Md. Code Regs. 26.04.11.08

Current through Register Vol. 51, No. 22, November 1, 2024

Section 26.04.11.08 - Composting Facility Siting and Design Requirements

A. This regulation applies to composting facilities that are required to obtain a Composting Facility Permit under this chapter, and establishes conditions that the composting facility operator shall meet with respect to construction of the composting facility.

B. Siting Criteria.

(1) Except where a greater setback is required by local, State, or federal law or regulations, feedstock receipt, feedstock storage, active composting, curing, and compost storage areas of a composting facility may not be located closer than:

(a) 50 feet to the property line of a property not owned or controlled by the operator of the composting facility;

(b) 300 feet to a dwelling not owned or operated by the operator of the composting facility;

(c) 100 feet to a domestic well; and

(d) 100 feet to a stream, lake, or other body of water except an impoundment for use in the composting process.

(2) A composting facility shall be located in accordance with all applicable federal laws, regulations, or guidance related to the location of composting facilities at or near airports.

(3) A composting facility may not be located in a flood plain, except as otherwise approved by the Department.

(4) A composting facility shall be located and constructed in accordance with COMAR 26.23 and COMAR 26.24, relating to nontidal and tidal wetlands, respectively.

(5) A composting facility may not be located in conflict with the Chesapeake Bay Critical Area Commission Criteria under COMAR 27.01 or any locally adopted Critical Area Plan.

C. Basic Design Criteria.

(1) As required by Regulation .09 of this chapter, the CFOP shall clearly define:

(a) The locations at the composting facility to be used for feedstock receiving and storage, active composting, curing, and compost storage; and

(b) The maximum throughput and capacity of the composting facility.

(2) No material shall be stored in excess of the capacity specified in the CFOP.

(3) The composting facility shall be of sufficient size to allow processing of materials as necessary to avoid nuisance conditions and shall have adequate space for material stockpiles, windrows, or piles of manageable dimensions for maintaining aerobic conditions, curing piles, staging of finished compost, and equipment.

(4) The maximum windrow or pile size and minimum windrow or pile spacing shall match the capability and requirements of the equipment used at the composting facility.

(5) Access to the composting facility shall be limited to authorized entrances, which shall be secured from public access when the composting facility is not in operation.

(6) The composting facility shall have a sign at its entrance that lists:

(a) The name and address of the composting facility;

(b) Days and hours of operation; and

(c) Emergency contact information.

(7) The composting facility shall have all-weather access roads.

(8) Structures such as berms or ditches shall be used to prevent run-on to the feedstock receiving, feedstock storage, active composting, curing, and compost storage areas.

D. Distance to Groundwater.

(1) The composting facility shall be constructed and located to comply with the following minimum vertical distances between the seasonal high water table and any surfaces used for feedstock receiving, feedstock storage, active composting, curing, or compost storage:

(a) For a composting facility located outside the coastal plain province, as shown in COMAR 26.04.02.13, the minimum distance shall be 4 feet; and

(b) For a composting facility located within the coastal plain province, as shown in COMAR 26.04.02.13, the minimum distance shall be as follows:

(i) For a composting facility located in an area with an applicable groundwater protection report approved by the county health department under COMAR 26.04.02.04, the minimum distance shall be the distance specified in the report as the minimum soil treatment zone for an on-site sewage disposal system;

(ii) For a composting facility located in an area where no approved groundwater protection report applies, the minimum distance shall be 4 feet;

(iii) For a composting facility that will operate under the general Composting Facility Permit, the minimum distance shall be the distance specified in the general permit;

(iv) The Department may set another distance if necessary to adequately protect groundwater, as determined by the Department and based on factors such as whether the composting facility is located in a wellhead protection area, the permeability of the buffer zone between the surface and groundwater, the proportion of rock in the buffer zone, whether the composting facility is located near a sole source aquifer, and any other relevant hydrogeologic factors; and

(v) Notwithstanding §D(1)(b)(i)-(iv) of this regulation, the minimum distance shall in no case be less than 2 feet.

(2) The Department may specify the method to be used for determining the distance to the seasonal high water table.

(3) The Department may exempt an indoor composting facility from the requirement for distance to the seasonal high water table in §D(1) of this regulation.

E. Pad Requirements.

(1) Slope of surfaces. All surfaces used for feedstock receiving, feedstock storage, active composting, curing, and compost storage shall be sloped between 1 and 6 percent, as determined by site conditions and as sufficient to prevent ponding, except for areas located indoors, which shall have slope sufficient to prevent ponding and facilitate cleaning.

(2) Pad Requirements for Tier 1 Facilities. For Tier 1 Facilities, the surfaces used for feedstock receiving, feedstock storage, active composting, curing, and compost storage shall be composed of an all-weather pad.

(3) Pad Requirements for Tier 2 Small Facilities.

(a) For Tier 2 Small Facilities, the surfaces used for feedstock receiving, feedstock storage, curing, and compost storage shall be composed of an all-weather pad.

