If construction associated with a single family dwelling requires a planning and/or zoning approval and disturbs one or more acres, the proposed project is subject to the Residential Site Improvement Standards (RSIS) and the requirements of the Stormwater Management rules. Please note that a zoning permit, which may be required as part of a building permit, is considered a zoning approval under the MLUL. Furthermore, if a new single family dwelling needs a permit from the Division of Land Use Regulation (DLUR) and meets the definition of “major development”, it is subject to stormwater review by the Department regardless of the extent of municipal jurisdiction, unless otherwise exempt.

No. A single-family dwelling on an existing single-family lot would not be subject to the requirements of these rules unless a new “major development” is proposed on the lot. In other words, if the proposed development involves less than one acre of disturbance, involves less than one quarter-acre of new impervious surface and is not part of a larger development, then the project is not regulated. . However, a project on a single-family lot with a single-family dwelling that constitutes “major development” must comply with these rules except for those exempted at N.J.A.C. 7:8-1.6.

An individual homeowner cannot be listed as the responsible party, but can have responsibilities in the maintenance of specific BMPs. For example, a homeowner’s association may be the responsible party for specific BMPs, but under an agreement, the homeowner is required to mow or perform other maintenance activities. However, the homeowner’s association is the responsible party to ensure that maintenance is occurring in an appropriate manner.

For phased projects, only the portion of the project that has obtained the necessary qualifying local and Department approvals prior to February 2, 2004 is exempt or grandfathered. All new elements of a phased project that do not have approvals prior to February 2, 2004 must comply with the Stormwater rules. For example, if a developer owned a 50-acre lot and had a qualifying Department permit for a phased project on 25 of those acres, the remaining 25 acre portion of that lot without Department permits would not be grandfathered.

Projects (or portions of projects) that are exempt from these rules under the grandfathering provision are still subject to the stormwater management requirements that were in effect upon their approval.

Yes. The rules contain a grandfathering provision at N.J.A.C. 7:8-1.6. The following approvals must have been issued prior to February 2, 2004 in order for a major development to be exempt from these rules.

1. One of the following Municipal Land Use Law approvals:
   1. Preliminary or final site plan approval;
   2. Final municipal building or construction permit; or
   3. Minor, preliminary or final subdivision approval where no subsequent site plan approval is required; and, if required
2. One of the Department permits approved under the following statutes, provided that the permit included a stormwater management review:
   1. Flood Hazard Area Control Act, N.J.S.A. 58:16A-50 et seq.;
   2. Freshwater Wetlands Protection Act, N.J.S.A. 13:9B-1 et seq.;
   3. Coastal Area Facilities Review Act, N.J.S.A. 13:19-1 et seq.;
   4. Waterfront Development and Harbor Facilities Act, N.J.S.A. 12:5-3.

If a project has a municipal approval that requires no subsequent site plan approval and still requires one of the Department permits listed above, and has not secured any of those approvals, the rules will apply if that permit review triggers the stormwater rule (one acre of disturbance or 0.25 acres of new impervious). If none of the Department permits listed above is required, then the project is exempt from the requirements of the new rules.

N.J.A.C. 7:8-1.6 specifically states that in order to be exempt from the Stormwater Management rules, the property must have received approval pursuant to the MLUL and require no subsequent site plan approval. Therefore, if the subdivision precedes the enactment of the MLUL, then this exemption does not apply.

Government projects that are not subject to the MLUL, but require Department permits or approval, are also exempt if they have obtained one of the qualifying Department permits identified above prior to February 2, 2004. This applies to government projects, such as schools or municipal buildings that are defined as “major development” and are undertaken by a government agency. Please note that under the municipal NJPDES permit these projects still may be required to meet the provisions of the stormwater rule.

The duration of the exemption is determined by effective life of the approval(s), which qualified the project for exemption. When the qualifying Department approval or local approval expires, the exemption also expires.

The Department must determine if any revision to a qualifying permit or approval would have a de minimis impact on water resources in order for the exemption to remain valid. This is necessary to ensure that changes to preliminary local approvals will not result in an adverse impact to water resources that would otherwise be prevented under these rules. N.J.A.C. 7:8-1.6(e) establishes the criteria to be considered by the Department in determining de minimis impact. If the Department determines that the impact is not de minimis, then the exemption is void and the “major development” is subject to the requirements of the rules.

The Stormwater Management rules only apply if the applicant needs to resubmit to the Department or the local government for some change in design or to obtain additional permits that might be needed. If all necessary approvals have already been received, the applicant need not redesign the project to meet the Stormwater Management rules and the project can be constructed as originally approved.

No. Stormwater runoff from agricultural development meeting the definition of “major development” must meet the performance standards established in these rules. Development on agricultural land means: any activity that requires a State permit; any activity reviewed by the County Agricultural Boards (CAB) and the State Agricultural Development Committee (SADC), and municipal review of any activity not exempted by the Right to Farm Act, N.J.S.A. 4:1C-1 et seq. This does not conflict with the Right to Farm Act, which recognizes the State’s continuing authority to regulate agricultural development at N.J.S.A. 4:1C-9.

The project is not grandfathered because the DLUR permit did not include a stormwater review component.

No. These approvals were not listed as qualifying approvals for exemptions under N.J.A.C. 7:8-1.6(b)1.

NJDEP and NJDA programs both regulate stormwater runoff but for different purposes and design compliance utilizes different BMPs.  Compliance with one or the other agency does not automatically constitute compliance with the other.

The rules apply if there is proposed activity on the site that meets the definition of “major development”.

