City of Ansonia DPW WWTP

Service: Engineering, Investigation, Consulting
Project: City of Ansonia DPW WWTP Expansion
Client: City of Ansonia and CDM (Separate contracts as prime and subcontractor)
Site Location: Ansonia, CT
Period of Performance: 2007 – 2008

H&S performed a hazardous materials investigation, Phase II Site Assessment, asbestos and lead paint survey, off-site disposal characterization, construction management, and reporting in support of the construction of a modernized and expanded waste water treatment facility (WWTF) for the City of Ansonia, Connecticut.

We initiated our contract to City of Ansonia as a subcontractor to CDM. Outstanding subcontractor performance resulted in the City of Ansonia requesting H&S to perform work directly for City, completing the site investigation of the sludge burial area.
H&S performed a limited subsurface investigation to evaluate subsurface soil and groundwater at an uncontrolled buried sludge/compost disposal area. Our geologist delineated the extent of the burial area to allow excavation and removal of hazardous materials without stockpiling in an area with limited storage space.

Using the direct push soil sampling technique we minimized cost associated with sampling equipment, excess sample materials requiring disposal as IDW, and labor and material to backfill the soil borings compared to cost using a hollow stem auger. Two of the soil borings were completed as monitoring wells to evaluate the groundwater for the presence of contaminants. Eight soil samples and one groundwater sample were submitted for laboratory analyses. Based on the initial analytical results, we performed an extensive second phase of sampling, further delineating the extent of the sludge contaminants.

In total, we collected over 100 soil and sludge samples to determine the extent of contaminants. Samples were analyzed for metals, volatiles, semi volatiles, CT ETPH, and PCBs using EPA SW846 methodologies. Proper chemical QC was ensured through appropriate sample collection procedures, chain of custody implementation, storage and transportation, and review of data results. All samples were analyzed by a State of Connecticut certified laboratory, ensuring laboratory QA and regulatory compliance.

H&S performed a hazardous building materials survey of four buildings with basements at the WWTF. We identified asbestos-containing materials (ACMs), lead-based paints (LBPs) and mercury containing fluorescent lights and thermostats/bulbs. To expedite the investigation and minimize analytical costs we used an XRF detector to perform field surveys for lead paint. Bulk ACM samples were collected for analysis by Polarized Light Microscopy and bulk LBP chip samples were analyzed based on XRF field survey results. We prepared a comprehensive data report with recommendations to the City of Ansonia to assist with decisions for their clean up objectives.

After completion of the investigations and assessments, H&S prepared comprehensive technical plans and specifications for the abatement of asbestos and lead paint materials. The plans were structured to achieve safe abatement in compliance with Federal EPA, AHERA, OSHA, DOT, National Institute of Building Sciences (NIBS) standards, and the state of Connecticut’s regulations. We ensured the specification sections were compliant with work practices and post-abatement clearance requirements of the EPA AHERA regulations and OSHA regulations.

  • Effective investigation strategies saved $20,000 through technical recommendations in drilling methodologies and reduced sampling areas