New Jersey Administrative Code › Title 7 - ENVIRONMENTAL PROTECTION › Chapter 14A - NEW JERSEY POLLUTANT DISCHARGE ELIMINATION SYSTEM › Subchapter 23 - TECHNICAL REQUIREMENTS FOR TREATMENT WORKS APPROVAL APPLICATIONS › Section 7:14A-23.28 - Drying beds for residuals

Current through Register Vol. 56, No. 14, July 15, 2024
(a) The following
				table of requisite areas applies to domestic sewage, the sludge of which is
				digested by an anaerobic method. Based upon the physical and chemical
				characteristics of the residual (for example, domestic/industrial, solids
				concentration, and/or method of prior stabilization) appropriate adjustments
				can be made to the following table. Written justification for any adjustments
				or alternative designs shall be provided in the engineer's report. However,
				under most circumstances drying beds will not be approved for dewatering
				unstabilized sewage sludge unless appropriate provisions to control odors have
				been included.
Area in sq. ft./capita
Open
Glass
Type of Treatment
Beds
Covered
						  Beds
Primary
1.50
60 percent
Standard Rate Filter
1.75
of the
						  area
High Rate Filter
1.75
of open
Activated Sludge
2.00
beds
Chemical Precipitation
2.25
(b)
				The following are minimum requirements governing the design of drying beds and
				phragmites reed beds:
1. Not less than two
				beds or compartments shall be provided;
2. For conventional sand drying beds:
i. Gravel shall be at least 12 inches deep
				with the top at least six inches above underdrains. Gravel shall be graded from
				1/8 to one inch in effective diameter; and
ii. Depth of sand shall be at least six
				inches and shall consist of clean coarse sand.
3. All drying beds shall be provided with
				underdrains of bell and spigot vitrified clay tile pipe, porous tile,
				perforated pipe, or other suitable material or drainage. Lateral drains shall
				be at least four inches in diameter laid with open joints. An acceptable
				engineering fabric shall be provided around joints. Drains shall be spaced not
				more than eight feet apart on center and have a minimum slope of one
				percent.
4. The permeability of the
				bottom and side walls shall not be greater than 1 x 10[LESS THAN]-7[GREATER
				THAN] cm/sec and shall extend 15 to 18 inches above the sand surface. Walls
				shall be at least six inches above the surrounding ground elevation to prevent
				soil from washing on beds;
5. Means
				shall be provided to facilitate the removal of dried sludge from drying
				beds;
6. Influent piping shall
				provide for uniform distribution of residuals across the entire drying bed
				area. Splash slabs shall be provided.
7. Residual bed effluent shall be treated and
				suitable means shall be provided for the satisfactory management of the
				residual cake.
8. The capacity of
				the beds shall be sufficient to process the residuals generated to prevent any
				day to day accumulations.
9. Drying
				beds proposed to be utilized to satisfy stabilization requirements shall be
				designed to meet the requirements for pathogen reduction and vector attraction
				reduction in accordance with N.J.A.C. 7:14A-20. For Phragmites reed beds, a
				minimum capacity to allow three weeks between loadings to the same bed at the
				projected sludge production shall be provided. Additional capacity to allow for
				bed evacuation is recommended.