§ 8001-01 Individual Private On-Site Sewage Disposal Systems.
RCNY § 8001-01
(a)Applicability and scope. This rule governs the construction and installation of new individual private on-site sewage disposal systems and alteration and maintenance of existing individual private on-site sewage disposal systems. This rule applies to on-site wastewater treatment systems serving residential (one- and two-family) and non-residential (other than one- and two-family) properties receiving less than 1,000 gallons of sewage per day which does not include industrial wastes or other wastes as defined in the Code of Federal Regulations, the Clean Water Act, the Safe Drinking Water Act, the Insecticide, Fungicide and Rodenticide Act, the Toxic Substances Control Act, the New York State Environmental Conservation Law and the New York Code of Rules and Regulations. Exception: Pursuant to ECL § 17-0803 and 6 NYCRR 750-1.4, the New York State Department of Environmental Conservation (DEC) has the authority to issue permits for a new or modified disposal system discharging any amount of sewage with the presence of such industrial waste or other wastes, or for a residential or non-residential use whose total discharge of sewage is 1,000 gallons or more per day. DOB will not issue a permit to construct and use any such system until a DEC State Pollutant Discharge Elimination System (SPDES) permit is provided to the department.
(b)References. See 10 NYCRR Part 75 and Appendix 75-A of the New York State Department of Health (NYS DOH) rules, DEC's Design Standards for Intermediate Sized Wastewater Treatment Systems (March 5, 2014) and Section 701.2 of the New York City Plumbing Code (PC).
(c)Definitions. For the purposes of this section, the following terms have the following meanings: Absorption area. An area to which wastewater is distributed for infiltration to the soil. Aggregate. Washed gravel or crushed stone 3/4 - 1 1/2 inches in diameter. Application rate. The rate at which septic tank effluent is applied to a subsurface absorption area, for design purposes, expressed in gallons per day per square foot (GPD/sq. ft.). Baffle. A flow deflecting device used in septic tanks and distribution boxes to inhibit the discharge of floating solids, reduce the amount of settle-able solids that exit, and reduce the exit velocity of the wastewater. Cesspool. A covered excavation in the ground that receives the discharge of domestic sewage or other organic wastes from a drainage system, so designated as to retain the organic matter and solids, but permitting the liquid to seep through the bottom and sides. Cleanout. An opening providing access to part of the sewage system. Daily flow rate (Q). The design flow of the system expressed in units of Gallons Per Day (GPD). Distribution box. A chamber into which the septic effluent discharges and from which the sewage enters the subsurface distribution lines. Distribution line. The perforated pipe used to distribute wastewater to the absorption area. Gas deflection baffle. A device on the outlet of a septic tank which deflects gas bubbles away from the outlet and reduces the carryover of solid particles from the septic tank. GPD. Gallons per day. GPF. Gallons per flush. Unit used to describe amount of water used in each toilet flush. GPM. Gallons per minute. Unit used to describe flow rate of plumbing fixtures. Groundwater. Subsurface water occupying the saturation zone from which wells and springs are fed. Individual private on-site sewage disposal system. A system designed for use apart from a public sewer for the disposal of sewage by means of piping and a septic tank or tanks that discharge into a disposal field or seepage pit and serving properties discharging less than 1,000 gallons of sewage per day. Infiltration. The flow or movement of water into the interstices or pores of a soil through the soil interface. Invert. The floor, bottom, or lowest point of the inside cross section of a pipe. Percolation. The movement of water through the pores of a soil or other porous medium following infiltration through the soil interface. Piping. Piping includes fittings, valves, and other accessories or appurtenances required to make a complete installation. Registered design professional. An architect or engineer licensed and registered under the New York State Education Law. Seepage pit. A covered pit with open jointed or perforated lining into which the septic tank effluent is discharged. The liquid portion of the sewage seeps into the surrounding porous soil. The remaining solids or sludge is retained in the pit. Septic tank. A watertight receptacle that receives the discharge of a drainage system or part thereof, and is designed and constructed so as to separate solids from the liquid, digest organic matter during a period of detention, and allow the liquids to discharge into the soil outside of the tank through a system of open-joint or perforated piping, or seepage pit. Sewage. The combination of human and household waste with water which is discharged to the home plumbing system including the waste from a flush toilet, bath, sink, lavatory, dishwashing or laundry machine, or the water-carried waste from any other fixture, equipment or machine. Stack. A general term for any vertical line of soil, waste, vent or inside conductor piping that extends through at least one story with or without offsets. Wastewater. Any water discharged from a house through a plumbing fixture to include, but not limited to, sewage and any water or waste from a device (e.g., water softener brine) which is produced in the house or property. Watercourse. A visible path through which surface water travels on a regular basis. Drainage areas which contain water only during and immediately after a rainstorm are not considered a watercourse. Wellpoint. A well used to measure groundwater levels. Wetland. An area(s) of marshes or swamps which have been designated as such by DEC or other agency having jurisdiction. Marshes or swamps that have not been classified by an agency as a wetland cannot be treated for design purposes as a wetland.
