[EXTERNAL]: Updated Monitored Natural Attenuation Technical Guidance Document now available!

The NJDEP Contaminated Site Remediation & Redevelopment Program is pleased to announce the availability of the updated Monitored Natural Attenuation (MNA) Technical Guidance Document.

The Monitored Natural Attenuation (MNA) Technical Guidance committee has revised the document to include a new section entitled, "Non-Decreasing Levels of Ground Water Contamination." This section discusses situations where contaminant concentrations are observed to decrease over time to an asymptotic level that lies above the applicable remediation standard without evidence of a further declining trend, but can still be considered candidates for MNA. Other significant changes to the MNA Technical Guidance Document include clarifying that sampling used to support MNA should be collected following any active remediation, and that the primary line of evidence to support MNA should include both a reducing plume boundary and reducing contaminant concentration or mass, in most cases.

The updated MNA Guidance document and its change log are available in the Guidance Library: https://nj.gov/dep/srp/guidance/.

Information regarding training on the updated MNA Technical Guidance Document is forthcoming.

The New Jersey Department of Environmental Protection is dedicated to protecting New Jersey's environment and public health. The agency prioritizes addressing climate change, protecting New Jersey's water, revitalizing its communities and managing and promoting its natural and historic resources.

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