O30 Princeton Hydro Report Dated 9 3 25

PRINCETON SCIENCE ENGINEERING DESIGN ——_ HY DRO Dr. Robert Bagoff, Chair September 3, 2025 West Orange Planning Board 66 Main Street West Orange, NJ 07052 0 \z & RE: PB-24-01 West Essex Highlands, Inc Block: 179 Lot: 32 Zone: IH-1 Warner Road West Orange Township, Essex County, New Jersey Dear Dr. Bagoff, At the request of attorney Bruce Afran, counsel for objectors and We Care NJ Corp., Princeton Hydro has prepared a response to the CME letter dated August 15, 2025 which was addressed to the Chairman and Members of the West Orange Planning Board responding to Princeton Hydro's March 10, 2025 review of the stormwater management system for the above referenced application. Without providing substantial supporting details or evidence, the CME letter generally states that proposed stormwater system is compliant with New Jersey Department of Environmental Protection (NJDEP) design standards and requirements found in NJAC 7:8 and the NJDEP Best Management Practices (BMP) Manual. In lieu of providing any notable supporting reasoning, details or evidence, CME instead simply states and reiterates that the “...Department has determined that this project meets the requirements of the Stormwater Management Rules”. In fact, in reference to two critically important points (Time of Concentration calculation and groundwater mounding analysis) the CME letter confirms that they found “some discrepancies” as they relate to both of these key points. However, instead of describing these “discrepancies” to any extent or offering any critical response to the detailed issues outlined in our original letter, they simply state the NJDEP has issued a permit. As the Municipal Engineer for the Township of West Orange one of their responsibilities is to ensure the stormwater design meets the requirements of the local ordinance. As a Township consultant, they are charged with providing an accurate and independent review of the stormwater system for the proposed West Essex Highlands development. The applicant's ability to secure an NJDEP permit does not relieve CME from their responsibility to provide an accurate, objective and independent analysis of the proposed stormwater plan with respect to the local ordinance. In the following sections we respond to key elements of the CME letter. With respect to the applicant's reported site-wide total lack of any seasonal high

r plan with respect to the local ordinance. In the following sections we respond to key elements of the CME letter. With respect to the applicant's reported site-wide total lack of any seasonal high groundwater indications, the CME letter states: ...[T]he New Jersey Stormwater Best Management Practices Manual (NJ BMP Manual) notes that there are instances where mottling can be absent from a soil profile, therefore, observing mottling in a soil profile is not a requirement. Further, Chapter 12 of the NJ BMP Manual specifically outlines the methods for determining the seasonal high-water table (SHWT) when mottling is not observed in a soil profile. Therefore, based on our review, the Applicant's Engineer's method of determining the SHWT is consistent with the NJ BMP Manual. The NJDEP BMP Manual Chapter 12 Subsection 1d: Seasonal High Water Table (SHWT) Location #1 (page 12) states the following: Where mottling showing redoximorphic features is observed at any season of the year, the SHWT shall be taken as the highest level at which the mottling is observed, except when the water table is observed at a level higher than the level of the redoximorphic depletions or concentrations. For 08-237-5660 P.O. Box 3689 enton, NJ 08629

PB-24-01 West Essex Highlands, Inc. Block No. 179, Lot No.32, West Orange Township, Essex County, New Jersey September 2025 details on determining whether saturated soils are present, the guidance document published by NRCS, "Field Indicators of Hydric Soils in the United States” may be used. When developing soil logs for test pits, one must look for mottling at any season. Not once was mottling observed in the soil logs and never do the logs follow the guidance found in the “Field Indication of Hydric Soils in the United States”. Princeton Hydro performed their own soil logs just outside of the property boundary in a few different locations and found evidence of mottling. These soil logs have been provided to the Board. A reasonable person is left to conclude that the only reason redoximorphic features were not noted is that the person documenting the test pits was not looking for them. The NJDEP BMP Manual requires one to specifically look for evidence of seasonal high groundwater and in the rare occasion it is not found, only then can alternative methods be used to establish the SHWT. Princeton Hydro believes that the person responsible for these soil logs should provide testimony about the methodology they used to document the soil logs. In addition, CME's position that applicant's engineer's method of determining the SHWT is consistent with the NJ BMP Manual is an overly simplistic interpretation of the Manual's requirements. For example, the soils mapped on the development site and shown of the applicant development plans possess a restrictive horizon or fragipan. The NJDEP BMP Manual has specific requirements for logging soils (Subsection 2c, page 22) that includes the identification of restrictive horizons such as a fragipan. Not a single soil log identified a restrictive horizon. The NJDEP BMP Manual also requires “the depth, or the elevation and thickness of each soil horizon" and that the soils are colored using the Munsell system of classification for hue, value and chroma. The soil horizons described appear to lump layers into several feet thick soil layers. This approach is not consistent with the NJDEP BMP Manual and fails to identify discrete horizons that may include restrictive horizons as should be expected based on the soil mapping. As stated in the Princeton Hydro report of April 29, 2025 (Attachment A) the failure to identify any

