7.0 Peat Bio-Filter - Alternate Peat Based System Options
Alternate peat based system configurations consist of an aerobic or septic tank, followed by a peat filter and an absorption area as described in this listing. Septic tank installations must consist of either a two-compartment rectangular tank or two rectangular tanks in series and must be in conformance with Chapter 73, Section 73.31. Aerobic tanks must be in compliance with Chapter 73, Section 73.32. All peat systems must also include a Zabel A-300 solids retainer or equivalent on the preceding septic or aerobic tank.
A. General Requirements For All Peat Based Systems
1. System Requirements
a. All Ecoflo installations are required to have a minimum of 195 cubic feet of peat evenly distributed in the filter unit (nominally 31 inches deep). The SEO shall confirm the volume of peat prior to final approval of the system. Note: New compressed packaging for peat requires multiplication of the volume printed on the packaging by 1.75 (the compression ratio).
b. The Puraflo system is sized at one preassembled peat filter module per bedroom (each module contains approximately 60 cubic feet of peat media). The depth of peat in the Puraflo system is 30 inches. No compression ratio is specified because these are pre-engineered, preassembled filter units.
2. Distribution of effluent from the septic tank or aerobic tank to the peat filter may be by gravity flow or pressure distribution. If a pump is required to lift effluent to the peat filter, a timed dose is required.
3. The peat filter must be watertight and all outlets properly sealed against liquid and solid infiltration and exfiltration. Where a liner is used, the liner must be 20 mil thick, polyvinyl chloride or polyethylene sheeting placed on 2 inches of sand or a layer of 10 ounce porous textile material to prevent punctures and tears. The liner must be extended to the surface and any inlets or outlets at or below the water table or at or below the water level in the unit must have an anti-seep collar, bentonite clay plug or leak-proof boot sealed to the liner material.
4. Peat filters require maintenance, including the periodic replacement of peat. The company's warranty must be attached to the permit application, permit and purchase agreement. This warranty must clearly notify the property owner of the need to replace the peat within the life expectancy period established by the company and provide access for the annual inspection.
Systems Approved Under This Listing
B. Alternate Peat System Option 1
This option involves treatment of septic or aerobic effluent using a self-contained peat filter with final treatment and disposal using a standard regulatory on-lot system or an at-grade absorption area designed in accordance with the alternate at-grade system standards in Part 9 of this guidance, except that the soil profile must show that there is a minimum of 20 inches of suitable soil between the bottom of the proposed absorption area and the limiting zone (48 to 60 inches of suitable soil or sand/soil is not required). Where the percolation rate is in the range of 3 to 60 minutes per inch, inclusive, up to a 40 percent reduction in the size of the absorption area is allowed. However, where the percolation rate is in the range of 61 to 180 min/in, inclusive, no reduction in absorption area sizing is permitted.
1. Use of this system: This system may be approved either to serve new development or as a repair system.
2. The following conditions apply to Alternate Peat Filter System Option 1:
a. An SEO that has successfully completed the appropriate DEP sponsored continuing education course that included this specific technology may independently review the design and issue the permit for alternate system designs approved under this listing. All other system proposals under this listing must be submitted to the DEP regional office for review and comment.
b. Where an at-grade system is proposed, sufficient soil profiles and hand auger soil evaluations must be conducted to assure that a minimum of 20 inches of suitable soil is present under the entire area proposed for the at-grade absorption area.
c. Sizing reductions are not cumulative. No additional sizing reduction is allowed for use of either an aerobic tank or infiltration chambers.
d. For repairs, best technical guidance must be applied to maximize system sizing up to the square footage of a full sized system.
e. Where an at-grade system is proposed, the design of the at-grade system must meet the alternate system standards for at-grade systems, except that the soil profile must show that there is greater than or equal to 20 inches of suitable soil (instead of 48 to 60 inches).
f. The system must be designed to take full advantage of the slope to move effluent out from under the absorption area and down gradient with the long side of the bed parallel to contours.
g. Where the system is used to serve a new dwelling, the soil profile evaluations and percolation testing must document that there is sufficient area for installation of a full-sized absorption area (prior to the calculation of the 40 percent reduction).
C. Alternate Peat System Option 2
A self-contained peat filter may be used in place of an intermittent sand filter (Chapter 73, Section 73.162) for individual residential spray irrigation systems permitted by the local agency. An SEO that has successfully completed the appropriate DEP sponsored continuing education course that included this specific technology may independently review the design and issue a permit for this alternate spray irrigation system. All others must submit designs to the DEP regional office for review and comment.
D. Alternate Peat System Option 3
A self-contained peat filter may be used in place of the required minimum depth of 12 inches of sand in a subsurface sand filter bed or trench where all other requirements of Chapter 73, Section 73.54 have been met. No reduction in absorption area sizing is allowed. An SEO that has successfully completed the appropriate DEP-sponsored continuing education course that included this specific technology may independently review the design and issue a permit for this alternate peat system. All others must submit designs to the DEP regional office for review and comment.
We are in the process of setting up Face-to-Face Courses. They will be posted here at our New Training Portal - Training Professionals Online Training Courses. We will be scheduling courses in soil science, soil morphology, hydric soils, and water sampling.