Redevelopment, defined for the purposes of this question, is a new impervious surface that replaces an equal area of existing impervious surface on a project site. For redevelopment of existing impervious surfaces, the required TSS removal rate is the greater of the TSS removal rate of the existing stormwater treatment system, or 50% TSS is required. For new impervious surfaces an 80% TSS removal rate applies. However, the water quality provisions of the Stormwater Management rules only apply if the impervious surface onsite increases by at least 0.25 of an acre (See Questions 4.3 through 4.6 below for examples). Please note that proposed new discharges within the 300-foot riparian zone established under the Flood Hazard Area Control Act Rules at N.J.A.C. 7:13-4.1(c)1 must obtain an individual permit under N.J.A.C. 7:13-11.2(j), in which the post-construction load of total suspended solids of new discharge must be reduced by 95 percent of the anticipated load from the developed site, expressed as an annual average, regardless of whether or not the site is redeveloped.

The Stormwater Management rules apply since there is 4 acres of proposed disturbance. However, the water quality provisions only apply if there is 0.25 of an acre of “new” impervious surface. If there is no reduction in water quality from the runoff, no additional water quality measures are required, provided that the existing pavement is removed, the surface is scarified 6” to 12” where there has been soil compaction and the area is restored to a natural vegetated condition in accordance with the “Standards for Soil Erosion and Sediment Control in New Jersey, Standard for Permanent Vegetative Cover for Soil Stabilization.”

Milling and/or repaving do not count as disturbance or redevelopment and do not trigger the Stormwater Management rules, provided there are no changes to the existing stormwater drainage system. The reconstruction of these areas, however, does constitute disturbance and is discussed below.

Since more than 1 acre of land will be disturbed, the project is a “major development” and must therefore meet all standards of the Stormwater Management rules. An 80% TSS removal rate would apply to the new acre of pavement. For the existing 3 acres of pavement, if water quality is provided under existing conditions, the required TSS removal rate is the greater of the TSS removal rate of the existing stormwater treatment system, or 50% TSS. Runoff from rooftops does not need to be treated for TSS removal but should be deed restricted so that future development of the rooftop address the 80% TSS requirement.

Under N.J.A.C. 7:8-5.5(a), water quality control is only required if an additional 0.25 of an acre of impervious surface is proposed. Since there is a net decrease in impervious surface in this case, the water quality standards would not apply to this project unless more than 0.25 acres of impervious surface is proposed.

Previously developed areas are those portions of a site covered by paved, gravel or dirt driveways, streets, roads and parking areas, gravel, pavement, buildings, impervious surfaces, lawns or structures. Areas that simply have been (or have once been) cleared of vegetation are not considered “previously developed” if woody vegetation has been reestablished. Only those portions of a site that have been previously developed are exempt from the groundwater recharge requirements.

If a portion of a site contains karst geology, the Department encourages the placement of any stormwater recharge facility outside of the karst areas. The groundwater recharge requirement is mandatory for all sites (with the exception of areas with high pollutant loading or runoff from source material). Project redesign to incorporate dispersed runoff instead of a structure for recharge or a reduction in scope may be necessary to ensure compliance with the rules in this area.

Some sites have very high groundwater tables and recharging water might exacerbate flooding onsite. The rules do not provide an exemption for groundwater recharge in tidal areas. It is unlikely that maintaining the existing level of groundwater recharge on a site would exacerbate flooding. Furthermore, in tidal areas there may be concern about saltwater intrusion as a result of the loss of groundwater recharge. Nevertheless, if meeting the groundwater recharge standards would create an adverse condition, the rules prohibit recharge. In addition, flexibility can be provided on a site-by-site basis through a Freshwater Wetlands Individual permit or through the Hardship exception provisions in the other DLUR permit programs. However, the applicant must demonstrate that groundwater recharge is not necessary to maintain baseflow to the aquifer as part of the application.

No. Water quality treatment must be provided outside these regulated areas.

The use of grassed swales and umbrella roadway drainage assists in addressing the requirements for nonstructural stormwater management strategies, which is mandatory for every project. If a stormwater BMP such as a grassed swale is not identified in N.J.A.C. 7:8-5.5(c), the design engineer has the option to provide documentation regarding the specific BMP. Alternative stormwater management measures, removal rates and methods of calculating removal rates may be used if the design engineer provides documentation demonstrating the capability of these alternative rates and methods to the review agency.

The Stormwater Management rules at N.J.A.C. 7:8-5.5(c) allow the use of multiple BMPs in series to provide water quality treatment. Since different BMPs utilize different mechanisms to remove suspended solids, combining different BMPs in series will generally provide better water quality treatment than using the same BMP more than once. For this reason, the Department discourages the use of the same kind of BMP in series.

It depends on the condition of the ditch being replaced. If the existing ditch is generally devoid of vegetation, due to persistent erosion or previous lawful lining or armoring, the ditch does not currently provide any significant water quality treatment. Replacing such a ditch with a stormwater system would likely not degrade the quality of the runoff from the roadway. Therefore, the area draining to the ditch would not be considered as new impervious area under the definition of major development and for the water quality requirements of the rule.

However, if the ditch is stable and contains vegetation, a certain level of water quality treatment is provided to the roadway runoff. In this case, the inflow area would be considered an additional impervious area and runoff from the roadway must be treated. In addition, if existing culverts along the ditch create significant impoundments for the water quality design storm, a level of water quality treatment is provided, and the applicant must provide treatment equivalent to the existing TSS removal rate or 50% TSS removal, whichever is greater. Furthermore, if the capacity of the existing stormwater conveyance is increased by the new storm sewer system, and either the 0.25-acre impervious threshold or the 1-acre disturbance threshold is exceeded, the runoff quantity standards at N.J.A.C. 7:8-5.4(a)3 would apply.

