Stephens Environmental Consulting, Inc.'s Sample Projects

Hertz Maintenance Facility/U.S. Airways: SECI performed environmental consulting services for this client, these services include: (1) Preparation of specifications/work protocols and procedures for asbestos abatement, soil and groundwater remediation, oil water separator and reclamation pit cleaning and decommissioning and site specific safety plan at former Hertz Facility in preparation for new U.S. Airways hangar. (2) Performed an extensive hydrogeologic investigation to fully characterize the extent and concentrations of petroleum contamination at a leaking underground storage tank (UST) site. The investigation included 52 geoprobe soil borings, field screening of >200 samples for volatile organic compounds, and the laboratory analysis of 46 samples for PaDEP Act 2 list compounds for leaded/unleaded gasoline and diesel fuels. (3) Provided Remedial Design (RD) and Remedial Action Oversight (RAO) during the removal of 12,500 tons of petroleum impacted soil and nearby 1 million gallons of petroleum contaminated groundwater. Supervised the design of the field dewatering well points, storage, filtration, and discharge facilities for water. Obtained permits and conducted post-excavation and sewer discharge sampling, also supervised remedial contractor. Reports are in progress. (4) To provide post-remedial guidance to Construction Manager during subsurface utility construction in remediation area.

Union Hospital: Conducted an extensive Phase 2 ESA consisting of a thorough regulatory records review and subsurface investigation for a property in an environmentally degraded area of Cecil County, Maryland. Past site use included a dry cleaner, textile manufacturer and auto repair shop. Adjoining facilities included two bulk petroleum storage plants and an abandoned automobile parts repair (former textile mill) facility with known chlorinated solvent contamination extending onto the subject property. SECI identified and characterized low levels for chlorinated solvents in groundwater entering the subject property from the auto parts repair facility. We identified previously unrecognized petroleum contamination extending onto the property from adjoining former fuel depots. SECI also proved that no contamination identified originated on the property and no human health risk was posed by the identified contamination, allowing the transaction to proceed.

Service Station PaDEP Act 2 Closure: Phase 1 ESA for an existing service station and former gasoline station. Phase 2 ESA included subsurface soil and groundwater sampling and testing to determine the extent and concentrations of petroleum substances released from various UST's and hydraulic fluid reservoirs and floor drains. Prepared Act 2 Final Health Standards Report and received closure for all identified concerns, using PaDEP Residential Statewide under Act 2.

Poultry Plant Hydrogeologic Evaluation: SECI performed an extensive Hydrogeologic Investigation to assist a major poultry plant with expansion of their existing permitted groundwater usage from 1 million to 2 million gallons per day. Testing required by Maryland Department of the Environment (MDE) Water Management Agency (WMA) included a 24 hour simulated Pretest Shutdown with 6 hour Step Drawdown Test and a 24 hour constant pumping Pump Test followed by a 12 hour Recovery Test with a 12 hour Pre-test Shutdown.

The project was complicated by the operations of the plant and multiple wells in the well field, where only the weekends were available for testing. The project was further complicated by the lack of spatial information on the wells, the superposition of public water supply withdrawals and other factors. SECI’s testing and development of an accurate well field history demonstrated the aquifer can sustain the required withdrawal without significant impacts to neighboring domestic or public water supply wells.

Ford Property WRPA Subsurface Evaluation: Subsurface investigation and geotechnical investigation of a 2 acre proposed subdivision lot in the sinkhole-prone Hockessin Valley of New Castle County, Delaware. The investigation included four standard penetration test exploration borings along a section through the proposed on-site structures; soils laboratory testing, and drainage and foundation recommendations for the proposed structures.

The purpose of the evaluation, as required by New Castle County Code, was to determine the potential risk of subsidence and sinkhole development, and to recommend appropriate foundations for the proposed structures.

Lot 15 Sandy Brae Industrial Park: SECI performed a subsurface evaluation to assess the potential feasibility for an on-site infiltration practice for a proposed expansion of an existing industrial facility in the City of Newark. The proposed expansion prohibited the use of a surface pond for stormwater quality enhancement. The subsurface evaluation included six exploratory test pits, six hand auger soil borings, soils laboratory analysis and classification of ten selected soil samples, and three field single ring infiltrometer test to directly measure the field permeability of targeted favorable soils.SECI subsequently provided all drainage analysis, grading and drainage design and the design of sand filter water quality enhancement devices to filter runoff from pavements. An infiltration practice design was provided for disposal of 50% of the filtered pavement runoff from the site.SECI prepared all required construction improvement plans for the site as required by the City of Newark, which included a Drainage, Lines and Grades Plan, a Sediment and Stormwater Management Plan, and a Standard Details Sheet. The submission was approved for construction by the City of Newark with no comments or requests for changes.SECI subsequently performed a forensic retaining wall analysis and design, supervised the installation of the stormwater quality management system, and performed an "As-Built" survey of the completed project.

Commercial Site Phase 1 & 2 ESA: SECI performed a Phase 1 ESA of a 2.75 acre commercial property in New Castle County, Delaware and discovered historic indications of past land use as a gasoline station. No surficial indications of this past land use were apparent from the reconnaissance. Information gathered as part of the historical research was used to focus a Phase 2 subsurface investigation to identify the former UST area within the former location of the gas station, and determine the presence or absence of released petroleum. A significant release was discovered, and the client was able to table the purchase until the owner effects satisfactory remediation of the site.