(d)Construction documents and permit requirements. It is unlawful to construct, replace or substantially alter an individual private on-site sewage disposal system without a permit issued by the department. Such system must meet the requirements of this section or 10 NYCRR Part 75 and Appendix 75-A. Exception: Applications for permits to construct and maintain private sewage disposal systems serving tax lots or zoning lots containing 15 or more dwelling units must be submitted to the New York City Department of Health and Mental Hygiene (DOHMH) unless such agency determines by reason of physical or engineering difficulties, estimated cost of construction or other pertinent considerations, that it is more practicable to construct individual systems, in accordance with 24 RCNY Health Code § 143.11.
(1)Connection to City sewer. No permit will be issued for an individual private on-site sewage disposal system where a public sanitary or combined sewer is available and connection thereto is feasible as determined by the New York City Department of Environmental Protection (DEP) in accordance with Section 107.11 of the New York City Building Code (BC) and PC Section 106.6.
(2)Field testing. No permit will be issued until the sand column meets the requirements of subdivision (g) of this section and an absorption test has been performed in accordance with subdivision (h) of this section.
(3)Applicant. All construction documents filed in connection with a permit application for a new, replacement of, or substantially altered individual private on-site sewage disposal system must be prepared by a registered design professional. Exception: Applicants for plumbing work consisting of in- kind repairs or replacements of "like-for-like" components may be licensed master plumbers.
(4)Construction documents.
(i)Lot diagram. A lot diagram must indicate all information as appropriate to the nature and extent of the work proposed including the size, height and location of proposed plumbing work; all existing structures on the zoning lot and their distances from lot and street lines; the established grade and existing curb elevations; and the proposed final grade elevations of the site shown by contours or spot grades at reasonable intervals. The lot diagram must be drawn using an accurate boundary survey to the city datum and must be attached to the application.
(ii)Application. An application for a permit must include all necessary forms and construction documents as required by the department. These include but are not limited to: (A) Two complete topographical surveys with original seal and signature by a licensed surveyor. (B) Three site plans, sealed and signed by a registered design professional, showing the following: lot dimensions, location of existing dwelling and proposed expansion, septic tank, seepage pit and drywell and proposed expansions, if any, their distance in relation to stream, lake, water course or DEC designated wetlands. (C) A fee as specified in 1 RCNY § 101-03. (D) Alteration plan showing existing building. (E) Computations showing existing hydraulic load on the existing septic system and the proposed hydraulic load as a result of the expansion. (F) Calculations showing the daily flow rate (Q). (G) Calculations showing the proposed tank capacity, in gallons.
