Exception: Where suitable sites outside of flood hazard areas are not available, disposal systems shall be permitted to be located in flood hazard areas on sites where the effects of inundation under conditions of the design flood are minimized.
|MINIMUM HORIZONTAL DISTANCE||BUILDING SEWER||SEPTIC TANK||DISPOSAL FIELD||SEEPAGE PIT OR CESSPOOL|
|Building or structures1||2 feet||5 feet||8 feet||8 feet|
|Property line adjoining private property||Clear2||5 feet||5 feet||8 feet|
|Water supply wells||50 feet3||50 feet||100 feet||150 feet|
|Streams and other bodies of water||50 feet||50 feet||100 feet7||150 feet7|
|Trees||—||10 feet||—||10 feet|
|Seepage pits or cesspools8||—||5 feet||5 feet||12 feet|
|Disposal field8||—||5 feet||4 feet4||5 feet|
|On-site domestic water service line||1 foot5||5 feet||5 feet||5 feet|
|Distribution box||—||—||5 feet||5 feet|
|Pressure public water main||10 feet6||10 feet||10 feet||10 feet|
For SI units: 1 foot = 304.8 mm
1 Including porches and steps, whether covered or uncovered, breezeways, roofed porte cocheres, roofed patios, carports, covered walks, covered driveways, and similar structures or appurtenances.
2 See Section 312.3.
3 Drainage piping shall clear domestic water supply wells by not less than 50 feet (15 240 mm). This distance shall be permitted to be reduced to not less than 25 feet (7620 mm) where the drainage piping is constructed of materials approved for use within a building.
5 See Section 720.0.
6 For parallel construction — For crossings, approval by the Health Department shall be required.
7 These minimum clear horizontal distances shall also apply to disposal fields, seepage pits, and the mean high-tide line.
8 Where disposal fields, seepage pits, or both are installed in sloping ground, the minimum horizontal distance between any part of the leaching system and ground surface shall be 15 feet (4572 mm).
Nothing contained in this code shall be construed to prohibit the use of all or part of an abutting lot to provide additional space for a private sewage disposal system or part thereof where proper cause, transfer of ownership, or change of boundary not in violation of other requirements has been first established to the satisfaction of the Authority Having Jurisdiction. The instrument recording such action shall constitute an agreement with the Authority Having Jurisdiction, which shall clearly state and show that the areas so joined or used shall be maintained as a unit during the time they are so used. Such agreement shall be recorded in the office of the County Recorder as part of the conditions of ownership of said properties and shall be binding on heirs, successors, and assigns to such properties. A copy of the instrument recording such proceedings shall be filed with the Authority Having Jurisdiction.
H 101.10 Additional Requirements. Nothing contained in this appendix shall be construed to prevent the Authority Having Jurisdiction from requiring compliance with additional requirements than those contained herein, where such additional requirements are essential to maintaining a safe and sanitary condition.
H 101.11 Alternate Systems. Alternate systems shall be permitted to be used by special permission of the Authority Having Jurisdiction after being satisfied with their adequacy. This authorization is based on extensive field and test data from conditions similar to those at the proposed site or requires such additional data as necessary to assure that the alternate system will produce continuous and long-range results at the proposed site, not less than equivalent to systems which are specifically authorized.
Where demonstration systems are to be considered for installation, conditions for installation, maintenance, and monitoring at each such site shall first be established by the Authority Having Jurisdiction.
Approved aerobic systems shall be permitted to be substituted for conventional septic tanks provided the Authority Having Jurisdiction is satisfied that such systems will produce results not less than equivalent to septic tanks, whether their aeration systems are operating or not.
|SINGLE-FAMILY DWELLINGS - NUMBER OF BEDROOMS||MULTIPLE DWELLING UNITS OR APARTMENTS - ONE BEDROOM EACH||OTHER USES: MAXIMUM FIXTURE UNITS SERVED PER TABLE 702.1||MINIMUM SEPTIC TANK CAPACITY (gallons)|