te horizons that may include restrictive horizons as should be expected based on the soil mapping. As stated in the Princeton Hydro report of April 29, 2025 (Attachment A) the failure to identify any restrictive horizons and seasonal high-water table will have a substantial impact on the functioning of the proposed stormwater management system. This resulting design deficiency has real and tangible impacts on downstream residents as it relates to the rate and volume of runoff from the property. It is the sole responsibility of CME to ensure that the proposed system functions in a manner that will satisfy the local ordinance. Despite noting “some discrepancies” on two key comments, the recent CME letter serves to simply document CME's attempt to deflect this responsibility. With respect to the critical issue of peak flow (flood) control and specifically the Time of Concentration calculations, the CME letter states the following: ... Alternative stormwater management measures, removal rates, or calculation methods may be utilized, subject to any limitations specified in this chapter, provided the design engineer demonstrates to the review agency, in accordance with N.J.A.C. 7:8-5.2(g), that the proposed measure and its design will contribute to achievement of the design and performance standards established by this chapter. Although N.J.A.C. 7:8 does allow for alternative stormwater management measures, removal rates or calculation methods, these alternative measures require justification to demonstrate the unique nature of the situation that dictated the need for the alternative method. Section N.J.A.C. 7:8-5.2 (g) states the following: An alternative stormwater management measure, alternative removal rate, and/or alternative method to calculate the removal rate may be used if the design engineer demonstrates the capability of the proposed alternative stormwater management measure and/or the validity of the alternative rate or method to the review agency. However, no justification, documentation or additional context is provided by the Applicant for the use of alternative methods. The justification for each alternative stormwater measure used by the applicant should have been identified by CME and shared with the public in their August 15" letter. Instead, the CME letter uses this generic reference to alternative methods to justify multiple design

pplicant should have been identified by CME and shared with the public in their August 15" letter. Instead, the CME letter uses this generic reference to alternative methods to justify multiple design features, including the time of concentration calculations, despite the fact that these approaches contradict the NJDEP BMP Manual and standard engineering practice as outlined in our March 10, 2025 letter. Princeton Hydro, LLC: 2151.002 2

gz PB-24-01 West Essex Highlands, Inc. Block No. 179, Lot No.32, West Orange Township, Essex County, New Jersey September 2025 With respect to the Time of Concentration calculation the CME letter concedes the following: Our office agrees that there appears to be some discrepancies with the time of concentration calculation methodology completed by the Applicant's Engineer as compared to the methodology outlined in the BMP Manual. If CME's review revealed discrepancies regarding the Time of Concentration calculation methodology, they have an obligation to outline these discrepancies, especially considering the critical implications it has for downstream residents of the Township. However, the CME letter offers no further discussion of these discrepancies and instead simply again deflects their responsibility to the NJDEP. On the contrary, Princeton Hydro was clear in the March 10, 2025 letter that part of the issue with the time of concentration calculations was not just using different velocity factors which could be classified as an “alternative method” but that the basic underlying analysis of the drainage area was incorrectly executed. Two points of analysis cannot have one drainage area and the flow path to the point of analysis was not complete, stopping several hundred feet short and thereby artificially elevating the existing peak flow rates (thus artificially reducing the necessary size of the stormwater system). The CME letter suggests that alternative methods were used but does not provide any justification for the applicant's methodologies, nor does the CME letter attempt to illustrate how the alternative method complies with the Township's stormwater ordinance. Most importantly, CME other than agreeing that there are “some discrepancies", the CME letter does not offer any objective analysis or professional opinion on whether or not the applicant's approach is sound. As the Township's consulting engineer, CME should not attempt to justify an incorrect analysis by stating that it is simply an alternative stormwater methodology, instead they have a responsibility to objectively analyze the applicant's stormwater design. This is especially relevant in this context as the 100-year storm for the proposed project would, contrary to the stormwater rules, actually generate higher peak flow rate than what currently exists (see Attachment A

