STORMWATER

2010 - 2012:  Agricultural Water and Sediment Control Basins

                      Franklin County, VT 

Client:  Friends of Northern Lake Champlain

Friends of Northern Lake Champlain (FNLC) received grant funding to carry out a demonstration project on farms within the Missisquoi River basin to mitigate sediment and phosphorus runoff from crop fields. Prior to this project, water and sediment control basins (WASCOBS) had been installed in Quebec in the Pike River basin to reduce pollution to Lake Champlain, but the practices had not been tested in Vermont.

Fitzgerald Environmental Associates (FEA), in partnership with Agrilab Technologies (Brian Jerose), was hired by FNLC to identify sites in the Missisquoi watershed where critical source areas of phosphorus pollution are found and where WASCOBS may be suitable. Following outreach to farmers to discuss the siting and design concept for the WASCOB, FEA used a combination of LiDAR contour data, NRCS soils data, and field-based observations to develop rainfall-runoff models for each sub watershed using standard NRCS methods (i.e., TR-20 model). The WASCOBS were designed to treat the most frequent runoff events (24-hour storms up to 2 inches) and reduce the flow velocity in the structure to settle out fine sediments. The structures also include emergency outlets to safely pass larger storm events (i.e., 25-year storms) without exacerbating flooding or jeopardizing the structural integrity of the WASCOB.

2011 - 2012:  Highland Industrial Park Stormwater Design and Permitting

                     Winooski, VT

Client:  City of Winooski

Fitzgerald Environmental Associates (FEA), in collaboration with a subconsultant engineering firm, was retained by the City of Winooski to provide stormwater design and permitting services for a 34-acre, 10-lot industrial park on Tigan Street in Winooski, VT. The park represents 20% of the Morehouse Brook watershed and is a high-priority mitigation site to address biological impairment in the downstream channel. The site evaluation included a review of lot plans, incorporation of these plans into geographic information system (GIS) data, and field verification of man-made drainage features. Five low impact development stormwater practices (e.g., rooftop disconnects and bioretention systems) were designed and implemented at the lot-scale, and a large stormwater treatment system was designed, permitted per VTANR and USACE requirements, and constructed at the downgradient site which receives the park’s entire runoff.

The large stormwater system features three free-water surface wetlands and wet ponds in series to maximize treatment of the water quality volume and channel protection volume from the site. The stormwater projects were successfully constructed in 2012. FEA provided bid phase management, construction oversight, and erosion control inspection services during construction. 

2015 - 2016:  Colchester High School Stormwater Design

                      Colchester, VT   

Client:  Winooski Natural Resources Conservation District

Fitzgerald Environmental Associates (FEA) was hired by the Winooski Natural Resources Conservation District (WNRCD) to provide planning and design services to address stormwater runoff on the Colchester High School (CHS) grounds. The goal of the project was to map the existing stormwater infrastructure and provide a list of potential projects to improve stormwater treatment. FEA developed a HydroCAD stormwater model to estimate peak and total runoff to each stormwater collection area.

FEA developed stormwater management designs for five project areas. These were reviewed by WNRCD and CHS and three projects were selected for final design development. The designs included the installation of a bioretention basin to treat runoff from a one-acre student parking lot. 

2019 - 2020:  Route 30 Infiltration Basis Stormwater Design 

                       Poultney, VT

Client:  Poultney Mettowee Natural Resources Conservation District 

Fitzgerald Environmental Associates (FEA), in partnership with EcoSolutions LLC, was retained by the Poultney Mettowee Natural Resources Conservation District (PMNRCD) to provide stormwater design services for an area of chronic stormwater flooding with high stormwater phosphorus concentrations on Route 30 in Poultney, VT. The design entailed adding a catch basin to collect stormwater from Route 30 and send it across the street to provide stormwater treatment of an infiltration basin at the Town Offices. 

FEA performed a topographic survey of the site and hydraulic modeling of an adjacent tributary to the Poultney River. FEA and EcoSolutions prepared 100% design plans and oversaw construction of the project in the fall of 2019.

2020 - 2021:  Arlington School District Stormwater Design

                      Arlington, VT   

Client:  Bennington County Regional Commission

Fitzgerald Environmental, LLC (FEA), in partnership with Dufresne Group Consulting Engineers, was retained by the Bennington County Regional Commission (BCRC) to design four stormwater treatment practices on Battenkill Valley Supervisory Union property in Arlington, VT. The practices were identified as high priorities in a Town-wide Stormwater Master Plan (SWMP) completed by FEA in 2019. The school complex, which includes the Town’s K-12 schools and library, has an impervious surface of 7.7 acres and is anticipated to need a stormwater General Permit 3-9050 when the “3-acre site” requirement extends statewide in 2033.