Canada Dry Plant Brownfield Environmental Services: SECI performed a Phase 1 ESA for a confidential client interested in purchasing a 6 acre, 120,000 square foot bottling facility. Identified issues included 5 removed USTs, two with significant releases, a mechanic shop with surface-to-subsurface releases of petroleum from multiple ASTs, large PCB transformers, asbestos, lead paint, etc. SECI subsequently performed an extensive Phase 2 ESA to evaluate these issues and prepare cost estimates prior to purchase.

SECI later supervised the asbestos abatement and prepared follow-up documentation for the client, PIDA & PEDFA. The Phase 1, Phase 2 ESA and Asbestos Abatement Report received high praise from the client, the client's environmental counsel, the realtor, the owner's consultant and the chief environmental auditor for Core States Bank.

Bellecor Drive ESA, UST Remediation: SECI completed a Phase 1 ESA and oversight of UST and Drum Removal for a confidential client/property owner as a prerequisite to the pending sale. One of the two tanks had leaked, and SECI moved swiftly to "surgically" remove approximately 40 tons of contaminated soil for offsite thermal desorption. The State provided regulatory closure based on SECI’s post-excavation sample analytic results. SECI’s quick and effective response allowed the client to move to settlement on schedule.

Junkyard Phase 1 & Phase 2 ESA: SECI performed a Phase 1 and Phase 2 Environmental Site Assessment of an approximately 10 acre site with a historic junkyard. The Phase 2 included the installation, development and sampling of 3 groundwater monitoring wells, and sampling of surficial soils. SECI was able to demonstrate through sampling and laboratory analysis that groundwater was not impacted and substances of concern, including Petroleum Hydrocarbons, lead and PCBs, were confined to an area of distinctly discolored, debris-laden soil covering an area 200’ x 375’ and varying from 1" to 5" thick. The underlying undiscolored soils and groundwater were not impacted.

SECI recommended redevelopment of the site following remediation to residential standards through the VCP process. The findings of the evaluation are anticipated to facilitate the sale of the property for development.

Churchville Citgo: This project included a quarterly monitoring of five monitor wells and three drinking water wells impacted by BTEX, TPH and MTBE. SECI discovered mistakes by the previous consultant that negatively impacted the client, including: incorrect monitor well top-of-casing elevations, improperly developed wells, improperly labeled (switched) wells and damaged wells. Resolution of these issues demonstrated that the plume was localized onsite, not moving offsite as suggested by the previous consultant.

Historic Inn: SECI performed a Phase 1 ESA and building material surveys of an historic inn in Kent County Delaware. A number of issues were identified, including underground storage tanks, friable asbestos containing materials, lead paint and a small petroleum release inside the building. SECI was able to provide a range of potential clean-up costs for the identified issues to allow the buyer to budget for those environmental considerations prior to settlement. SECI assisted the developer and developer's lender with closure of outstanding issues, prior to approval of a construction loan.

Service Center: SECI performed a hydrogeologic investigation of a leaking underground storage tank (LUST) site in Kent County, Delaware. The approach to the investigation allowed the client to realize considerable savings in potential investigation costs (by not installing 4 monitor wells, as proposed by others), and focused the required remediation on the most seriously affected soils. SECI’s Corrective Action Work Plan was approved by DNREC-UST. The Corrective Action, which consisted of the over-excavation of approximately 450 cubic yards of petroleum impacted soils for ex-situ biomediation was completed in only a few days.

Post excavation sidewall and bottom grab samples demonstrated that the cleanup goals were attained. SECI’s bio-remediation approach reduced petroleum concentrations to non-detectable levels in one year. The DNREC-UST Branch closed the LUST based on attainment of the applicable cleanup standards.

Millsboro Property: SECI was retained by a private property owner to perform a Hydrogeologic Investigation of a site in Millsboro, Delaware. The property had been operated as a gasoline station during the 1970's, and the 5 USTs were improperly abandoned, prior to the State's Adoption of regulations governing UST removal/abandonment. The client had recently purchased the property. SECI prepared a work plan for the first phase of the Hydrogeologic Investigation which was approved by DNREC-UST.

SECI executed the Phase 1 HI soil exploration effort, surveyed the property and integrated the results the UST removal contractor's closure sampling analytic results into the Progress Report. SECI determined that contamination above Department Action Levels extended beyond the UST removal excavations and proposed Work Plans for additional over-excavation and a groundwater evaluation.

The Interim Remedial Action and Hydrologic Investigation included over-excavation and bioremediation of 1000 tons of contaminated soil. SECI closed the site as a consultant to the state under their "First Fund" cleanup assistance program.

Red Mill Nursery: Provided wetland mitigation design for a proposed commercial development at the former location of a wetland plant nursery. The design involved the creation of approximately one acre of diverse wetland habitats in association and combination with stream relocation and storm water management. The project was approved without comment by the Parks Department, and the Army Corps of Engineers, Philadelphia District. The reviewer for the ACOE commented that the mitigation design was "one of the best I'd ever seen", and "the client got his monies worth".

Monitoring was terminated by the Corps the second year because the vegetation established quickly.