An MTD is required to be NJCAT verified and NJDEP certified when the MTD is used to satisfy the requirements of the Stormwater Management rule (N.J.A.C. 7:8), as a result of triggering the requirements for major development.

For projects receiving New Jersey Environmental Infrastructure Financing Program (NJEIFP) funding, an MTD must be either: 1) NJCAT verified and NJDEP certified or 2) installed using the NJEIFP MTD Funding Policy.

An MTD which is not NJCAT verified or NJDEP certified may be used as long as the MTD is not intended to satisfy the requirements of the Stormwater Management rule and is not subject to NJEIFP MTD Funding Policy.

Please note that any MTD installed should be listed on the MS4 permittee’s inventory of stormwater management measures and must be properly maintained by the responsible party. Other state, federal and local requirements may apply.

Green Infrastructure Guidance for MTDs (April 23, 2020)

For an MTD to be considered “green infrastructure” in accordance with the March 2, 2020 amendments to the Stormwater Management rules at N.J.A.C. 7:8, the MTD must meet the GI definition noted at amended N.J.A.C. 7:8-1.2. Specifically, the MTD shall (1) infiltrate into the subsoil; and/or (2) treat stormwater runoff through filtration by vegetation or soil.

An MTD that uses a bio-filtration media and can be configured "above ground" and incorporate a tree box, planter box, or shrubs, etc., would meet the GI definition. Any MTD with bio-filtration media that would be placed "below ground" as a vault without any vegetation can be considered GI (for NJ purposes) only if the device infiltrates stormwater into the subsoil. Further, the below ground device (vault) would need to meet the NJDEP BMP Manual conditions (see Appendix E) of having the soil below the MTD meet the minimum tested infiltration rate of one inch per hour, have at least two feet of separation from the seasonal high water table, and infiltrate into the subsoil.

The table below includes the listing of MTDs that are NJCAT verified and NJDEP certified under the updated procedures and protocols dated January 25, 2013. For the NJCAT web page, click here.

The certifications below for HDS MTDs are valid only when the proposed configuration of an MTD, including all internal components, is the same as the tested configuration and the MTD is installed with the same inlet/outlet pipe angles tested. It should be further noted that multiple inlet pipes and/or grate configurations have not been verified or certified. Any deviation from the tested configuration, including the use of alternative inlet/outlet pipe angles, multiple inflow pipes, and/or grate inlets, will prevent the MTD from being awarded the certified TSS removal rate and may result in non-compliance with the Stormwater Runoff Quality Standard.

Green Infrastructure (GI) MTDs

MTDs NOT Considered GI