(iii)Documents required from other agencies. Prior to construction document approval for an individual on-site private sewage disposal system, the applicant must submit applicable documents from other agencies having jurisdiction over such system, including: (A) DEP Certification of unavailability or nonfeasibility per PC Section 106.6.1.2. (B) A copy of the site connection proposal certified by the DEP Bureau of Water and Sewer Operations. (C) A DEC permit for systems located in freshwater wetlands, coastal wetlands and coastal zone erosion hazard areas per 28-104.9. (D) City Planning Commission. Certification for systems located within a special natural area district per New York City Zoning Resolution Article X, Chapter 5. (E) Board of Standards and Appeals. Waiver for the construction of systems located within the bed of a mapped street per NYS General City Law 35.
(e)Waivers. Where there is a practical difficulty in carrying out the provisions of this section, the Commissioner may issue a waiver where such waiver is consistent with the general purpose and intent of 10 NYCRR Part 75 and 75-A.
(f)On-site location limitations. All systems must meet the following requirements, as applicable.
(5)Minimum separation. The minimum permissible distance between the various components of the sewage system and between the components and various encumbrances must comply with Table 1. Exception: The separation distance between the outer perimeter of the aggregate collar of the seepage pit or the outer perimeter of the sand collar of the outermost edge of the sand filter field and the front property line adjacent to the street may be zero feet provided that one of the following conditions is met: (i) Ten feet of horizontal clearance to any water main in the street is maintained via a direct measurement; or (ii) A watertight pipe/sleeve is installed around the water main in the street if it is located within ten feet of an absorption facility; or (iii) The presence of at least two feet of relatively impermeable soil which has a percolation rate greater than 120 minutes/inch is verified as being located between the water main in the street and the seepage pit through performance of a percolation test in the on-site soil at the approximate depth of the water main in the street. Percolation test documentation must be submitted by the applicant for inclusion in the permit file when two feet of relatively impermeable on-site soil is used in lieu of ten feet of horizontal clearance or a water main protective sleeve. Table 1Minimum Distances Between Sewage System Components and Between Components and Encumbrances Building Foundation WallProperty LineSand Filter FieldSeepage PitDrywellWater Service LineWater Course/ WetlandSeptic Tank10 ft10 ft5 ft5 ft–––Sand Filter Field20 ft10 ft20 ft20 ft20 ft10 ft100 ftSeepage Pit20 ft10 ft20 ft20 ft20 ft10 ft100 ftDrywell10 ft5 ft20 ft20 ft––– (6) Minimum lot area and frontage. The minimum lot area and frontage requirements are 10,000 square feet and 100 feet respectively. Exception: The minimum lot area and frontage requirements do not apply to a tax lot for which title was recorded in the applicable county clerk's office prior to August 1, 1968 where recorded dimensions of such lots are less than 10,000 square feet and/or the frontage of which is less than 100 feet, provided that only one individual private on-site sewage disposal system is permitted on each such lot.
(g)Sand column construction. All sand columns required for individual private on-site sewage disposal systems must be constructed in accordance with this section and tested in accordance with subdivision (h) of this section. Sand column construction is subject to special inspection.
(h)Soil and groundwater testing. Soil and groundwater testing is subject to special inspection and must include a field investigation consisting of the following: (1) Field Testing. The following tests must be performed at the site of a proposed individual private on-site sewage disposal system: (i) Groundwater depth verification. Groundwater depth verification must be conducted on sand columns constructed at the site of a proposed subsurface disposal system in accordance with subdivision (g) of this section. The depth of the groundwater is determined by installing a wellpoint within the sand column at the time of sand column construction. Wellpoint construction must be in accordance with paragraph (2) of this subdivision. Groundwater verification must be conducted in accordance with paragraph (3) of this subdivision.
