lies to the west and southwest. It is not sewered in any complete sense, there being in fact only one sewer, which is owned by the municipality. This is a combined sewer which serves only a small part of the city and discharges at the southern end of Fifth Street into a bog which outlets through a small creek into the Detroit River. Owing to the fact that there are no communities below this on either side which would be affected by the small amount of sewage now being discharged, the plan presented herewith is designed to cover the needs of the future rather than the present.

On two distinct occasions sewerage propositions, based on the combined system, have been before the people, and both times they have been voted down on the grounds that the expense was too great. The engineer's estimate for the last and cheapest of these projects was about $35,000. There is little need at the present time for storm-water sewers, nor is there likely to be any such need in the near future. It is probable, however, that the citizens would welcome a less expensive sanitary system, and therefore studies for this city have been confined to the layout of a separate sanitary system, with a treatment plant. The city is built on relatively high ground, so that it has been possible to plan a layout which avoids the necessity for pumping.

The population has been about 1,200 for 30 or 40 years and will likely continue about the same in the future, unless some unforeseen change takes place.

On account of the distance from Detroit, about 11 miles, it does not seem likely that it will be affected by overflow from there for a long time.

The water-pumping records, after making allowance for use by railroads, indicate a daily per capita consumption of 133 gallons. As this is obviously too high for this community, there must be a large waste by leakage, lawn sprinkling, etc. For the purpose of sewer design it has been assumed that 80 gallons per day will be contributed by each person and that there will be an additional flow of 500 gallons per acre from infiltration of ground water.

The sewer layout is shown on plate 29, with a treatment plant discharging into the small creek south of the city, and the estimated cost of the project is presented herewith, as follows:

The operation of the treatment plant would only require a few hours' attention daily. The cost for labor and materials should not exceed $500 per year.

As Trenton has practically no sewerage system at the present time the item for sewers on the estimate given above should be considered as a collection system rather than an intercepting system and therefore not a cost incident to the installation of a treatment process. On this basis the cost incidental to treatment is given in Table No. 85.

TABLE NO. 85.-First cost and annual charges for Trenton, Mich.-1,200 population.

AMHERSTBERG, ONTARIO.

The city of Amherstberg, Ontario, is the farthermost downstream municipality on the Detroit River. It possesses no manufacturing establishments of consequence and has had an erratic trend as to growth in past years. The population was 1,936 in 1871, 2,672 in 1881, 2,279 in 1891, 2,222 in 1901, and 2,560 in 1911. There is no apparent reason to expect that it will grow rapidly in the future, and it has been assumed that interceptor provision for 4,000 people and treatment-plant provision for 3,000 people will be ample.

No regular records are kept of the water pumped, but from a statement of the pumping-station engineer as to the number of times the water tank is filled during a day, it appears that the daily per capita consumption is about 165 to 170 U. S. gallons. As this information is of meager nature, and as Amherst berg is a very old city, so that the water mains are probably in a very leaky condition, the interceptor has been designed on an assumed water consumption of 125 U. S. gallons per capita daily, with a sewage contribution therefrom of 100 U. S. gallons per capita per day, to which has been added a ground-water allowance of 1,000 U. S. gallons per acre per day, and a further allowance of 100 U. S. gallons per capita per day to cover drainage which enters the existing sewers from the rural districts back of the city.

The estimated cost of the project is presented herewith, as follows, and includes the cost of a separate sludge-digestion tank, not shown on any of the plates:

TABLE NO. 86.-Cost for Amherstberg, Ontario 8,000 population.

Item.

1,240 feet of 10-inch sewer.....

580 feet of 12-inch sewer.

700 feet of outfall sewer..

Diversion chambers and tide gates...

Pumping station:

2,000

2,300

4,300

$2.25

6,750 250

17,05%

• Per capita.

Acknowledgment.-Mr. H. L. Bloomshield, village engineer, rendered material assistance in furnishing maps and making available other information of value for the Trenton study.

The existing sewerage system has two outlets, one in Richmond Street and the other in Park Street. There is a suitable site for a treatment plant just south of Park Street, which permits the use of a short interceptor line. The interceptor shown on plate 30 and in profile on plate 31, designed to carry the sewage to a pumping station at this site, follows Dalhousie