Clean roof runoff and runoff from lawns, walkways, patios or decks do not have to be treated for TSS removal. However, these projects must be restricted so that any future change in land use will not result in increased pollutant loads from these impervious areas. If such changes should occur, the applicant must provide the water quality treatment required for that new use.

However, nutrients are required to be reduced to the maximum extent feasible. For example, in areas where birds tend to congregate on rooftops and contribute to the nutrient loads, measures to manage birds and prevent additional nutrient loads should be addressed. For lawn areas, measures to prevent additional nutrient loads into waters, such as changes in the type and application of fertilizer, pet waste stations and goose management measures should also be addressed.

Discharge of clean roof runoff into a system that provides infiltration is considered a drywell discharge, which does not require pre-treatment. Note that certain types of discharges, such as an industrial development that would have an air discharge or other situations where contaminants could deposit on the roof, cannot be discharged to a drywell. Additional details are included in Chapter 9.4 of New Jersey’s Stormwater BMP Manual.

No. A certification is a letter issued by the Department with associated removal rates and conditions. Devices that are used to address TSS removal must have a certification letter. Devices are not required to be field-tested before being used to address the TSS requirements, unless the certification letter includes that specific condition. However, it should be noted that in cases of hardship, NJDEP could allow the use of MTDs that have not received the Department certification, only if the applicant demonstrates that both generic BMPs and certified MTDs cannot be utilized for the project in accordance with N.J.A.C. 7:8-5.7(b).

No. However, if other proposed revisions to the site result in a reduction of the existing water quality being provided for the site, or result in an increase in peak flows and/or volume of runoff, then the requirements of the Stormwater Rules may apply. Please refer to Redevelopment Section  for more information.

Effective on June 20, 2016, the Flood Hazard Area Control Act Rules at N.J.A.C. 7:13-4.1(c)1 establish 300-foot riparian zones along Category One waters, as designated in the Surface Water Quality Standards at N.J.A.C. 7:9B, and certain upstream tributaries to Category One waters. A person shall not undertake a major development that is located within or discharges into a 300-foot riparian zone without prior authorization from the Department under the Flood Hazard Area Control Act Rules, N.J.A.C. 7:13. The Special Water Resource Protection Area (SWRPA) defined and regulated under the prior Stormwater Management rules at N.J.A.C. 7:8-5.5(h) will be now addressed and regulated under the Flood Hazard Area Control Act Rules. Therefore, the term “Special Water Resource Protection Area” has been removed from the Stormwater Management rules, N.J.A.C. 7:8. See www.nj.gov/dep/landuse for information on the FHACA rules. Please contact Division of Land Use Regulation with any specific questions regarding riparian zones.

Yes, the Flood Hazard Area Control Act Rules at N.J.A.C. 7:13-4.1(c)1 establish 300-foot riparian zones along Category One waters, as designated in the Surface Water Quality Standards at N.J.A.C. 7:9B, and certain upstream tributaries to Category One waters. A person shall not undertake a major development that is located within or discharges into a 300-foot riparian zone without prior authorization from the Department under N.J.A.C. 7:13. For more information, please visit the Division of Land Use Regulation’s website at https://www.nj.gov/dep/landuse.

The Stormwater Management rules do not require a buffer for waters, but other rules may. For example, the Flood Hazard Area Control Act Rules, the Rules on Coastal Zone Management and the Pinelands Comprehensive Management Plan, to name a few, all require buffers on Category One waters and other waters. In addition, some municipalities may require buffers along or near certain waterbodies. Please refer to Section 11.0,.Division of Land Use Regulation Review and Section12.0, Stormwater Review by Municipalities for more information.

Yes, but only if the requirement in the Stormwater Management rules at N.J.A.C. 7:8-5.3 for the maximization of nonstructural stormwater management strategies have first been met. Note that the Stormwater BMP manual states that the use of an infiltration basin is only recommended for the depths of two feet or less.

A bioretention basin has a maximum depth of 12 inches for the stormwater quality design storm. A bioretention swale has a maximum depth of 18 inches, since the slope and the linear nature of the swale will result in low depths of ponding in portions of the basin. However, the average depth of ponding in the basin should be no greater than 12 inches.

Any applicant has the option to submit an alternative BMP design to the review agency, with sufficient documentation to demonstrate the appropriate removal rates. If the project is the subject of a Division of Land Use Regulation permit, the use of a BMP that is not listed in the BMP manual must be identified in the permit application form. (Please note that this does not apply to manufactured treatment devices which are required to go through the certification and verification process as required under N.J.A.C. 7:8-5.7(c).) The alternative design along with the required documentation must submitted for evaluation to the address shown below. In order to avoid delaying the review of the Land Use Regulation permit, it is strongly recommended that this submission be made at least two months prior to the submission of the project to Division of Land Use Regulation.

Division of Water Quality
Bureau of Stormwater Permitting
PO Box 420, Mail Code 401-02B
401 E. State St., 3rd Floor
Trenton, NJ 08625-0420

Tel. (609)292-0407
Tel. (609)633-7021
Fax (609)984-2147

If the Department is not the review agency, the review agency can approve the alternative design. However, a copy of any approved alternative removal rate or method of calculating removal rate must be submitted to the Department.