FEA completed topographic survey, soil test pit observations, and infiltration tests to characterize site conditions for the proposed practices. FEA coordinated with school staff to identify underground utilities and maintenance considerations. The design team constructed hydrologic models to ensure the basins and outlet structures were appropriately sized. 

The design team conducted an alternatives analysis to select the best-fit treatment features for the site. The selected designs included a bioswale, gravel wetland, sand filter, and underground infiltration system, The final design plans are construction-ready and estimated to bring the schools a third of the way to complying with the General Permit 3-9050. 

2021 - 2022:  Mt. Norris Scout Reservation Stormwater Design and 3-Acre Permit

                      Eden, VT   

Client:  Lamoille County Conservation District

The Mt. Norris Scout Reservation is an 843-acre camp located in Eden, VT. The camp was identified by FEA in the 2019 Lake Eden Watershed Action Plan as a potential project, and the Vermont Dept. of Environmental Conservation (VTDEC) subsequently identified the camp as a “3-acre site” requiring a stormwater General Permit 3-9050. FEA, in partnership with Buermann Engineering, was hired by the Lamoille County Conservation District (LCCD) in 2021 to design two stormwater treatment practices at the camp.

FEA coordinated with Boy Scout volunteers to update impervious surface mapping and identify underground utilities. By refining the impervious surface mapping within the parcel, FEA demonstrated that the impervious area of the camp was approximately half of the value listed by VTDEC. 

Infiltration testing and test pit observations completed by FEA showed the soils around the camp’s large parking lot were suitable for infiltration treatment practices. FEA constructed hydrologic models to ensure the treatment practices were appropriately sized. The design team worked with camp volunteers to ensure that the proposed practices would be maintenance-friendly given their existing equipment and resources. 

The final designs would treat the full water quality volume (WQv) for nearly an acre of impervious surfaces. Preliminary mapping by FEA showed that most of the remaining treatment requirements could be met by improving disconnection practices for roads and buildings.

2008 - Present:  Indian Brook Watershed Stormwater Monitoring

                            Colchester / Essex, VT   

Client:  Lamoille County Planning Commission

Fitzgerald Environmental Associates (FEA) has completed a wide range of river corridor planning, hydraulic modeling, and hydrologic monitoring projects on Indian Brook in the Towns of Colchester and Essex, VT. FEA was first retained in 2008 by the Vermont River Management Program, operated through the VT Agency of Natural Resources (VTANR), to complete a river corridor planning project for Indian Brook. FEA tested the river corridor planning guide methodology for identifying potential restoration projects within the watershed. FEA documented and described 34 unique restoration projects, including removal of the Mill Pond Dam in 2020. 

FEA, in partnership with Stone Environmental, is currently operating a streamflow gaging station on the Brook downstream of the Susie Wilson Road Extension culvert. This station, established in 2022, is part of a flow monitoring effort required by the Total Maximum Daily Load (TMDL) document for the Indian Brook watershed. FEA is responsible for maintaining the streamflow monitoring station and for collecting discharge measurements to establish a stage/discharge rating curve. This high-resolution flow data will provide important baseline flow conditions and allow for accurate tracking of flow improvements over time as stormwater treatment best management practices are implemented within the watershed.

2012 - 2015:  Monitoring Farm Runoff and Agricultural Conservation Practices

                      Statewide VT   

Client:  Vermont Agency of Agriculture, Food and Markets

Agriculture has been identified as a major contributor of phosphorus (P) to Lake Champlain. Although federal and state programs, as well as landowners, have made unprecedented investments implementing agricultural best management practices (BMPs), these efforts have not yet yielded desired water quality results. There is an urgent need to evaluate and document the effectiveness of BMPs in the Lake Champlain Basin so that the most effective practices may be emphasized, and reasonable assurance may be provided that plans to achieve P Total Maximum Daily Load (TMDL) targets will be successful.

In 2012, the Vermont Agency of Agriculture, Food, and Markets (VAAFM), in cooperation with the USDA Natural Resources Conservation Service (NRCS), initiated an edge-of-field monitoring study to evaluate several innovative BMPs currently promoted by VAAFM and USDA. FEA, in partnership with Stone Environmental, was hired to conduct the study.