|1 or 2||—||15||750|
|5 or 6||3||33||1500|
For SI units: 1 gallon = 3.785 L
1 Extra bedroom, 150 gallons (568 L) each.
2 Extra dwelling units over 10: 250 gallons (946 L) each.
TABLE H 201.1(2)
DESIGN CRITERIA OF FIVE TYPICAL SOILS
|TYPE OF SOIL||REQUIRED SQUARE FEET OF LEACHING AREA PER 100 GALLONS||MAXIMUM ABSORPTION CAPACITY IN GALLONS PER SQUARE FEET OF LEACHING AREA FOR A 24 HOUR PERIOD|
|Coarse sand or gravel||20||5.0|
|Sandy loam or sandy clay||40||2.5|
|Clay with considerable sand or gravel||90||1.1|
|Clay with small amount of sand or gravel||120||0.8|
For SI units: 1 square foot = 0.0929 m2, 1 gallon = 3.785 L, 1 gallon per square foot = 40.7 L/m2
|REQUIRED SQUARE FEET OF LEACHING AREA PER 100 GALLONS SEPTIC TANK CAPACITY |
(square feet per 100 gallons)
|MAXIMUM SEPTIC TANK SIZE ALLOWABLE |
For SI units: 1 square foot per 100 gallons = 0.000245 m2/L, 1 gallon = 3.785 L
|TYPE OF OCCUPANCY||GALLONS PER DAY|
|Airports (per employee)||15|
|Airports (per passenger)||5|
|Auto washers — check with equipment manufacturer||-|
|Bowling alleys — with snack bar only (per lane)||75|
|Campground — with central comfort station (per person)||35|
|Campground — with flush toilets — no showers (per person)||25|
|Camps (day) — no meals served (per person)||15|
|Camps (summer and seasonal camps) — (per person)||50|
|Churches — sanctuary (per seat)||5|
|Churches — with kitchen waste (per seat)||7|
|Dance halls — (per person)||5|
|Factories — no showers (per employee)||25|
|Factories — with showers (per employee)||35|
|Factories — with cafeteria (per employee)||5|
|Hospitals — (per bed)||250|
|Hospitals — kitchen waste only (per bed)||25|
|Hospitals — laundry waste only (per bed)||40|
|Hotels — no kitchen waste (per bed)||60|
|Institutions — resident (per person)||75|
|Nursing home — (per person)||125|
|Rest home — (per person)||125|
|Laundries — self-service with minimum 10 hours per day (per wash cycle)||50|
|Laundries — commercial check with manufacturer's specification||-|
|Motel (per bed space)||50|
|Motel — with kitchen (per bed space)||60|
|Offices — (per employee)||20|
|Parks — mobile homes (per space)||250|
|Parks (picnic) — with toilets only (per parking space)||20|
|Parks (recreational vehicles) — without water hook-up (per space)||75|
|Parks (recreational vehicles) — with water and sewer hook-up (per space)||100|
|Restaurants — cafeteria (per employee)||20|
|Restaurants — with toilet waste (per customer)||7|
|Restaurants — with kitchen waste (per meal)||6|
|Restaurants — with kitchen waste disposable service (per meal)||2|
|Restaurants — with garbage disposal (per meal)||1|
|Restaurants — with cocktail lounge (per customer)||2|
|Schools staff and office (per person)||20|
|Schools — elementary (per student)||15|
|Schools — intermediate and high (per student)||20|
|Schools — with gym and showers (per student)||5|
|Schools — with cafeteria (per student)||3|
|Schools (boarding) — total waste (per person)||100|
|Service station — with toilets for 1st bay||1000|
|Service station — with toilets for each additional bay||500|
|Stores — (per employee)||20|
|Stores — with public restrooms (per 10 square feet of floor space)||1|
|Swimming pools — public (per person)||10|
|Theaters — auditoriums (per seat)||5|
|Theaters — with drive-in (per space)||10|
For SI units: 1 square foot = 0.0929 m2, 1 gallon per day = 3.785 L/day
Flow × 1.5 = septic tank size
Flow × 0.75 + 1125 = septic tank size
(c) Secondary system shall be sized for total flow per 24 hours.
2 See Section H 201.1.
3 Because of the many variables encountered, it is not possible to set absolute values for waste/sewage flow rates for all situations. The designer should evaluate each situation and, where figures in this table need modification; they should be made with the concurrence of the Authority Having Jurisdiction.
- Where disposal fields are installed, not less than 150 square feet (13.9 m2) of trench bottom shall be provided for each system exclusive of any hard pan, rock, clay, or other impervious formations. Sidewall area more than the required 12 inches (305 mm) and not exceeding 36 inches (914 mm) below the leach line shall be permitted to be added to the trench bottom area where computing absorption areas.
- Where leaching beds are permitted instead of trenches, the area of each such bed shall be not less than 50 percent greater than the tabular requirements for trenches. Perimeter sidewall area more than the required 12 inches (305 mm) and not exceeding 36 inches (914 mm) below the leach line shall be permitted to be added to the trench bottom area where computing absorption areas.
- No excavation for a leach line or leach bed shall be located within 5 feet (1524 mm) of the water table nor to a depth where sewage is capable of contaminating the underground water stratum that is usable for domestic purposes.