An MTD with a removal rate of greater than 50% TSS can be utilized instead of a forebay in such a case. However, since the forebay is part of the requirement for a sand filter, a constructed wetland and a wet pond, the resulting removal rate is not a combination of the MTD removal rate and the non-MTD removal rate. Any use of an MTD instead of a forebay must address the scour potential and impacts on the BMP resulting from the MTD discharge.

All field permeability tests must utilize half the tested rate for the design of infiltration facilities to provide a safety factor. Furthermore, for any field tested rate of 20 inches per hour or greater, the maximum allowable design soil permeability rate shall be 10 inches per hour in order to ensure basin drawdown within 72 hours.

An impervious surface is an area that has been covered by a layer of material that is highly resistant to infiltration by water. Impervious surfaces include concrete, asphalt, driveways, basketball courts, concrete patios, swimming pools and buildings.

All of the following count as a “new” impervious surface for the purpose of the Stormwater Management rules:

• Any net increase of impervious surface onsite;
• Any change in an existing stormwater drainage system, which currently collects runoff from existing impervious surface, and the proposed change increases the capacity of the existing stormwater system (thereby potentially decreasing time of concentration, storage or water quality treatment of the existing runoff); and
• Any existing impervious surface, where the runoff is provided with existing water quality treatment, but which is proposed to be collected and discharged into a regulated area. Therefore, if existing vegetation provides water quality treatment for existing impervious surface runoff, water quality must be addressed if a project reduces or eliminates existing water quality protections. For example, runoff currently sheet-flows from a roadway onto adjacent lawns. As part of a municipal drainage improvement, a new storm sewer system will collect the runoff from the roadway and discharge it to a nearby stream. Even though there is no net increase in impervious surface, the newly collected runoff is “new” to the receiving stream. There will also be a loss of existing water quality treatment since runoff that currently sheet-flows through vegetation will now be directly discharged to the stream. As such the newly collected runoff must be treated to the existing Total Suspended Solid (TSS) removal rate, or to 50% TSS removal, whichever is greater.

New gravel is not considered impervious under the Stormwater Management rules. However, if an applicant can demonstrate that under existing conditions on a previously developed site, the gravel material performs as an impervious surface, it may be considered impervious for the purposes of redevelopment. It is important to note that gravel may be considered impervious under other Department rules.

Porous pavement is counted as impervious surface toward the threshold of jurisdiction for the applicability of the Stormwater Management rules and the applicability of the water quality standards. For instance, if 1 acre of porous pavement and 2 acres of standard pavement are proposed on a site, the total impervious surface onsite (for the purpose of determining applicability of the Stormwater Management rules) is 3 acres. However, while the water quality requirements do apply to runoff from porous pavement, the subsurface infiltration facility that is part of standard porous pavement construction will adequately address the water quality requirements of the rules, provided the subsurface infiltration facility is designed in accordance to the Stormwater Best Management Practices manual.

Any pavers with a void area of 20% or less will be considered completely impervious for the purposes of the Stormwater Management rules. In pavers with greater than 20% void area, the applicant may count only the non-void area as impervious, provided the void areas are not grouted or made impermeable in any way.

No. A completed application is not sufficient to qualify for exemption from, or satisfy the requirements of, these rules. It is during the review of the DLRP permit application that the Department will determine if the requirements of these rules have been met. If they have not, the permit will be denied.

For Flood Hazard Area Control Act, CAFRA and Waterfront Development permits, all proposed impervious surface and development onsite counts toward the thresholds.

For Freshwater Wetlands Permits and Transition Area Waivers, other than a point discharge (outfall structure), calculate the total proposed impervious surface and disturbance actually within freshwater wetlands, transition areas and open waters. If disturbance within these areas exceed either threshold, then the Stormwater Management rules apply to the entire site.

For a point discharge: if a stormwater outfall is proposed within freshwater wetlands, transition areas or open water (regardless of the type of Freshwater Wetlands permit applied for: individual permit, general permit or transition area waiver applied for), all impervious surfaces and disturbed areas draining to the proposed discharge count toward the thresholds.

Once jurisdiction is achieved for a project, the Stormwater Management rules apply to the entire project (whether within or outside an area regulated by the Department).

No. Because the only DLRP permit needed is a Freshwater Wetland permit, only development within the area that drains to the GP11 is considered when determining jurisdiction. Therefore, if the area draining to the discharge point does not exceed the threshold for “major development”, then DLUR will not apply the Stormwater Management rules to the project. However, if there are several discharge points for a proposed project within regulated areas, the cumulative drainage areas to all regulated discharge points shall be used in determining whether the definition of major development is met.

Any discharge point into a freshwater wetlands, transition area or open water may trigger the Stormwater Management rules regardless of the authorization sought for the discharge, including discharge into the pre-activity transition area. All proposed activities in the entire inflow area to the discharge point count toward jurisdiction. However, if neither the 0.25 of an acre or 1 acre threshold were exceeded as a result of the proposed activities in the inflow area, then the Stormwater Management rules would not apply. In such a case, the proposed activity would be understood to have a de minimus impact on the transition areas, and the prohibition at N.J.A.C. 7:7A-6.2(b)3 does not apply.

If there is no regulated transition area onsite, only the freshwater wetlands and open water disturbance would count toward the threshold, unless the disturbance includes a discharge point, in which case the proposed activities in the cumulative drainage areas to all regulated discharge points shall be used to determine whether the definition of major development is met.

No. An LOI approves a wetlands boundary and does not approve construction activities. Since no construction is proposed at this time, the project does not meet the definition of major development. Should the applicant eventually propose construction onsite requiring a Division of Land Use Regulation permit, the project would be evaluated upon submittal to the Department to determine if it is a “major development”.