A paired watershed study design was used to test the effects of four different BMPs on event discharge and pollutant concentration and export in surface runoff from study fields. Six farms in the Lake Champlain Basin, from Franklin south to Pawlet, participated. Practices evaluated included: soil aeration on hay land prior to manure applications, cover cropping on silage corn, reduced tillage and manure injection on cornland, and a water and sediment control basin treating runoff from a cornfield.

Discharge, rainfall, and air temperature were measured continuously at each station. Event composite samples were collected using a flow-paced autosampler. The telemetry and telecommand capabilities of the monitoring systems enabled efficient management of sampling teams, instruments, and data.

2015 - 2020:  Streamflow and Precipitation Monitoring for MS4 Communities

                       Chittenden County / St. Albans, VT   

Client:  Vermont Department of Environmental Conservation

In accordance with Municipal Separate Storm Sewer Systems (MS4) general permit requirements, certain towns and entities are required to implement and fund a flow and precipitation monitoring program in their impaired watersheds. In 2015, Fitzgerald Environmental Associates (FEA), in partnership with Stone Environmental, was contracted by the VT Department of Environmental Conservation to conduct flow and precipitation monitoring in 11 impaired watersheds in Chittenden County and St. Albans, VT.

Pressure transducers, staff gages, and rain buckets were installed by the Project Team in the summer and fall of 2016 and remained in operation until 2020. FEA’s work on the project involved detailed monitoring, station maintenance, streamflow measurements, rating curve development, and data analysis. Discharge and rainfall were measured continuously at each station. All monitoring sites had telemetry and telecommand capabilities.

2013 - 2017:  South Burlington City-Wide Stormwater Analysis 

                      South Burlington, VT   

Client:  South Burlington Public Works Department

The South Burlington Stormwater Utility (SBSWU), a subdivision of the South Burlington Public Works Department, has been upgrading and installing new stormwater best management practices (BMPs) throughout the city since 2005. In early 2013, the SBSWU sought to develop city-wide estimates of stormwater runoff volumes and pollutant loads for the period from 2003 to 2012. The purpose of this analysis was to 1) estimate runoff volumes and pollutant loads at the City-scale since the inception of the SBSWU; 2) estimate how the treatment provided by the BMPs and maintained by SBSWU compares with the volumes and loads at the City-scale; and 3) track SBSWU progress in treating stormwater over time. SBPWD hired Fitzgerald Environmental Associates (FEA) to develop the methods and data to address these questions. Due to the complexity of estimating peak flow rates in multiple sub watersheds in South Burlington, FEA developed a volumetric-based approach for estimating stormwater treatment and pollutant load removal.

2015 - 2018:  South Burlington Watershed Planning Projects 

                      South Burlington, VT   

Client:  South Burlington Public Works Department

Fitzgerald Environmental Associates (FEA) was selected to provide watershed planning technical services, and complete several water quality sampling and monitoring projects, for the South Burlington Public Works Department (SBPWD) from 2015 through June 2018. 

FEA completed the 2015 sampling and reporting for the Potash Brook water quality monitoring plan. The plan was developed by Pioneer Environmental in 2001 and sampling efforts were previously completed by VHB in 2004-07, 2009, and 2011. FEA collected baseflow and storm event samples, completed macroinvertebrate community assessments in partnership with the Vermont Dept. of Environmental Conservation (VTDEC), and characterized stream geomorphic features at monitoring stations located throughout the Potash Brook watershed. A report was developed to summarize the 2015 data analysis and comparisons with previously collected data to check for water quality trends and potential improvements following ongoing stormwater treatment implementation within the watershed. 

FEA installed and operated a streamflow and water quality monitoring station on Potash Brook in 2015. The primary goal of this project was to quantify total phosphorus and total suspended sediment transport during storm events, and to test the strength of the relationship between turbidity, phosphorus, and sediment. The results indicated that turbidity was an effective tool for estimating phosphorus and sediment transport, leading to the recommendation that SBPWD purchase a continuous turbidity sensor for high-resolution monitoring in Potash Brook. This project was a precursor to the Potash Brook In-Situ Turbidity Sensor monitoring that is currently underway and being managed by FEA and Stone Environmental.

FEA was contracted by the SBPWD to operate SIGMA autosamplers at the inlet and outlet of two stormwater treatment ponds in the Oak Creek neighborhood. The primary goal of the project was to assess the performance of each pond and to quantify reductions in phosphorus and sediment reaching Tributary 7 to Potash Brook. Water levels in the pond were also monitored and a spreadsheet was developed to calculate inflow/outflow rates based on the change in pond level. 

