RNPCP - Appendix B: Private Sewage Disposal Systems

Location, Soil porosity, and Groundwater level

B1 - General

The private sewage disposal system will be determined on the basis of _________, __________, and ___________, and shall be designed to receive all sewage from the property.

- subsurface disposal field

- into one (1) or more seepage pits, or

- into a combination of both

B1 - General

The private sewage disposal system shall consist of a septic tank with effluent discharging into a:

1. ___________

2. ___________

3. ___________

- number of Bedrooms or apartment units in dwelling occupancies and

- the estimated wastewater design Flow rate

- the number of plumbing Fixture units

B2 - Capacity of Septic Tanks

The liquid capacity of all septic tanks shall conform to Tables B-2 and B-3 as determined by the:

1. ___________

2. ___________

3. ___________

whichever is greater in other building occupancies.

soil structure classification

B2 - Capacity of Septic Tanks

The capacity of any one septic tank and its drainage system shall be limited by the ________________

- required septic tank Capacity in liters

- estimated wastewater/sewage Flow rate

B3 - Area of Disposal Fields and Seepage Pits

The minimum effective absorption area in disposal fields (in m²), and in seepage pits (in m² of side wall), shall be predicated on the:

1. ______________

2. ____________

whichever is greater

14 m²

B3 - Area of Disposal Fields and Seepage Pits

When disposal fields are installed, a minimum of __________ of trench bottom shall be provided for each system, exclusive of any hard pan, rock, clay, or other impervious formations.

fifty (50) percent

B3 - Area of Disposal Fields and Seepage Pits

Where leaching beds are permitted in lieu of trenches, the area of each such bed shall be at least __________ greater than the tubular requirements for trenches.

305 - 915 mm

(304.8 mm to 914.4 mm)

B3 - Area of Disposal Fields and Seepage Pits

Perimeter side wall area in excess of the required _______ and not to exceed ______ below the leach line may be added to the trench bottom area when computing absorption areas.

1.5 m

In areas where the records or data indicate that the groundwater levels are grossly degraded, the 3 m separation requirement may be reduced by the Administrative Authority. The applicant shall supply evidence of groundwater depth to the satisfaction of the Administrative Authority.

B3 - Area of Disposal Fields and Seepage Pits

No excavation for a leach line or leach bed shall extend within _____ of the water table nor to a depth where sewage may contaminate the underground water stratum that is usable for domestic purposes.

3 m

In areas where the records or data indicate that the groundwater levels are grossly degraded, the 3 m separation requirement may be reduced by the Administrative Authority. The applicant shall supply evidence of groundwater depth to the satisfaction of the Administrative Authority.

B3 - Area of Disposal Fields and Seepage Pits

No excavation shall for a seepage pit extend within _____ of the water table nor to a depth where sewage may contaminate the underground water stratum that is usable for domestic purposes.

percolation tests

In order to determine the absorption qualities of questionable soils, the proposed site shall be subjected to ___________ acceptable to the AA

2 compartments

B5 - Septic Tank Construction

Septic tanks shall have a minimum of ____ compartments

2/3

B5 - Septic Tank Construction

The inlet compartment of any septic tank shall be not less than ______ of the total capacity of the tank

2 m³ = min volume of inlet compartment

B5 - Septic Tank Construction

The inlet compartment of any septic tank shall be not less than _____ liquid capacity

0.9 m x 1.5 m = min. dimension of inlet compartment

B5 - Septic Tank Construction

The inlet compartment of any septic tank shall be at least _______ in width and _______ in length.

600 mm - 1800 mm = liquid depth of septic tank compartment

B5 - Septic Tank Construction

The liquid depth shall be no less than _____ nor more than _____.

1 m³ = min. volume of secondary compartment

B5 - Septic Tank Construction

The secondary compartment of any septic tank shall have a minimum capacity of _____

1/3 = max. capacity of secondary compartment

B5 - Septic Tank Construction

The secondary compartment of any septic tank shall have a maximum capacity of _____ of the total capacity of the tank.

1.5 m = min. dimension of secondary compartment of 6 cum and above septic tanks

B5 - Septic Tank Construction

In septic tanks having over 6 m³ capacity, the secondary compartment may be not less than ________ in length.

508 mm = min. dimension of septic tank manhole

B5 - Septic Tank Construction

Access to each septic tank shall be provided by at least two (2) manholes, _____ in minimum dimension, or by an equivalent removable cover slab.

One access manhole shall be located over the inlet, and one (1) access manhole shall be located over the outlet.

above 3.7 m = additional manhole needed

B5 - Septic Tank Construction

Wherever the first compartment exceeds _____ in length, an additional manhole shall be provided over the baffle wall.

