With regards to the risk of groundwater pollution, the New York State Department of Environmental Conservation (NYSDEC) has updated their Part 360 regulations governing solid waste facilities to include new Part 361 regulations for composting and mulching operations.


Reports released from the NYSDEC and Suffolk County Department of Health Services (SCDHS) indicated potential groundwater impacts related to mulching and composting activities.  In response, the NYSDEC developed a comprehensive study which focused on the operation of 80 organic waste management facilities on Long Island to further define the potential environmental impacts from mulching and composting operations. Potential environmental impacts may include fires, fugitive dust, odors and groundwater contamination, among others.

The study concluded that run-off from mulch can transport carbon to the ground, which can result in changes to the groundwater beneath it, such as higher concentrations of heavy metals including manganese.  Long term exposure to manganese can cause damage to the nervous system.

Regulatory requirements now include the development of groundwater protection plans for mulching and composting facilities. Permitted and registered facilities will have to detail their plans to control the run-on and run-off of stormwater which could carry pollutants into the environment.

Mulch Compost

Existing Part 361 regulations will be further revised by 2019 to include more groundwater protection requirements for these organic waste management sites. Some requirements include groundwater monitoring and the development of best management practice methods to prevent groundwater impacts from mulching and composting operations.  Some practices include reducing and limiting stormwater contact with organic material, installing buffers for stormwater run-off, methods to prevent puddling around piles and pile run-off infiltration into the ground, and a run-off monitoring program to track and document water concentrations.Mulch Compost

The goal of these new regulations is to ensure that the environment is not adversely impacted from organic waste management facilities, as well as to ensure that Long Island’s drinking water and communities are protected.  The emphasis on groundwater protection stems from Long Island relying on a sole-source aquifer system for drinking water.

Existing facilities must ensure that they are in compliance with their respective NYSDEC regulations.  The Part 361 regulations require non-exempt mulching and composting facilities to either submit an application for a registration by May 4th, 2018 or to apply for a permit by November 4th, 2018, based on the amount of organic materials stored and processed.

Need help with developing best management practices for your facility or have any questions on mulch permitting or registration? Contact one of Walden’s experts today at (516) 624-7200.