2016 - 2018:  Castleton Headwaters Stormwater Master Plan 

                      Castleton, VT   

Client:  Poultney Mettowee Natural Resources Conservation District

Fitzgerald Environmental Associates (FEA) was retained by the Poultney Mettowee Natural Resource Conservation District (PMNRCD) to complete a Stormwater Master Plan (SWMP) for the Castleton River headwaters watershed located in the Towns of Castleton and West Rutland, VT. The project was a continuation of the Lake Bomoseen SWMP which FEA completed for PMNRCD in 2016. The plan follows the Vermont Agency of Natural Resources hybrid Template 3.a.b, including a watershed-scale approach with traditional stormwater management in the more developed areas, and a regional-rural approach with a focus on rural roads and neighborhoods.

A total of 75 stormwater problem areas were identified during field surveys and tours with PMNRCD staff. The projects were listed in a master spreadsheet that included a series of prioritization metrics. A total of 12 projects were selected for restoration designs, and five projects were selected for 30% conceptual designs. Four of the restoration designs and four of the 30% concept designs were developed for parcels that will fall under the 3-acre impervious rule. PMNRCD secured funding and retained FEA to develop 100% designs and oversee the implementation of a stormwater infiltration feature at the Castleton Town transfer station, which is part of a large municipal parcel that will be subject to the 3-acre rule. 

2016 - 2022:  Chittenden County Road Erosion Prioritization and Conceptual Designs 

                      Chittenden County, VT   

Client:  Chittenden County Regional Planning Commission

Fitzgerald Environmental Associates (FEA), in partnership with Milone & MacBroom, was retained by the Chittenden County Regional Planning Commission (CCRPC) to develop a road erosion prioritization methodology using inventory data collected in 8 towns in the county. The project objective was to assist CCRPC and the towns in ranking road segments with the greatest impact on water quality to meet the requirements of the forthcoming Municipal Roads General Permit (MRGP).

FEA performed a quality control analysis of the REI data, met with the road foremen and other key staff in each town, developed a prioritization method with REI variables and GIS-derived road slope (see figure below), and completed field reviews of over 100 road segments to calibrate the methods. The project was ongoing through 2022 with additional field mapping and surveys to support development of conceptual designs for 24 priority sites. The designs have been used to support Better Roads grant applications to fund erosion mitigation projects on high priority road segments, all of which were funded by the Vermont Agency of Transportation.

2018 - Present:  Milton Stormwater Master Plan, Design and Implementation 

                           Milton, VT   

Client:  Chittenden County Regional Planning Commission

Fitzgerald Environmental Associates (FEA) was retained by the Chittenden County Regional Planning Commission (CCRPC) to complete a Stormwater Master Plan (SWMP) for the Town of Milton. The project was funded through the Vermont Agency of Natural Resources (VTANR) Clean Water Initiative Program and Town funds. The initial process began with the identification of stormwater problem areas using a desktop exercise, aerial imagery to scan the watershed, NRCS soils data analysis, Town stormwater infrastructure mapping, contour data, and road erosion inventory results from geographical information system (GIS) data. Potential project areas were identified and mapped for review during site visits.  Specific areas were identified by the Town, CCRPC, and VTANR as the focus of the SWMP effort.  FEA identified 65 stormwater problem areas during field surveys and tours with the Town Highway Department. The projects were prioritized based on the “Unified Scoring Prioritization” method developed by the Vermont Dept. of Environmental Conservation (VTDEC). This method required more detailed calculations to estimate the $/pound of phosphorus removed for each proposed project. Problem area summary sheets were developed to describe the top 30 projects in greater detail. Fifteen of these projects were selected for development of 30% conceptual designs, with many projects requiring additional field surveys and GPS mapping.

As part of this project, FEA worked with the Town to develop preliminary calculations for the Town’s Phosphorus Control Plan (PCP), as required by their MS4 permit. FEA developed a preliminary phosphorus baseload and required phosphorus reductions for the municipally owned and controlled properties. Analysis of non-structural treatment practices (street sweeping and catch basin cleaning) were included. The concept designs developed for the SWMP included estimates of Municipal phosphorus removal for each of the proposed treatment practices. Based on our initial calculations, implementation of 14 of the conceptual design projects would address approximately 11% of the Town’s required phosphorus reductions. 

FEA,  in partnership with EcoSolutions LLC, have advanced three high-priority stormwater practices to final design for implementation in 2022 and beyond.