Our experience is best illustrated through representative projects completed by the firm. Brief summaries of several projects are provided.

MTBE - Hampton Bays, Suffolk County, NY
 
After the Suffolk County Department of Health Services detected 54,000 ug/L of MTBE in a Hampton Bays well, data gathered in an accelerated site assessment procedure (ASAP) by a New York State Department of Environmental Conservation (NYSDEC) contractor was used to guide the installation of a large monitoring network to delineate the contamination. The ASAP suggested that a mixed fuel oxygenate plume including MTBE and its degradation product TBA extended over 2,500 feet towards a sensitive surface water receptor, Tiana Bay. SSP&A was retained to model groundwater flow and the migration of MTBE and TBA to evaluate potential impacts on Tiana Bay and support the design and management of a pump-and-treat (P&T) remedy.  MORE >

Interstate Water Compact - Republican River Basin
 
In November 1999, the U.S. Supreme Court appointed a Special Master to oversee resolution of a dispute regarding allocation of water from the Republican River and allegations that Nebraska had violated the Republican River Compact. The Compact, signed in 1943 by the three basin States of Kansas, Colorado and Nebraska, allocates the water supply of the Republican River, with the total allocation given to each State derived from listed tributaries, and for Nebraska and Kansas, from the main stem of the Republican River. SSP&A was retained by the State of Kansas to provide technical support in quantifying the nature and magnitude of streamflow accretions and depletions from the ground water system in the Republican River Basin.  MORE >

Hyde Park Landfill Groundwater Model, Niagara Falls, NY
 
At this site where 20,000 tons of chlorinated DNAPLs were disposed, SSP&A reviewed regional and site data to develop a model of groundwater flow in the fractured rock of the Lockport Group. SSP&A constructed, calibrated, and applied the model to the Occidental Chemical Corporation Hyde Park Landfill site. SSP&A’s role evolved to include all aspects of data collection work plans and data review. SSP&A’s approach was to use an equivalent porous medium (EPM) approach using MODFLOW to simulate groundwater flow. SSP&A modified an existing regional model developed by the USGS by refining the discretization in the vicinity of the site and incorporating detailed site information.  MORE >

Bay Road Superfund Site East Palo Alto, California
 
Since 1984, S.S. Papadopulos & Associates has directed the investigation and remediation of the 1990 Bay Road Superfund site. Arsenic contamination has affected soil and shallow groundwater in the 20-acre site area adjacent to San Francisco Bay, including wetland areas having both tidal and non-tidal marshes. SSP&A has conducted extensive hydrologic investigations and modeling at the site in both the shallow and deep groundwater zones to (1) assess the impacts of historic disposal practices, and (2) estimate the extent of further migration over time at the site.  MORE >

Middle Rio Grande Water Supply Study, New Mexico
 
This study integrated vast quantities of existing data, models and investigations conducted over the past 100 years over a 150-mile reach of the Rio Grande to obtain a probabilistic description of the conjunctive-use groundwater and surface-water supply. Using historic data, a water budget was developed for the linked groundwater/surface-water system. To characterize the water budget elements and their variability, descriptive statistics and probability density functions were developed for each water budget inflow and outflow term using data recorded over a 50-year period. Groundwater inflow/outflow to the river system was characterized through MODFLOW simulation. Monte Carlo simulation of the river system water budget was conducted to characterize the probabilistic nature of the overall water supply and likelihood of meeting Rio Grande Compact obligations under several potential future development conditions.  MORE >