Tables: Manufactured Treatment Devices (Non-GI)¶
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1. Table 1¶
| N.J.A.C. 7:8 Stormwater Management Rules – Applicable Design and Performance Standards | ||
|---|---|---|
| Green Infrastructure | Not Allowed | |
| Stormwater Runoff Quantity | Not Allowed | |
| Groundwater Recharge | Not Allowed | |
| % | Stormwater Runoff Quality | Only with a waiver or variance from N.J.A.C. 7:8-5.3, 50 or 80% TSS, depending upon posted NJDEP certification |
Source context and notes
# 11.3 MANUFACTURED TREATMENT DEVICES (NON-GI) Manufactured Treatment Devices (MTDs) are proprietary stormwater treatment systems used to address the stormwater quality impacts of land development, and they rely upon a variety of mechanisms to remove pollutants from stormwater runoff. This chapter solely addresses those MTDs that do not meet the definition of green infrastructure at N.J.A.C. 7:8-1.2, and for which a waiver or variance from N.J.A.C. 7:8-5.3 is required. For MTDs that do meet the green infrastructure definition, see Chapter 9.5: Green Infrastructure Manufactured Treatment Devices. When selecting an MTD for a particular site, the peak flow rate of the Water Quality Design Storm, the contributory drainage area and the physical size limits of its installation area must be known in advance. An MTD must have a Department-issued certification letter in order to be accepted for use and be sized in accordance with its published verification report. Provided the required waiver or variance is granted and all of the design criteria in this chapter is followed, the total suspended solids (TSS) removal rate is either 50 or 80%, depending upon the individual certification of the device, which may be found at: https://dep.nj.gov/stormwater/stormwater-manufactured-treatment-devices/ | N.J.A.C. 7:8 Stormwater Management Rules – Applicable Design and Performance Standards | | | | --- | --- | --- | | | Green Infrastructure | Not Allowed | | | Stormwater Runoff Quantity | Not Allowed | | | Groundwater Recharge | Not Allowed | | % | Stormwater Runoff Quality | Only with a waiver or variance from N.J.A.C. 7:8-5.3, 50 or 80% TSS, depending upon posted NJDEP certification | # Introduction An MTD is a proprietary device used to treat stormwater runoff. There are two types of MTDs currently certified by the Department: hydrodynamic sedimentation (HDS) devices and filtration devices. - HDS devices are flow-through structures that remove pollutants by settling either by creating a swirling vortex, through the use of a baffle system or laminar plates or a combination of those mechanisms. - Filtration devices remove pollutants by passing stormwater runoff through filter media.2. Table 2¶
| Area = | 0.25 ac |
|---|---|
| Slope = | 5% |
| CN Value = | 98 (100% Impervious) |
| Projected 2-year storm rainfall depth | 3.84 inches |
| Hydraulically most distant point to the inlet of MTD | 110 ft |