Water Quality Monitoring, Interstate 84 Improvements - Waterbury, CT

GZA worked with the Connecticut Department of Transportation (CT DOT) to prepare an Environmental Impact Statement for the 32-mile Interstate 84 Corridor from Waterbury, CT to the New York State Line in conformance with NEPA and CEPA requirements.  GZA interfaced directly with DEEP, USACE, EPA and FWS in preparing Least Environmentally Damaging Practicable Alternative (LEDPA) documentation and a draft Section 404/401 permit application.

GZA managed and lead a scientific team in wetland and stream delineation, evaluation, impact mitigation design, and permitting for a 3.5 mile section of I-84 through portions of Waterbury and Cheshire, CT, paralleling waterbodies and wetlands along virtually its entire length. GZA also was responsible for permitting the project under State and Federal regulations.

As part of the permitting process for the project, CT DOT requested a water quality monitoring program be established based on potential water quality concerns associated with the project including changes in stormwater pollutant loadings from increased impervious area associated with travel lane additions.  CT DOT selected parameters to be monitored and established program timelines and requested grab sampling during storm events at seven locations in the project area.  Sampling focused on pollutants specific to the area, namely sediment, deicing agents, and bacteria (as the main stream in the area was impaired for bacteria). 

A water quality monitoring program was established to provide a baseline of existing conditions relative to water quality in the project area.  Data was collected from November 2012 to June 2013 to cover a period which would include the salt application season, as well as pre- and post-salting periods.  GZA prepared a Work Plan for CT DOT approval for data collection and quality control procedures which identified sampling locations, onsite measurements, sample collection, quality control sampling, and analytical testing methods.  Grab samples were collected by GZA once per week for the duration of the study period and samples analyzed in the field for temperature, dissolved oxygen, specific conductance, and pH, with analytical testing for chloride, total suspended solids, turbidity, fecal coliform, and E. coli.  Visual observations of flow rate, snow depth, and snowmelt were also collected.  Sample data was analyzed and a summary report prepared at the end of study period, documenting the study process and results.