South Kearny, New Jersey

Project at a Glance:

• Remedial measures were required for a portion of this site pursuant to an Administrative Consent Order (ACO) executed by NJDEP. The remedial measure selected consists of surface asphalt treatment over chromite ore processing residue soils covering approximately 3 acres of the approximate 8-acre site.
• Whitman prepared the proposed stormwater management system design drawings for review and approvals of the township engineer and the local Municipal Utilities Authority (MUA). The design package included design drawings detailing the existing and proposed drainage areas, construction details and TR-55 calculations for determining design runoff conditions.
• The design runoff was calculated based on the proposed area of the trucking facility planned for capping with asphalt of approximately 5.5 acres of existing gravel surfaces.

Project History

Whitman was contacted by the trucking facility to perform an evaluation of the existing stormwater sewer system and design a new system to conform to the future improvements planned at the site. The majority of the site is currently unpaved gravel with three (3) buildings located on the approximate eight (8) acre parcel used as trucking terminals. The site is currently bound on three sides by public streets and the fourth side by an elevated skyway overpass. The proposed improvements to the site consist of an asphalt pavement cap across all unpaved areas.

Design

A property boundary and topographic survey was performed by a New Jersey Licensed Surveyor, for design purposes with elevation contours at one (1) foot intervals in accordance with United States Coast and Geodetic Vertical Datum.

Analysis of the existing site drainage and proposed site drainage was performed to determine the total volume of existing and proposed storm water runoff generated during the 25-year storm event. The storm water runoff volume was calculated utilizing USDA Natural Resources Conservation Service (NRCS) Technical Release No. 55.

Because the entire site is capped with asphalt pavement, the proposed design storm-water runoff significantly increased, thereby requiring increased capacity of the on-site sewer system. Due to lack of space for construction of an aboveground storage detention basin, an underground system consisting of a series of interconnected reinforced pipes is planned.

Site plan of 8-acre trucking facility illustrating existing stormwater drainage areas.

Off-site collection inlet along public right-of-way.

Storm sewer manhole near trucking terminal stone for new SDR-35 PVC sanitary sewer pipe.