Exception: In areas where the records or data indicate that the groundwaters are grossly degraded, the 5 foot (1524 mm) separation requirement shall be permitted to be reduced by the Authority Having Jurisdiction. The applicant shall supply evidence of groundwater depth to the satisfaction of the Authority Having Jurisdiction.
- The minimum effective absorption area in any seepage pit shall be calculated as the excavated sidewall area below the inlet exclusive of any hardpan, rock, clay, or other impervious formations. The minimum required area of porous formation shall be provided in one or more seepage pits. No excavation shall extend within 10 feet (3048 mm) of the water table nor to a depth where sewage is capable of contaminating underground water stratum that is usable for domestic purposes.
Exception: In areas where the records or data indicate that the groundwaters are grossly degraded, the 10 foot (3048 mm) separation requirement shall be permitted to be reduced by the Authority Having Jurisdiction.
The applicant shall supply evidence of groundwater depth to the satisfaction of the Authority Having Jurisdiction.
- Leaching chambers that comply with IAPMO PS 63 and bundled expanded polystyrene synthetic aggregate units that comply with IAPMO IGC 276 shall be sized using the required area calculated using Table H 201.1 (2) with a 0.70 multiplier.
H 501.10 Partitions and Baffles. Partitions or baffles between compartments shall be of solid, durable material and shall extend not less than 4 inches (102 mm) above the liquid level. The transfer port between compartments shall be a minimum size equivalent to the tank inlet, but in no case less than 4 inches (102 mm) in size, shall be installed in the inlet compartment side of the baffle so that the entry into the port is placed 65 percent to 75 percent in the depth of the liquid. Wooden baffles are prohibited.
H 501.11 Structural Design. The structural design of septic tanks shall comply with the following requirements:
- Each such tank shall be structurally designed to withstand all anticipated earth or other loads. Septic tank covers shall be capable of supporting an earth load of not less than 500 pounds per square foot (lb/ft2) (2441 kg/m2) where the maximum coverage does not exceed 3 feet (914 mm).
- In flood hazard areas, tanks shall be anchored to counter buoyant forces during conditions of the design flood. The vent termination and service manhole of the tank shall be not less than 2 feet (610 mm) above the design flood elevation or fitted with covers designed to prevent the inflow of floodwater or the outflow of the contents of the tanks during conditions of the design flood.
H 501.12 Manholes. Septic tanks installed under concrete or blacktop paving shall have the required manholes accessible by extending the manhole openings to grade in a manner acceptable to the Authority Having Jurisdiction.
H 501.13 Materials. The materials used for constructing a septic tank shall be in accordance with the following:
- Materials used in constructing a concrete septic tank shall be in accordance with applicable standards in Table 1701.1.
- The minimum wall thickness of a steel septic tank shall be number 12 U.S. gauge (0.109 of an inch) (2.77 mm), and each such tank shall be protected from corrosion both externally and internally by an approved bituminous coating or by other acceptable means.
- Septic tanks constructed of alternate materials shall be permitted to be approved by the Authority Having Jurisdiction where in accordance with approved applicable standards. Wooden septic tanks shall be prohibited.
- Manufactured or prefabricated septic tanks shall comply with approved applicable standards and be approved by the Authority Having Jurisdiction. Prefabricated bituminous coated septic tanks shall comply with UL 70.
- Independent laboratory tests and engineering calculations certifying the tank capacity and structural stability shall be provided as required by the Authority Having Jurisdiction.
Exception: Listed or approved plastic leaching chambers and bundled expanded polystyrene synthetic aggregate units shall be permitted to be used in lieu of pipe and filter material. Chamber and bundled expanded polystyrene synthetic aggregate unit installations shall follow the rules for disposal fields, where applicable, and shall be in accordance with the manufacturer's instructions.
TABLE H 601.9
GENERAL DISPOSAL FIELD REQUIREMENTS
|Number of drain lines per field||1||-|
|Length of each line||-||100 feet|
|Bottom width of trench||18 inches||36 inches|
|Spacing of lines, center-to-center||6 feet||-|
|Depth of earth cover of lines (preferred 18 inches)||12 inches||-|
|Grade of lines||level||3 inches per 100 feet|
|Filter material under drain lines||12 inches||-|
|Filter material over drain lines||2 inches||-|
For SI units: l inch = 25.4 mm, l foot = 304.8 mm, l inch per foot = 83.3 mm/m
Minimum spacing between trenches or leaching beds shall be not less than 4 feet (1219 mm) plus 2 feet (610 mm) for each additional foot (305 mm) of depth more than 1 foot (305 mm) below the bottom of the drain line. Distribution drain lines in leaching beds shall be not more than 6 feet (1829 mm) apart on centers, and no part of the perimeter of the leaching bed shall exceed 3 feet (914 mm) from a distribution drain line. Disposal fields, trenches, and leaching beds shall not be paved over or covered by concrete or a material that is capable of reducing or inhibiting a possible evaporation of sewer effluent.