Not for the purposes of obtaining a Verification. Establishing the limit of the flood plain and riparian zone simply sets a jurisdictional boundary similar to setting a wetlands boundary under an LOI. Should the applicant eventually propose construction onsite requiring a Division of Land Use Regulation permit, the project would be evaluated upon submittal to the Department to determine if it is a “major development”.

Yes. The Stormwater Management rules apply to any activity authorized under N.J.A.C. 7:7A that exceeds the jurisdictional thresholds.

Any activity proposed onsite after February 2, 2004, counts when determining jurisdiction under the Stormwater Management rules. Under Phase 1 as described above, the project did not meet the definition of “major development” and so the rules did not apply. However, under Phase 2, the total amount of disturbance occurring after February 2, 2004, exceeds the jurisdictional limits. As such, all construction under Phase 2 must meet the new standards. Since Phase 1 is already approved, the Department will not force the applicant to retrofit the project to meet the Stormwater Management rules for the Phase 1.

It was not the intent of the Stormwater Management rules to capture these types of projects. Although more than 1 acre of land is disturbed, the Department will not require stream-cleaning projects to meet the Stormwater Management rules since this type of project will not significantly affect groundwater recharge, runoff quantity or water quality.

As with Question 11.11 above regarding stream-cleaning projects, bank stabilization projects will not significantly affect groundwater recharge, runoff quantity or water quality. In fact, bank stabilization often reduces erosion and promotes healthy riparian corridors, thus improving water quality. As such, the Department will not require bank stabilization projects to meet the Stormwater Management rules.

The area of the project that drains into the GP11 discharge is grandfathered from all new requirements of the Stormwater Management rules. However, if any portion of the project needs a Flood Hazard Area Control Act permit and the overall project meets the definition of major development, any portion of the project not covered by the GP11 will be subject to the Stormwater Management rules.

DLUR cannot extend the GP11 because the rules governing the GP11 have changed by virtue of the adoption of the new Stormwater Management rules. Therefore, once the GP11 expires, the project is no longer grandfathered. If the applicant wishes to receive a new GP11, the project must be redesigned to meet the standards of the Stormwater Management rules.

Since, in this case, the project is grandfathered until 2010, DLUR would extend the GP11 so that it would expire along with the FHACA permit (thus the extension to the GP11 would be for less than five years). However, if the project requires local approval or if such local approvals expire prior to 2010, and the project meets the definition of “major development”, the project may be subject to the Stormwater Management rules through that local approval process.

The rules that implement buffers around C1 waters are the Stormwater Management rule (N.J.A.C. 7:8) and the Flood Hazard Area Control Act rule (N.J.A.C. 7:13). Projects are grandfathered as follows when a stream is upgraded to C1:

Pending and previously approved projects: If the project has a valid Division of Land Use Regulation (DLUR) permit or an application deemed complete by the Department prior to the effective date of a C1 designation, it is not subject to the requirements made applicable by the new designation.

Projects that did not need a Flood Hazard Area Control Act (FHACA) permit prior to a new C1 designation, but are now located within the C1 buffer:

• Projects with municipal approval, issued prior to the effective date of the C1 designation, that enables commencement of construction will not require a FHACA permit.
• Projects that did not need a municipal approval and began construction before the effective date of the C1 designation as evidenced by: the foundation for at least one building or structure; all of the subsurface improvements for a roadway; or the installation of all of the bedding materials for a utility line, will not require a FHACA permit.

In all cases, if the project changes such that a new permit application is required, the designation in effect at the time of the new application will apply.

The Stormwater Management rules do not affect the jurisdiction or requirements of municipal planning boards under the Municipal Land Use Law. Planning Boards should continue to exercise their authority under the Municipal Land Use Law, reviewing projects for compliance with their existing stormwater control ordinances. Municipalities should be reviewing residential development for compliance with the Stormwater Management rules under the Residential Site Improvement Standards. Once revised municipal stormwater control ordinances are effective, the municipality must utilize the stormwater ordinance.

Pursuant to the federal mandate, municipalities must review projects that disturb one acre or more. However, certain municipalities have incorporated the requirement for the municipal review utilizing smaller thresholds. The applicant should always verify the trigger for incorporating the requirements of the stormwater management rules with each municipality.

Municipal ordinances can be amended to be more stringent than the requirements of the Stormwater Management rules, but not to be more lax. The Residential Site improvement Standards (RSIS) allow municipalities to require stormwater runoff controls for development falling below major development to address groundwater recharge and stormwater runoff quantity, but not for water quality as provided in the RSIS at N.J.A.C. 5:21-7.1.

The applicant is required to provide mitigation, unless the project has received a waiver for the performance standard from the Department. For those situations, the necessity to provide mitigation based on the stormwater management requirements are at the discretion of the municipality.

Yes.

The Stormwater Management rules do not supersede the Pinelands CMP. Therefore, both sets of requirements must be addressed, where applicable. However, the Pinelands CMP has been revised to be in compliance with the requirements of the Stormwater Management rules. In addition, the Stormwater Control Ordinance for Pinelands Municipalities has been provided for adoption by Pinelands municipalities to ensure compliance with both regulations.

Both the Pinelands Comprehensive Management Plan and the Model Ordinance require the use of the USDA-NRCS Runoff Equation, Runoff Curve Numbers, and Dimensionless Unit Hydrograph. The reference to the use of alternative methods is provided to recognize that the adoption of a regional stormwater management plan may result in alternative computational methods, and may supersede this standard if adopted. However, unless a regional stormwater management plan has been adopted by the Department, certified by the Pinelands Commission, and specifically revises the computational methods, alternative computational methods may not be utilized to comply with this requirement.