ly relevant in this context as the 100-year storm for the proposed project would, contrary to the stormwater rules, actually generate higher peak flow rate than what currently exists (see Attachment A pages 19-21). This is an important issue for the Township representatives to consider as there are well-documented flood- prone areas immediately downstream of the proposed development. In order to meet the peak flow rate requirements set forth by the local ordinance, our analysis has shown that the design would need to be substantially changed to increase storage in the proposed stormwater system and this would likely have a substantial impact on the current overall site design. The CME letter concedes that the number of soil explorations is not compliant with the NJDEP BMP Manual but states that the applicant worked with the NJDEP to determine the number of required soil explorations for the development prior to completion. It is not clear if CME has an explanation for the change of requirements from the NJDEP or the applicant as it relates to this key issue. That justification should be provided as part of the application to the board. With respect to the groundwater mounding calculations, here again the CME letter states that: Our office agrees that there appears to be some discrepancies with the groundwater mounding calculation methodology completed by the Applicant's Engineer as compared to the methodology outlined in the BMP Manual. Again, the CME letter fails to outline or offer any additional information on these discrepancies, and instead deflects this responsibility on the pretense of an NJDEP permit. The CME letter states that the sanitary sewer piping will not be installed within any of the stormwater management systems. The applicant's engineer will be required to revise the plans prior to construction. However, as shown in Figure 1 below, the sanitary sewer is surrounded by wetlands. Therefore, relocating this pipe will most likely require additional wetlands permitting; a fact and supporting context/information not provided by the CME letter. Princeton Hydro, LLC: 2151.002 3

PB-24-01 West Essex Highlands, Inc. Block No. 179, Lot No.32, West Orange Township, Essex County, New Jersey September 2025 The relocation of the sanitary sewer out of a proposed stormwater management feature represents the only instance where CME as the municipal engineer is requiring the applicant to revise the plans, while they chose to defer to the NJDEP in all other instances. As stated in our original letter, this design feature is inconsistent with sound engineering practices. Although CME did not appear to take issue with this design flaw in their latest review letter, CME has a responsibility to provide an explanation why they chose to defer to the NJDEP on multiple critical design issues (Time of Concentration methodology/analysis and groundwater mounding) and why they chose not to defer on this issue. It is also important for the public to see a revised plan to understand how the applicant contemplates addressing this issue and how a modified design would achieve compliance with the Township's ordinance while also satisfying NJDEP freshwater wetland and flood hazard area regulations. We appreciate the opportunity to provide you with these engineering services for you. Please do not hesitate to contact us with any questions regarding this review. Sincerely ACA <t Sean Walsh, PE Clay Emfrson PhD PE CFM Senior Project Manager Senior Téchnical Director Attachment: Princeton Hydro April 29, 2025 Letter to NJDEP Princeton Hydro, LLC: 2151.002 a

i PRINCETON SCIENCE ENGINEERING DESIGN =f DRO April 29, 2025 Colleen Keller Watershed & Land Management Program New Jersey Department of Environmental Protection Bureau of Coastal & Land Use Compliance & Enforcement Mail Code 501-02A 501 East State Street PO Box 420, Trenton, NJ 08625-0420 colleen.keller@dep.nj.gov RE: — PB-24-01 West Essex Highlands, Inc Block: 179 Lot: 32 Zone: IH-1 Warner Road West Orange Township, Essex County, New Jersey Permit No. 722-04-0001.1 LUP230001 Dear Ms. Keller, At the request of our clients, We Care NJ Corp., Princeton Hydro, LLC has performed an independent technical review of the proposed West Essex Highlands development project (hereinafter termed Project) located in West Orange Township, New Jersey as part of the municipal Planning Board approval process. The applicant, West Essex Highlands received a permit, No. 722-04-0001.1 LUP230001, for activities regulated under the Freshwater Wetland Protection Act and Flood Hazard Area Control Act. NJDEP. It is our understanding that the New Jersey Department of Environmental Protection (NJDEP) reviewed the stormwater management plan for compliance with the New Jersey Stormwater Best Management Practices Manual (BMP Manual) and the Stormwater Management rules at N.J.A.C. 7:8 as part of the issuance of Permit No. 722-04-0001.1 LUP230001. The permit states “[t]he Department has determined that this project meets the requirements of the Stormwater Management rules at N.J.A.C. 7:8.” Although approved by the NJDEP, Princeton Hydro's review of the Township submission identified substantial issues regarding the project's stormwater management design that fail to comply with the requirements of New Jersey's Stormwater Management Rules as well as the New Jersey BMP Manual. One of the concerns regarding this project is that municipalities often view the NJDEP as the state's stormwater expert since they developed the regulations as well as the municipal ordinance that municipalities must review development projects for compliance. When the NJDEP grants a permit prior to or during the municipal review process, municipalities are often pressured by applicants into issuing an approval based simply on the fact that the NJDEP already granted a permit. However, in this case the municipality is confronted with a number of serious compliance issues related to the Site’s stormwater

roval based simply on the fact that the NJDEP already granted a permit. However, in this case the municipality is confronted with a number of serious compliance issues related to the Site’s stormwater management plan that should ultimately result in the denial of the application. It is in this light that we request the NJDEP suspend the permit based on the conditions set forth at N.J.A.C. 7:13-22.7 Suspension of a ‘> PrincetonHydro.com ©