(b) Surfaces used for active composting shall be composed of:

(i) An all-weather pad with a 6-inch layer of carbon-rich substrate such as wood chips placed beneath each active composting pile or windrow, above the all-weather pad; or

(ii) A low-permeability pad constructed in accordance with the requirements for Tier 2 Large Facilities in §E(4)(b) of this regulation, if the requirements for management of contact water in §F(2) or F(3) of this regulation are also met.

(c) The 6-inch layer of carbon-rich substrate required under §E(3)(b)(i) of this regulation shall be placed under an active composting pile or windrow at the time it is initially formed, but the layer is not required to be replaced each time the pile is turned or consolidated.

(4) Pad Requirements for Tier 2 Large Facilities.

(a) For Tier 2 Large Facilities, surfaces used for curing and compost storage shall be composed of an all-weather pad.

(b) Surfaces used for feedstock receipt, feedstock storage, and active composting shall be constructed of a low-permeability pad that meets the following requirements:

(i) A pad constructed on the surface of the ground shall have a hydraulic conductivity of 1 x 10^-5 cm/sec or less;

(ii) A pad that is buried shall have a hydraulic conductivity of 1 x 10^-6 cm/sec or less;

(iii) A pad made of asphalt concrete or Portland cement concrete shall be designed to minimize the potential for cracking and allow equipment to operate without damage; and

(iv) A pad made of compacted clay shall have a minimum thickness of 1 foot and shall be protected from desiccation and installed in a manner such that the integrity of the pad will not be impaired by the operation of heavy equipment used on the pad.

(c) For Tier 2 Large Facilities in which the active composting piles are covered, the active composting area required to have a low-permeability pad under §E(4)(b) of this regulation is limited to the area directly underneath each covered pile and does not include the aisles between the covered piles.

F. Design Requirements for Management of Stormwater and Contact Water.

(1) The composting facility shall be designed to manage any stormwater discharges associated with industrial activity, as defined in 40 CFR § 122.26(b)(14), in accordance with:

(a) The NPDES permit issued by the Department;

(b) State and local stormwater requirements; and

(c) State and local erosion and sediment control requirements.

(2) Uncovered Tier 2 Large Facilities.

(a) This subsection applies to Tier 2 Large Facilities in which the active composting piles are not covered.

(b) The feedstock receiving, feedstock storage, and active composting areas shall direct contact water to a collection basin, tank, or other containment system before:

(i) Reuse on feedstock storage or active composting piles in accordance with the CFOP and in a manner that prevents contamination of materials that have met the pathogen reduction requirements in Regulation .09B(10) of this chapter;

(ii) Transport off site for treatment at a permitted facility; or

(iii) Discharge under COMAR 26.08.01-.04.

(c) The collection basin, tank, or other containment system used to collect contact water shall:

(i) Be sized to handle at least a 24-hour, 25-year storm event;

(ii) For a basin, have a synthetic or compacted clay liner with a hydraulic conductivity of 1 x 10^-7 cm/sec or less;

(iii) For a liner constructed of compacted clay, have a thickness of at least 1 foot; and

(iv) For a tank or other containment system, be constructed of impermeable material.

(3) Covered Tier 2 Large Facilities.

(a) This subsection applies to Tier 2 Large Facilities in which active composting piles are covered.

(b) The following are considered contact water at Covered Tier 2 Large Facilities and shall be collected and contained in accordance with the requirements of §F(3)(d) of this regulation:

(i) Liquid that drains from the bottom of a covered pile; and

(ii) Runoff from any uncovered feedstock receipt or feedstock storage areas.

(c) The following are not considered contact water at Covered Tier 2 Large Facilities and are not subject to the collection and containment requirements of §F(3)(d) of this regulation:

(i) Runoff from active composting areas that has contacted only covered piles, roofs, or empty aisles; and

(ii) Runoff from any feedstock receipt and feedstock storage areas covered by a roof, if the runoff has contacted only the roof or empty aisles.

(d) Contact water from Covered Tier 2 Large Facilities shall be collected and contained in a collection basin, tank, or other containment system before:

(ii) Transport off site for treatment at a permitted facility; or

(iii) Discharge under to COMAR 26.08.01-.04.

(e) A collection basin, tank, or other containment system used to collect contact water shall:

(i) Be sized to contain all contact water generated by the composting facility;

(ii) For a basin, have a synthetic or compacted clay liner with a hydraulic conductivity of 1 x 10^-7 cm/sec or less;

(iii) For a liner constructed of compacted clay, have a thickness of at least 1 foot; and

(iv) For a tank or other containment system, be constructed of impermeable material.

G. Monitoring Wells. The Department may require a composting facility to install monitoring wells and conduct groundwater monitoring if:

(1) The composting facility is located in karst terrain;

(2) The composting facility is located in a wellhead protection area; or

(3) The Department otherwise considers monitoring necessary to adequately protect groundwater because of the particular characteristics of the site.

Md. Code Regs. 26.04.11.08

Regulation .08 adopted effective 42:12 Md. R. 763, eff.7/1/2015