(iv)Additional check if water is found. If water is found in the wellpoint after 72 hours have elapsed and the water level is no higher than five feet below the impervious soil layer, or three feet below the impervious soil layer in tidal areas, as specified in subparagraph (ii) of paragraph (3) of this subdivision, the department representative must check again for the presence of water after a gallon of water is poured down the wellpoint. (A) If the department representative observes the complete exit of the gallon of water from the wellpoint within 30 minutes, then the sand column is considered a dry hole, and the site is acceptable for installation of a seepage pit system. (B) If the gallon of water does not exit the wellpoint within 30 minutes, the applicant must remove, examine, clean and reset the wellpoint in the sand column and perform the groundwater verification again in accordance with this subdivision.
(v)Unacceptable site. If water is found in the wellpoint, following resetting, a seepage pit system is not appropriate for the site.
(vi)Invalid sand column. If a reading cannot be taken for any reason, the sand column is invalid and cannot be used for further testing.
(6)AT/PT termination. The AT/PT must be terminated if any of the following conditions occur: (i) Water flow stops. If the water flow stops for any reason for 15 minutes in a test that has no sign of failure.
(7)AT/PT failure criteria. The AT/PT is deemed a failure if any of the following conditions occurs: (i) Average rate. If the average rate for any given hour falls below 1.5 GPM while maintaining a steady water puddle on the top of the hole during the four-hour test.
1.If a hydrostatic test is used, it must be run for 28 hours. A tank that shows no water loss during such time period is watertight.
2.If a vacuum test is used, it must apply five inches of mercury vacuum for ten minutes. A concrete tank that demonstrates no detectable vacuum loss during such time period is watertight. (F) The walls and floor of a cast-in-place concrete tank must be poured at the same time (monolithic pour). Figure 2Typical Concrete Septic Tank (vi) Fiberglass and polyethylene tanks. In addition to meeting the requirements of subparagraph (i) of paragraph (2) of this subdivision fiberglass and polyethylene tanks must comply with the following: (A) A fiberglass or polyethylene tank must not be installed in areas where the groundwater level can rise to the level of the bottom of the septic tank. (B) The manufacturer's installation instructions must be followed during installation, bedding, and backfilling of a fiberglass or polyethylene septic tank so as to prevent damage to tank walls and bottom. (C) A fiberglass or polyethylene tank must be delivered to the site completely assembled. (D) All pipe penetrations and access ports must be sealed so that the tank is watertight. A hydrostatic air pressure or vacuum test must be performed to confirm watertightness. This test must be performed under the supervision of a special inspector.
(vii)Metal septic tanks. In addition to meeting the requirements of subparagraph (i) of paragraph (2) of this subdivision metal septic tanks must be designed as follows: (A) Metal tanks must be labeled indicating conformance with UL 70. (B) Any damage to the interior or exterior tank coating must be refinished with an equivalent coating of material prior to placement or backfill. (C) Metal tanks must have a minimum diameter of five feet. The length must be at least two but not more than four times the diameter. (D) See Figure 3 for typical metal tanks. Figure 3Typical Metal Septic Tank (3) Associated system components.
(viii)Driveways and paved areas. Driveways and paved areas may not be located above absorption facilities including subsurface sand filters unless the requirements listed below are met: (A) Lateral vent piping must be installed between each distribution lateral. A minimum spacing of 18 inches must be provided between vent piping and distribution laterals. Lateral vent pipe must be four-inch SDR 35 perforated PVC or equally acceptable material. (B) The lateral vent pipes must connect to a vent pipe. The vent pipe must be a minimum of four inches in diameter and must not be connected to the house vent stack. (C) See Figure 6 for typical sand filter field beneath paved areas. Figure 6Typical Sand Filter Field (Beneath Paved Areas) (ix) Serpentine rock. Sand filter fields are required whenever serpentine rock is proposed as the medium for the ultimate disposal of the effluent. Sand columns must be dry with a minimum of four feet of filter sand above serpentine rock. Sand filter field system over serpentine rock must be designed and installed in accordance with the following requirements: (A) The system design must include at least six feet of vertical separation between finished grade and the serpentine rock. (B) Sand filter fields located above dry sand columns at locations where serpentine rock is less than six feet below finished grade must be modified to provide a minimum of four feet of sand filter both horizontally and vertically from distributor aggregate to serpentine rock.
