[HISTORY: Adopted January, 1955. Amendments noted where applicable.]
Sewers and sewage disposal — See Ch. 189.
Make application for a permit, said application to be accompanied by a description of the proposed sewage-disposal system, including soil seepage data and a lot plan showing the location of the system in relation to buildings, well and lot boundaries. Fee, three dollars ($3.). (Forms obtainable at Town Hall or from Sanitary Inspector.)
Notify the Sanitary Inspector when the sewage system is completed and ready for covering, in order that he may make final inspection.
Minimum diameter, four (4) inches; grade, one-fourth (1/4) inch per foot. For five-inch or six-inch pipe, at least one-eighth (1/8) inch per foot.
Extra-heavy cast-iron pipe with leaded joints from house to septic tank.
Extra-heavy cast-iron pipe with leaded joints for any portion of the pipe which is within seventy-five (75) feet of a well, but in no case shall the sewer pipe come within twenty-five (25) feet of a well.
Cast-iron pipe with leaded joints if within twenty-five (25) feet of a cellar or groundwater drain which discharges into a stream or culvert or on the surface.
No septic tank, cesspool, tile field, seepage bed or privy vault shall, without approval of the Sanitary Inspector, be constructed within:
Seventy-five (75) feet of a well or spring.
Fifty (50) feet of streams or ground- or surface water drains tributary to a water supply system.
Fifteen (15) feet of a dwelling on the lot.
Fifty (50) feet of a dwelling on an adjoining lot.
Ten (10) feet of property lines.
Twenty-five (25) feet of a stream, pond or lake.
Twenty-five (25) feet of a storm, cellar or subsoil drain which discharges into a steam, culvert or on the surface of soil, unless such drain is constructed of cast-iron pipe with leaded joints.
Location: At least ten (10) feet from the nearest cellar wall. See also other location restrictions above. (§ A237-4.)
Size: Minimum five hundred (500) gallons liquid capacity, which shall serve not more than five (5) persons; for three-bedroom house or for a two-family house, seven hundred fifty (750) gallons and proportional increases in size for additional number of persons.
Details of construction: See State Code.
Porous drain tile, at least four (4) inches in diameter, laid with open joints one-fourth (1/4) to three-fourths (3/4) of an inch in shallow trenches twelve (12) to thirty (30) inches wide, and twelve (12) to twenty-four (24) inches deep, with greater depths permissible where justified by topography and soil.
During construction, avoid compacting or sealing the soil at the bottom and sides of the trench.
Joints shall be covered with strips of tar paper or other suitable material.
The trench bottom should be approximately level, should follow ground contours and be at least eighteen (18) inches above the maximum water table.
Tile shall be laid on at least ten (10) inches of stone for a twelve- to twenty-inch trench; for wider trenches, stone depth shall be one and one-half (11/2) times the trench width. Stone is to continue to two (2) inches above tile.
Tile grade shall not exceed six (6) inches per one hundred (100) feet.
Cover stone with tar paper or a layer of hay to keep out backfill.
The length of a single tile lateral shall not exceed seventy-five (75) feet; with dosing apparatus, up to one hundred (100) feet in length.
Spacing between trenches shall be at least three (3) times the width of the trench.
A drop-manhole construction or distribution box shall be used if the slope of the main header exceeds one (1) foot per one hundred (100) feet.
A distribution box is to be installed at the head of each disposal field.
The invert of all outlets shall be level, and the inlet invert shall be at least one (1) inch above the outlets.
Where space between the trenches is also excavated and backfilled with stone, only one-third (1/3) of the total bottom area shall be considered effective.
Leaching area depends on the soil and number of persons using the system, as follows:
Leaching cesspools should never be used where there is danger of polluting underground waters.
Size requirements for leaching cesspools.
Where more than one (1) cesspool is required, the distance between them shall be at least three (3) times the diameter of the larger cesspool.
Cesspools may be built of stone or concrete block laid with loose joints below the maximum liquid level. No bottom is necessary.
Walls should be surrounded by at least twelve (12) inches of screened gravel or broken stone.
Cesspools should be covered with concrete slab or other structure and made accessible for inspection.
Bottoms of cesspools should be at least two (2) feet above the maximum groundwater level.
For tile fields:
Dig or bore a hole five (5) inches to twelve (12) inches in diameter and to the depth of the proposed trench.
Carefully scratch the bottom and sides of the hole with a knife blade or other sharp instrument to remove smeared surfaces and expose natural soil structure. Remove all loose material from the bottom, and add one (1) or two (2) inches of coarse sand or fine gravel.
Carefully fill the hole with clear water to a minimum depth of twelve (12) inches over the sand. Refill the hole if and as necessary to keep water in the hole for at least four (4) hours, except in coarse sandy soils where such soaking is not needed. (The purpose of soaking the soil is to promote swelling of clay particles such as takes place in the wettest season of the year.)
Measure the seepage rate as follows: With at least twelve (12) inches of water in the test bole, measure the rate of drop in water level over a period of thirty (30) to sixty (60) minutes. The minimum uniform rate should be used in calculating seepage area required.
For leaching cesspools:
Seepage tests for cesspools are difficult to make because of the depth involved and the several soil strata that may be encountered which may vary in seepage rate.
Best results will be obtained by making separate tests for each soil strata, using the technique described for tests for tile fields. For example, one (1) pit should be dug to a depth of about two (2) feet, and the tests made. A second pit to about four (4) feet, a third pit to about six (6) feet, and tests made in each. Except where the bottom is very sandy and gravelly, most of the seepage in a cesspool takes place in the walls of the pit.