H 601.10 Joints. Where necessary on sloping ground to prevent excessive line slope, leach lines or leach beds shall be stepped. The lines between each horizontal section shall be made with watertight joints and shall be designed, so each horizontal leaching trench or bed shall be utilized to the maximum capacity before the effluent shall pass to the next lower leach line or bed. The lines between each horizontal leaching section shall be made with approved watertight joints and installed on the natural or unfilled ground.
- Approved-type hard-burned clay brick or solid concrete brick or block laid in cement mortar.
- Approved brick or block laid dry. In both of the above methods, an approved cement mortar covering of not less than 2 inches (51 mm) in thickness shall be applied, said covering to extend not less than 6 inches (152 mm) beyond the sidewalls of the pit.
- Approved-type one or two-piece reinforced concrete slabs of not less than 2500 lb/in2 (1 757 672 kg/m2) minimum compressive strength, not less than 5 inches (127 mm) thick, and designed to support an earth load of not less than 400 pounds per square foot (lb/ft2) (1953 kg/m2). Each such cover shall be provided with a 9 inch (229 mm) minimum inspection hole with plug or cover and shall be coated on the underside with an approved bituminous or other nonpermeable protective compound.
Exception: Where using a one- or two-piece concrete slab cover inlet, fitting shall be permitted to be a one-fourth bend fitting discharging through an opening in the top of the slab cover. On multiple seepage pit installations, the outlet fittings shall comply with Section H 701.2 of this appendix.
CHART H 901.7
RECOMMENDED DESIGN CRITERIA
|GREASE AND GARBAGE, COMMERCIAL KITCHENS|
|Number of meals per peak hour||×||Waste flow rate1||×||Retention time2||×||Storage factor3||=||Interceptor size |
|SAND-SILT OIL, AUTO WASHERS|
|Number of vehicles per hour||×||Waste flow rate||×||Retention time2||×||Storage factor3||=||Interceptor size |
|SILT-LINT GREASE, LAUNDRIES, LAUNDROMATS|
|Number of machines||×||2 cycles per hour||×||Waste flow rate1||×||Retention time2||=||Storage factor3||=||Interceptor size |
2 Retention Times:
(a) Kitchen (commercial) — with dishwasher, garbage disposal, or both = 2.5 hours
(b) Kitchen (single service) — with garbage disposal = 1.5 hours
(c) Auto Washers (sand-silt oil) = 2.0 hours
(d) Laundries/Laundromats = 2.0 hours
3 Storage Factors:
(a) Kitchen (commercial) — with 8 hours operation = 1
(b) Kitchen (commercial) — with 16 hours operation = 2
(c) Kitchen (commercial) — with 24 hours operation = 3
(d) Kitchen (single service) = 1.5
(e) Auto Washers (sand-silt oil) — with self service = 1.5
(e) Auto Washers (sand-silt oil) — with employee operated = 2
(d) Laundries/Laundromats — with rock filter = 1.5 hours
- Applicable provisions of Section 105.0 of this code and this appendix shall be required. Plans shall be required in accordance with Section 103.3 of this code.
- System components shall be properly identified as to manufacturer. Septic tanks or other primary systems shall have the rated capacity permanently marked on the unit.
- Septic tanks or other primary systems shall be installed on dry, level, well-compacted soil.
- Where design is predicated on soil tests, the system shall be installed at the same location and depth as the tested area.
- Septic tanks or other primary components shall be filled with water to flow line before requesting an inspection. Seams or joints shall be left exposed (except the bottom), and the tank shall remain watertight.
- A flow test shall be performed through the system to the point of effluent disposal. All lines and components shall be watertight. Capacities required air space, and fittings shall comply with the provisions outlined in this appendix.
- Plot plan drawn to scale, completely dimensioned, showing direction and approximate slope of surface, location of present or proposed retaining walls, drainage channels, water supply lines or wells, paved areas and structures on the plot, number of bedrooms or plumbing fixtures in each structure, and location of the private sewage disposal system with relation to lot lines and structures.
- Details of construction necessary to ensure compliance with the requirements of this appendix together with a full description of the complete installation including quality, kind, and grade of materials, equipment, construction, workmanship, and methods of assembly and installation.
- A log of soil formations and groundwater levels as determined by test holes dug in close proximity to a proposed seepage pit or disposal field, together with a statement of water absorption characteristics of the soil at the proposed site, as determined by approved percolation tests.
"The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."
The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.