(8)Expansion of existing septic systems. Where an alteration is proposed that will result in an increase in the number of bedrooms in one- and two-family properties or the daily flow rate (Q) in all other properties, thereby increasing the load on that system, the requirements of this paragraph apply. Exception. Cesspools may not be expanded. Cesspools must be replaced with an acceptable system in accordance with the requirements of this section.
(j)Abandoned septic systems. The following requirements apply: (1) Abandoned existing septic systems. An individual private on-site sewage disposal system must be abandoned and a connection made to a newly constructed sanitary or combined sewer when such sewer fronts the subject property. Connection must be made within six months of the sewer being placed into service.
(k)Maintenance and operation. The following requirements apply: (1) Maintenance. The owner must maintain the septic system in good working order and must have the septic system inspected and pumped as needed.
(l)Plot plans. Where a new individual private on-site sewage disposal system is installed the applicant of record must prepare a plot plan. The plot plan must contain the location of all pertinent components comprising the individual private on-site sewage disposal system and maintenance and inspection schedule. Where a drywell is installed it must be indicated on the plot plan. The plot plan must be permanently affixed to the inside wall adjacent to the fresh air outlet pipe.
(m)Restrictive declaration. Where a new individual private onsite sewage disposal system is installed the owner must file a restrictive declaration noting the existence and maintenance requirements of an individual on-site private sewage system on the property with the City Register or County Clerk, and the page number and liber number must be identified in the permit application and on the temporary and permanent certificate of occupancy. Where an individual private on-site sewage disposal system is abandoned pursuant to paragraph (1) of subdivision (j) the restrictive declaration must be terminated in accordance with the department's procedures.
(n)Special Inspections. Special inspections are required for the installation of individual private on-site sewage disposal systems in accordance with Table 7. Table 7Special Inspection CATEGORYTOPICSECTIONSand column constructionMinimum depth of sand columnSerpentine rockBackfilling the excavation1 RCNY § 8001-01(g)(2)1 RCNY § 8001-01(g)(4)1 RCNY § 8001-01(g)(5)Soil and groundwater testingAbsorption test/percolation test (AT/PT)Groundwater verificationNumber of AT/PT for seepage pit and sand field systemsAT/PT on sand column backfill materialAcceptance criteria for absorption testsAT/PT termination1 RCNY § 8001-01(h)(1)(iii)1 RCNY § 8001-01(h)(3)1 RCNY § 8001-01(h)(4)1 RCNY § 8001-01(h)(5)(i)1 RCNY § 8001-01(h)(5)(iii)(B)1 RCNY § 8001-01(h)(6)Design and construction standards for all types of systemsSeptic tanks, Concrete tanksSeptic tanks, Fiberglass and polyethylene tanksEvaluation of existing system Infiltration testing of existing individual private on-site sewage disposal systems1 RCNY § 8001-01(i)(2)(v)(E)1 RCNY § 8001-01(i)(2)(vi)(D)1 RCNY § 8001-01(i)(8)(i)1 RCNY § 8001-01(i)(8)(iii)Maintenance and operationDye tests or other diagnostic measures to verify the condition of the system1 RCNY § 8001-01(k)(6) (o) Referenced standards. These standards are adopted in full, except to the extent there is a conflict with this section, in which case the provisions of this section will apply. StandardNameYearAmerican Standard Test Method (ASTM) Standards:C 33Specifications for concrete aggregates2003D 448Standard classification for sizes of aggregate for road and bridge construction2003aD 1586Specifications for penetration test and split-barrel sampling of soils1999Underwriters Laboratories (UL) Standard70Standard for septic tanks, bituminous coated metal2001 (Added City Record 9/18/2017, eff. 10/18/2017; amended City Record 12/27/2018, eff. 1/26/2019)