The Stormwater Management rules apply to all major development. The amended rule defines
“Major development” as any individual “development,” as well as multiple developments that individually or collectively result in:

1. 1. The disturbance of one or more acres of land since February 2, 2004;
2. The creation of one-quarter acre or more of “regulated impervious surface” since February 2, 2004;
3. The creation of one-quarter acre or more of “regulated motor vehicle surface” since March 2,2021; or
4. A combination of 2 and 3 above that totals an area of one-quarter acre or more. The same surface shall not be counted twice when determining if the combination area equals one quarter acre or more.

Major development includes all developments that are part of a common plan of development or sale (for example, phased residential development) that collectively or individually meet any one or more of conditions 1, 2, 3, or 4 above. Projects undertaken by any government agency that otherwise meet the definition of “major development” but which do not require approval under the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq., are also considered “major development.”

In addition, local government units may impose a stricter threshold than what is defined as major development in the amended rule. Local government units will need to adopt ordinances specifying whether they are using this State standard or a more stringent threshold requiring green infrastructure.

A: The Department adopted amendments to the Stormwater Management rules, N.J.A.C. 7:8, to replace the current requirement that major developments incorporate nonstructural stormwater management strategies to the “maximum extent practicable” to meet groundwater recharge standards, stormwater
runoff quantity standards, and stormwater runoff quality standards, with a requirement that green infrastructure (GI) be utilized to meet these same standards.

A: The adopted amendments clarify and modify the definition of major development, which defines the scope of projects to which these rules apply. The Department adopted changes to apply the total suspended solids (TSS) removal requirement to the runoff from motor vehicle surfaces and to eliminate the TSS removal requirement as it applies to runoff from other impervious surfaces not traveled by automobiles, such as rooftops and sidewalks. The Department also adopted several changes that will improve water quality and stormwater management improvements in communities with combined sewer systems. This adoption makes changes to existing definitions, such as the definition of “Tidal Flood Hazard Area,” and adds new definitions, such as “Green Infrastructure” and “New Jersey Stormwater BMP Manual.” Other adopted amendments make other alterations related to the changes identified above, as well as other minor changes to other provisions in the Stormwater Management rules. Additionally, the Department adopted minor amendments to the Coastal Zone Management Rules, the Freshwater Wetlands Protection Act Rules, the Flood Hazard Area Control Act Rules, the New Jersey Pollutant Discharge Elimination System rules, and the Highlands Water Protection and Planning Act Rules in order to update cross-references and incorporate other changes consistent with the amendments to the Stormwater Management rules.

A: “Green infrastructure” means a stormwater management measure that manages stormwater close to its source by:

1. Treating stormwater runoff through infiltration into subsoil;
2. Treating stormwater runoff through filtration by vegetation or soil; or
3. Storing stormwater runoff for reuse.

A: Green Infrastructure best management practices (BMPs) are intended to mimic natural hydrologic conditions and, thus, typically incorporate infiltration and/or vegetation more than traditional stormwater management methods.

A: The main stormwater related benefit of GI vs traditional methods of managing stormwater is stormwater volume reduction. While, as noted in the definition of GI at N.J.A.C. 7:8-1.2, there are three mechanisms by which GI systems can work, each of the three results in at least some portion of the volume of stormwater being retained by the BMP. Thus, that portion of the stormwater (and any pollutants it would have carried) never reaches downstream conveyance systems or watercourses. This will result in both reduced flooding and improved water quality in watercourses, since the retained portion of the stormwater never reaches the downstream watercourse. By contrast, more traditional stormwater management systems do not generally retain a significant amount of stormwater runoff. GI also results in numerous non-stormwater co-benefits to communities, including reduction in urban heat island effect, decreased energy use, removal of pollutants from the air through greater utilization of vegetation, beautification of public spaces, and increased property values.

A: The most widely used GI stormwater BMP is the rain garden, which is a type of small-scale bioretention system. Other examples of green infrastructure BMPs include green roofs, dry wells, pervious paving systems, infiltration basins, cisterns, and even certain types of manufactured treatment devices. For more information on BMPs, please see the New Jersey Stormwater BMP Manual, which is available at NJ Stormwater Best Management Practices Manual

A: Yes. The amended rules require stormwater runoff to be managed by GI BMPs with smaller scale GI BMPs required in most cases. The drainage area limits are intended to ensure that the GI BMPs utilized are small scale which is important in ensuring that the BMP maintains or mimics natural hydrology and
manages stormwater runoff close to its source. Drainage area limits are applicable to dry wells (1 acre), manufactured treatment devices (2.5 acres), small-scale bioretention systems (2.5 acres), small-scale infiltration basins (2.5 acres), small-scale sand filters (2.5 acres), and pervious paving systems (area of additional inflow cannot exceed three times the area occupied by the BMP.)

A: Yes, while developing in urban areas comes with additional challenges, there are a wide variety of GI BMPs that can be utilized in urban areas. The Department expects that the implementation in urban settings will realize co-benefits such as reductions in the urban heat island effect, decreased energy use, removal of pollutants from the air through greater utilization of vegetation, beautification of public spaces, and increased property values in areas where they are most needed. For more information on the specific limitations of BMPs, please see the New Jersey Stormwater BMP Manual, which is available at NJ Stormwater Best Management Practices Manual

A: GI is widely recognized to be a cost-effective and resilient approach to managing stormwater while simultaneously providing environmental, social, and economic co-benefits. Since GI is typically distributed and small scale, developers may have to install multiple GI BMPs on a single major development site to manage stormwater, whereas under the current rules fewer larger stormwater management BMPs may be sufficient. Costs will vary depending on the scope of the project and the BMPs chosen. However, in general the Department expects no significant increased cost to property owners who assume the cost of operation and maintenance of GI.