104.6 mm = min. diameter of vertical leg of inlet/outlet

B5 - Septic Tank Construction

The vertical leg of a round inlet and outlet fitting shall not be less in size than the connecting sewer pipe, nor less than _____ mm.

106.6 mm = min. horizontal distance from inlet/outlet invert to baffle type fitting

B5 - Septic Tank Construction

A baffle-type fitting shall have the equivalent cross-sectional area of the connecting sewer pipe and not less than a _______ horizontal dimension when measured at the inlet and outlet pipe inverts.

101.6 mm = min. extension of baffle fitting above water surface

B5 - Septic Tank Construction

The inlet and outlet pipe or baffle shall extend at least ______ above the water surface.

304.8 mm = min. extension of baffle fitting below water surface

B5 - Septic Tank Construction

The inlet and outlet pipe or baffle shall extend at least below the water surface. The invert of the inlet pipe shall be at a level not less than 50.8 mm above the invert of the outlet pipe.

50.8 mm = min. distance between invert of inlet and outlet pipe

B5 - Septic Tank Construction

The invert of the inlet pipe shall be at a level not less than _______ above the invert of the outlet pipe.

228.6 mm = min. extension of sidewalls above the liquid

B5 - Septic Tank Construction

The side walls shall extend at least _____ above the liquid depth.

50.8 mm = min. vertical distance between baffle opening and septic tank cover

B5 - Septic Tank Construction

The cover of the septic tank shall be at least ________ above the back vent openings

14.4 kPa = min. earth load of septic tank covers (< 9 sqm)

(2.1 psi)

B5 - Septic Tank Construction

All septic tank covers shall be capable of supporting an earth load of not less than ______ when the maximum coverage does not exceed 9 m²

101.6 mm = min. distance of baffles between compartments above the liquid level

B5 - Septic Tank Construction

Partitions or baffles between compartments shall be of solid durable material and shall extend at least _________ above the liquid level.

104.6 mm = min. diameter of vertical leg of inlet/outlet

B5 - Septic Tank Construction

An inverted fitting equivalent in size to the tank inlet, but in no case less than _________ in size, shall be installed in the inlet compartment side of the baffle. with the

midway of liquid depth

B5 - Septic Tank Construction

The bottom of the fitting shall be placed __________ in the depth of the liquid. Wooden baffles are prohibited

101.6 mm = min. extension of coating below the water line (in concrete septic tanks)

(4 inches)

B5 - Septic Tank Construction

All concrete septic tanks shall be protected from corrosion by coating with an approved bituminous coating or by other acceptable means. The coating shall extend to at least ________ below the water line and shall cover all of the internal area above that point.

No. 12 U.S. gauge (0.109) (2.8 mm)

B5 - Septic Tank Construction

The minimum wall thickness of any steel septic tank shall be ___________ , and each such tank shall be protected from corrosion, both externally and internally, by an approved bituminous coating or by other acceptable means.

sufficient openings are available for the distribution of the effluent into the trench area.

B6 - Disposal Fields

Distribution lines shall be constructed of

- clay tile laid with open joints

- perforated clay pipe

- perforated bituminous fiber pipe

- perforated high-density polyethylene pipe

- perforated ABS pipe

- perforated PVC pipe,

- or other approved materials, provided that...

25.4 mm = min. depth of filter material

B6 - Disposal Fields

Before placing filter material or drain lines in a prepared excavation, any smeared or compacted surfaces shall be removed from trenches by raking to a depth of _________, and the loose material removed.

19.1 mm to 63.5 mm = acceptable size of filter material for disposal fields

B6 - Disposal Fields

Clean stone, gravel, slag, or similar filter material acceptable to the Administrative Authority, varying in size from __________, shall be placed in the trench to the depth and grade required by this standard.

1.5 meters = max. distance of trenches from seepage pits

B6 - Disposal Fields

When seepage pits are used in combination with disposal fields, the filter material in the trenches shall terminate at least _________ from the pit excavation.

dosing tank

B6 - Disposal Fields

When the quantity of sewage exceeds the amount that can be disposed of in 152.4 linear meters of each line, a __________ shall be used.

three (3) or four (4) hours.

B6 - Disposal Fields

Dosing tanks shall be equipped with an automatic siphon or pump that discharges the tank once every ___________

60% - 75% of the interior capacity of the pipe

B6 - Disposal Fields

Dosing tanks shall have a capacity equal to __________ of the interior capacity of the pipe to be discharged at one time.

two (2) siphons or pumps

B6 - Disposal Fields

Where the total length of pipe exceeds 304.8 linear meters, the dosing tank shall be provided with ________ siphons or pumps dosing alternately, with each serving one-half (1/2) of the leach field.

B6 - Disposal Fields

Minimum spacing between trenches or leaching beds shall be 1.2 m plus 6 m for each additional 3 m of depth in excess of 3 m below the bottom of the drain line.

