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West Essex Highlands Review 2 West Orange, NJ Permit No. 722-04-0001.1 LUP230001 April 2025 unusual, but as emphasized in the New Jersey BMP Manual, soil mottling/redoximorphic features should be used to establish the SHWT. The New Jersey BMP Manual also requires the identification of any “soil restrictions including, but not limited to, abrupt textural boundaries likely to restrict the movement of water, e.g., fragipans, dense materials, bedrock and ortstein horizons.”5 Importantly, soil logs must also be specific in their identification of various colors and textures throughout a profile, as is consistent with the Field Indicators of Hydric Soils in the United States referenced by the New Jersey BMP Manual. Color identification is key in correctly identifying mottling by recording the value and chroma of the observed colors which can then be used to properly describe (calculate) the contrast of the mottles. When applying the methods set forth in the New Jersey BMP Manual it is difficult to believe that redoximorphic features would not be present in the surface soils as three of the more extensive soil series on the Site are expected to possess a fragipan and perched water tables. To determine if the soils on the Site possessed redoximorphic features as described in the USDA's Official Soil Series Descriptions (Attachment A) Princeton Hydro collected soils data at four locations on the adjacent property to the south (Attachment B). The four borings were in Booton and Haledon Soils. All of the borings taken by Princeton Hydro showed that the soils possessed redoximorphic features. The soils data collected by Princeton Hydro support our concern that the perched water table described in the USDA's official soil descriptions was missed and that the SHWT is much higher than indicated. An accurate understanding of the soils as well as onsite hydrology is essential to a stormwater design that meets the NJDEP’s minimum requirements. The original soil investigation on the Site was performed by Sor Consulting Engineers. Soil investigations were done on four separate occasions. Based on the review of the soils data provided in the four Sor Consulting Engineers reports, it is apparent that the SHWT was only established using the elevation of the observed water found in the test pits or borings. It is also important to point out that it does not appear that the

ports, it is apparent that the SHWT was only established using the elevation of the observed water found in the test pits or borings. It is also important to point out that it does not appear that the analysis of the surface soils was done with a sufficient level of detailed analysis that could have documented the presence of mottling or other evidence of a SHWT. For example, in the Sor Consulting Engineers report dated May, 23, 2023, the report described the soils in TP-C1 and TP-C2 as “[t]ne topsoil was underlain by clayey soil and extended to a depth of 3.5 to 4 feet below the surface.”* Based on the Official Series Description for a Boonton or Haledon Soil one should expect to observe five distinct soil layers within 48 inches of the surface not two. It should also be noted that neither “topsoil” nor “clayey soil” are soil textures according to the NRCS classification. As noted in the New Jersey BMP Manual, there are instances where mottling can be absent from a soil profile, but it is highly unusual that mottling was not found in any of the soil test pits provided by the applicant, especially since these soil series possess a SHWT related to the presence of perched water above a fragipan. Since soil mottling is a natural and common process in saturated soil conditions it would seem reasonable that some evidence of soil mottling should have been observed in at least some of the soil profiles. The concern regarding the accurate identification of a SHWT is directly related to how well the proposed BMP will function. It is also important to acknowledge * New Jersey Stormwater Best Management Practices Manual Chapter 12: Soil Testing Criteria. March 2024. Page 23. https://dep.nj.gov/wp-content/uploads/stormwater/bmp/nj_swmp_12.pdf 6 Subsurface Investigation Report Subsurface Stormwater Management System West Orange, New Jersey for Garden Homes Short Hills, New Jersey Prepared by Sor Consulting Engineers, Inc. 98 Sand Park Road, Cedar Grove, NJ 07009, Report Number 23-C-17 May 23, 2023, Job No. 23-C-16. Page 5. Princeton Hydro, LLC Page | 5