A: Yes, the NJ Water Bank provides low interest loans through the clean water state revolving fund to owners of publicly-owned treatment works with GI projects that help protect, maintain or improve water quality. Private entities are eligible through public conduit borrowers. Project sponsor eligibility has also been expanded to private colleges and universities that are interested in sponsoring nonpoint source pollution projects. Combined Sewer Overflow (CSO) abatement projects utilizing GI are eligible to receive principal forgiveness (grant like funding) for up to 50% of project costs (principal forgiveness capped at $2Million). Water quality restoration grants are also awarded by the Department to fund watershed restoration activities and initiatives around New Jersey that address nonpoint source pollution (NPS). Funding sources include USEPA pass-through grants issued under Section 319(h) of the federal Clean Water Act (CWA) and other federal and State funds that may be available for NPS-related water quality restoration activities. For more information on available financing, visit our website at https://www.nj.gov/dep/gi/.

A: The adopted rules support water quality and stormwater management improvements in communities with combined sewer systems (CSS). The adopted rules clarify the applicability of the water quality standards for discharges into a CSS (N.J.A.C. 7:8-5.5(c)); require quantity control in tidal flood hazard areas (unless the design engineer demonstrates through hydrologic and hydraulic analysis that the increased rate, increased volume, or both of stormwater runoff will not result in additional flood damage below the point of discharge (N.J.A.C. 7:8-5.6(b)4)); expand the municipality’s planning flexibility for CSOs and flood control (N.J.A.C. 7:8-4.2(c)14); and provide differing applicability of GI requirements to sewer separation projects to make them more feasible (N.J.A.C. 7:8-5.3(e)). For information regarding the evaluation of GI as part of the development of Long Term Control Plans to address CSOs.

A: Yes. The amendments do not specifically restrict the use of MTDs, instead, they require the use of GI. While most MTDs do not qualify as GI, there are MTDs that do. Furthermore, MTDs for road projects with a waiver from strict compliance, pre-treatment of certain other BMPs, retrofits of existing BMPs, and projects that are not major development will be unaffected by these changes. For a list of Department certified MTDs.

A: These amendments will become operative on March 2, 2021.

A: Yes. The Stormwater Management rules represent the minimum standard for municipal stormwater control ordinances. Therefore, municipal stormwater control ordinances must be revised to be consistent with these amendments.

A: Municipalities have until March 3, 2021 for their revised ordinance to become effective. However, a municipality can choose to make their ordinance effective sooner.

A: For applications submitted to the Department’s Division of Land Use Regulation, any technically complete application received prior to March 2, 2021 will be subject to the existing Stormwater Management rule. Similarly, any application submitted to a municipality that includes both the application form and all accompanying documents required by ordinance will be subject to the ordinance in effect at the time of application.

A: As indicated in the notice of proposal Summary, 50 N.J.R. at 2376, the Department is in the process of seeking input regarding potential further amendments to the Stormwater Management rules. In response to the notice of proposal associated with these adopted amendments, the Department received comments that were beyond the scope of anything proposed in this rulemaking. The Department will consider the input provided by those comments as it determines what further amendments to the rules may be appropriate in a future rulemaking. Information from the stakeholder meetings can be found at https://njdepwptest.net/workgroups/.

A: In part, the adopted amendments are intended to make the State more resilient to storm and flood impacts from climate change through the use of GI. Additionally, GI BMPs will help fight against climate change by creating carbon-sequestering green space. However, the development of a second phase of
rule changes is underway to advance Governor Murphy’s climate change goals called for in the NJProtecting Against Climate Threats (NJ-PACT) initiative directed by Executive Order 100. The DEP anticipates proposing these amendments this year.

Pursuant to Part IV.A.1.b. of the municipal separate storm sewer system permit (MS4 permit), municipalities shall update their stormwater control ordinance(s) within 12 months of written notification by the Department of the need for modification and update. Notification was provided to all MS4 municipalities on 7/17/2023. So, municipalities have 1 year from that date to have a revised ordinance in effect. County approval is required before the ordinance will become effective. Please ensure to build in sufficient time to receive the County approval to ensure the ordinance is effective by the deadline. 

A major development that requires any of the Department permits listed at N.J.A.C. 7:8-1.6(c) and also needs a municipality’s stormwater management review will be affected by the rules immediately on July 17, 2023, unless a technically complete application was submitted to the Department prior to July 17, 2023. When a major development that does not require any of the Department permits listed at N.J.A.C. 7:8-1.6(c), but needs a stormwater management review by a municipality,  the municipal review will be affected by the rules and will depend on the following circumstances: 

a. If a major development is a residential development, the major development project will be subject to the rules adopted on July 17, 2023, unless both the application form and all accompanying documents required by ordinance have been submitted to the municipality prior to July 17, 2023; 

b. If a major development is not a residential development, the major development project submitted with both the application form and all accompanying documents required by ordinance will be subject to the currently effective municipal stormwater control ordinance(s) at the time of application submission; and

c. If a major development is subject to the jurisdiction of the Pinelands Comprehensive Management Plan (Pinelands CMP), the major development submitted with both the application form and all accompanying documents required by ordinance and the Pinelands CMP will be subject to the currently effective Pinelands CMP and the ordinance authorized thereof at the time of application submission. 