1.8 m O.C. = distance between distribution lines

B6 - Disposal Fields

Distribution drain lines in leaching beds shall be no more than ________ apart on centers.

900 mm = max. distance of leaching bed to distribution drain line

B6 - Disposal Fields

No part of the perimeter of the leaching bed shall be more than ______ from a distribution drain line.

Refer to table

B6 - Disposal Fields

Disposal fields shall be constructed as follows:

- quantity of liquid waste discharged into them

- characteristics and porosity of the surrounding soil.

B7 - Seepage Pits

The capacity of seepage pits shall be based on the:

1. ______

2. ______

304.8 mm = extension of vented leg fitting below inlet fitting

(12 inches)

B7 - Seepage Pits

Multiple seepage pit installations shall be served through an approved distribution box or be connected in series by means of a watertight connection. The outlet from the pit shall have an approved vented leg fitting extending at least _______ below the inlet fitting, with the connection made in undisturbed or uncompacted soil.

2.2 meters = min. diameter of seepage pit

B7 - Seepage Pits

Each seepage pit shall be circular in shape and shall have an excavated diameter of not less than __________

1.8 meters diameter seepage pit = approval needed

B7 - Seepage Pits

Approval shall be obtained prior to construction for any pit having an excavated diameter greater than _________

17,225 kPa.

(2500 psi)

B7 - Seepage Pits

All brick or block used in seepage pit construction shall have a minimum compressive strength of __________

3 meters = min. sidewall depth of seepage pits below the inlet

B7 - Seepage Pits

Each seepage pit shall have a minimum sidewall (not including the arch) of _________ below the inlet.

152.4 mm = min depth of 19.1 mm gravel of rock in excavation voids

(6 inches)

B7 - Seepage Pits

Excavation voids behind the brick, block, or concrete liner shall have a minimum of _______ of clean 19.1 mm gravel or rock.

1. temporary expedient pending the construction of a public sewer

2. overflow facility when installed in conjunction with an existing cesspool

3. means of sewage disposal for limited, minor, or temporary uses

B8 - Cesspools

A cesspool shall be considered only as a:

1. ________

2. ________

3. ________ when first approved by the Administrative Authority.

two (2) years = Min. time for public sewer availability, allowing cesspools without septic tanks

B8 - Cesspools

Where it is established that a public sewer system will be available in less than ___________ and soil and groundwater conditions are favorable to cesspool disposal, cesspools without septic tanks may be installed for single-family dwellings or for other limited uses when first approved by the Administrative Authority.

6.1 meters = minimum sidewall depth of cesspool below the inlet

(except when a stratum of gravel or equally pervious material of 1.2 meters in thickness is found, then 3.1 meters minimum)

B8 - Cesspools

Each cesspool, when permitted, shall have a minimum sidewall depth (not including arch) of __________ below the inlet

When a stratum of gravel or equally pervious material of 1.2 m in thickness is found, the depth of such sidewall need not be more than 0.91 m below the inlet.

152.4 mm = vertical clearance of the inlet above the outlet for overflow cesspools

B8 - Cesspools

When overflow cesspools or seepage pits are added to existing installations, the effluent shall leave the existing pit through an approved vented pipe extending at least 304.8 mm downward into such existing pit and having its outlet flow line at least _______ below the inlet.

interceptor

B9 - Commercial or Industrial Special Liquid Waste Disposal

When liquid wastes containing excessive amounts of:

- grease,

- garbage,

- flammable wastes,

- sand, or

- other ingredients which may affect the operation of a private sewage disposal system,

a/an _______________ for such wastes shall be installed.

two (2)

B9 - Commercial or Industrial Special Liquid Waste Disposal

Interceptors shall be of approved design and have not less than ____________ compartment/s.

as close as possible

B9 - Commercial or Industrial Special Liquid Waste Disposal

Interceptors shall be located ________ to the source and be accessible for servicing.

All necessary manholes for servicing shall be at grade level and be gastight.

Waste discharge from interceptors may be connected to a septic tank or other primary system, or be disposed of into a separate disposal system.

filled with water to flow line

B10 - Inspection and Testing

Septic tanks or other primary components shall be _________________ prior to requesting inspection.

1.5 meters of property line = abandoned house sewers required to be capped/plugged

B11 - Abandoned Sewers and Sewage Disposal Facilities

Every abandoned building (house) sewer, or part thereof, shall be plugged or capped in an approved manner within __________ of the property line.

thirty (30) days = max. time period for filling all abandoned sewer/disposal facilities

B11 - Abandoned Sewers and Sewage Disposal Facilities

Where disposal facilities are abandoned consequent to connecting any premises with the public sewer, the permittee making the connection shall fill all abandoned facilities as required by the AA within ______ from the time of connecting to the public sewer.