A major development that requires any of the Department permits listed at N.J.A.C. 7:8-1.6(c) and also needs a municipality’s stormwater management review will be affected by the rules immediately on July 17, 2023, unless a technically complete application was submitted to the Department prior to July 17, 2023. When a major development that does not require any of the Department permits listed at N.J.A.C. 7:8-1.6(c), but needs a municipality’s stormwater management review will be affected by the rules will depend on the following circumstances: 

a. If a major development is a residential development, the major development project will be subject to the rules adopted on July 17, 2023, unless both the application form and all accompanying documents required by ordinance have been submitted to the municipality prior to July 17, 2023; 

b. If a major development is not a residential development, the major development project submitted with both the application form and all accompanying documents required by ordinance will be subject to the currently effective municipal stormwater control ordinance(s) at the time of application submission; and

c. If a major development is subject to the jurisdiction of the Pinelands Comprehensive Management Plan (Pinelands CMP), the major development submitted with both the application form and all accompanying documents required by ordinance and the Pinelands CMP will be subject to the currently effective Pinelands CMP and the ordinance authorized thereof at the time of application submission. 

As defined in the Coastal Zone Management Rules at N.J.A.C. 7:7-1.5, the Freshwater Wetlands Protection Act Rules at N.J.A.C. 7:7A-1.3, and the Flood Hazard Area Control Act rules at N.J.A.C. 7:13-1.2, “technically complete” means that each item included in an application provides sufficient information for the Department to declare the application complete for review, public comment, or public hearing.   

N.J.A.C. 7:8-1.2 defines “public transportation entity” as “a Federal, State, county, or municipal government, an independent State authority, or a statutorily authorized public-private partnership program pursuant to P.L. 2018, c. 90 (N.J.S.A. 40A:11-52 et seq.), that performs a public roadway or railroad project that includes new construction, expansion, reconstruction, or improvement of a public roadway or railroad.” Thus, in addition to NJDOT projects, the definition includes projects by New Jersey Transit, New Jersey Turnpike Authority, South Jersey Transportation Authority, Port Authority of New York and New Jersey, Delaware River Joint Toll Bridge Commission, and similar entities. Further, any public transportation project proposed by a political subdivision of the State such as a county or municipality is included in this definition and is eligible to seek flexibility under N.J.A.C. 7:8-1.6 and N.J.A.C. 7:13-12.6(b). It is appropriate to extend flexibility to all levels of government proposing public transportation projects since the challenges facing public infrastructure are not unique to each level of government. However, as stated in the proposal at 54 N.J.R. at 2174, a roadway constructed as part of a private development project, regardless of whether the roadway is ultimately to be dedicated to and/or maintained by a government entity, is not within the definition of public roadway or railroad. While public roadways constructed by the listed public entities are subject to unique constraints that can impact the ability of such a project to comply with stormwater requirements, such unique circumstances are not present in roadways constructed as part of a private development project. An internal roadway that is part of a private development project will often have a greater amount of adjacent area owned by the private entity within which to incorporate stormwater BMPs. As such, roadways constructed as part of a private development do not require the same flexibility being afforded to public roadways. 

The Rational Method for calculating stormwater peak flow rate and the Modified Rational Method for the hydrograph computations have been removed from the Stormwater Management rules at N.J.A.C. 7:8 et seq. Therefore, the Rational Method and Modified Rational Method cannot be used in the design, routing calculations, and sizing of stormwater best management practices, including manufactured treatment devices, for major developments subject to N.J.A.C. 7:8, stormwater control ordinances adopted pursuant to N.J.A.C. 7:8, and other rules that refer to N.J.A.C. 7:8. However, storm sewer or drainage system design pursuant to the Residential Site Improvement Standards under N.J.A.C. 7:21-7.2(c)5 is not under the jurisdiction of N.J.A.C. 7:8. Therefore, the Rational Method and Modified Rational Method may still be used for the storm sewer or drainage system design. 

The groundwater recharge standards at N.J.A.C. 5.4(b)1ii have been amended to require that the projected 2-year storm be utilized in the groundwater recharge calculations if that method of compliance is selected by the design engineer, but N.J.A.C. 7:8-5.4(b)1 that requires the maintenance of the average annual pre-construction groundwater recharge volume remains unchanged. Further, the overall amendments require the use of updated and projected rainfall data for the two-, 10-, and 100-year storm events, rather than annual rainfall totals. Regarding the groundwater recharge spreadsheet, the Department continues to reexamine and revise the BMP Manual (in which the spreadsheet is contained) when new information and/or data become available. As such, the Department may update the groundwater recharge spreadsheet’s annual rainfall in the future. 

The adjustment factors adopted into the rules apply only to the two, 10-, and 100-year storm events and do not alter the definition, intensity or volume of the water quality design storm. The water quality design storm is set at one and one-quarter inches of rainfall, rather than being tied to a specific return frequency like the two-, 10-, and 100-year storm. The rainfall of the two-, 10-, and 100-year storms need to be adjusted to maintain the same return frequency for those storms. Since the water quality design storm is set at a specific rainfall total, it does not require adjustment. 

Chapter 5, Computing Stormwater Runoff Rates and Volumes, and Chapter 6, Groundwater Recharge, of the BMP Manual have been updated in accordance with the rules. The updated Chapter 5 includes the calculation of precipitation depths of the current and projected two-, 10-, and 100-year storm events and design examples using small-scale green infrastructure stormwater BMPs to meet the stormwater quality, stormwater quantity, and groundwater recharge standards. The Department will continuously update individual chapters in the BMP Manual when there are rule amendments or a necessary update to the technology.