Green Infrastructure Design
Many localities faces a significant challenge related to stormwater runoff management, including nuisance flooding in low-lying areas during storm events as well as meeting specific permitted goals for CSO and MS4 considerations. The installation of green infrastructure is an important redevelopment strategy which can help with runoff reduction and provide attenuated runoff outcomes to help mitigate the effects of storm events. As well as being a strategy to support CSO reduction and MS4 goals, green infrastructure also supports “Complete Streets” compliance and can be incorporated in a variety of styles to accommodate a range of topologies on streetscape and transportation projects. Green infrastructure BMPs can serve as small-scale stormwater management facilities that use vegetation, soils and natural processes to detain and retain stormwater. They can be strategically integrated into the urban landscape, reduce surface runoff and limit flood volume that contributes to combined sewer overflows while enhancing the urban aesthetic of the street.
Our portfolio of green infrastructure work includes:
- Citywide GI program management
- Park drainage plans
- Bioswale design and construction
Provided strategic support to the Bureau of Environmental Planning and Assessment (BEPA) and the Office of Green Infrastructure (OGI) in various tasks pertinent to GI planning and implementation. Specifically, the calculation of managed impervious areas based on projects included in the web-based GI projects database, determination of feasible levels of GI penetration in various WWTP service areas and prioritization of subwatersheds where OGI can focus the design efforts on, early evaluation of asset management tools that led to the visioning for PTAMS, modeling of retention and detention GI practices in InfoWorks CS to evaluate the performance of GI penetration rates on a citywide basis, performance evaluation of GI at site and neighborhood scales, provision of guidance on research and development needs, and support on public outreach through steering committee initiatives.
Coastal Resiliency Planning
Boomi is helping coastal communities keep pace with rising sea levels and more severe storm surges. As these issues have move to the forefront of the climate change adaptation conversation, we are supporting municipal governments in their efforts to both plan for future storms and create sustainable infrastructure that will protect and improve communities in the short term. Our services for coastal resiliency planning and design include:
- Modeling building and district-scale flood barrier systems
- Conducting interior drainage studies for low-lying communities
- Setting city-wide coastal design criteria for storm surge and rainfall
RISE:NYC is part of a Disaster Recovery Block Grant program funded by the U.S. Department of Housing and Urban Development, and administered by the NYC Economic Development Corporation (EDC). It is aimed at helping small business owners who were impacted by Superstorm Sandy to mitigate future flood damage through the identification of vulnerable building infrastructure, customized online weather forecasting, and recommendations for flood-proofing technologies.
Boomi led the development of a high-resolution flood risk characterization around each business location. Models were constructed by combining high-resolution ground elevation data with spatial data covering building footprints and local sewer infrastructure. This model was then subjected to 90 adverse condition scenarios covering rainfall events ranging from 3-month to 100-year storms, and tidal conditions ranging from yearly averages to those resembling Superstorm Sandy. The flood depths observed in each model served as the basis for an online flood risk portal that will send notifications to business owners in the case of forecasted rainfall and tidal conditions that have the potential to cause flooding impacts.
Boomi is also assisting in field auditing efforts, which involves walk-throughs of each small business to identify vulnerable infrastructure that could be affected by future flooding and potential mitigation strategies such as the installation of deployable flood walls, sealing building envelopes, or relocation of critical infrastructure. We will assist with selection and design of flood mitigation elements for a select number of businesses that will be used as case studies for future flood-proofing technology implementation.
With costs mounting for addressing issues such as deteriorating infrastructure, resilancy planning and regulatory compliance, governments are tasked with critical decisions that will maximize benefits versus expenditures. Environmental Analytics is a field where accumulated sampling leveraged along with geo-data is used to make informed decisions to address critical issues facing a government. Whether it is with setting up data gathering programs for air quality and water analytics or making sense of a wealth of data already on-hand. Boomi can help.
Since the creation of modern water quality standards with the Clean Water and Safe Drinking Water Acts, sewer system compliance has, and continues to be an evolving field that requires local knowledge of system conditions and government institutions. Boomi’s healthy relationship with federal, state, and local environmental agencies, along with our design and planning work for municipalities in New York, New Jersey, and Pennsylvania, have given us a deep understanding of the operational capacities of the sewer systems in this region, and the regulatory gaps that must be closed in the near future. Whether it be sewer long term control planning or environmental liability studies for Superfund sites, we can help you meet your water quality compliance needs.
The City of New York has been pursuing LTCP efforts since 1980s to mitigate the impacts of CSOs and stormwater on its confined and open waterbodies. The key components of these plans are holistic solutions to the challenges pertinent to compliance with New York State water quality standards, namely the development of affordable grey and green infrastructure improvements.
Boomi’s staff have worked extensively outside and within DEP on major components of LTCPs since 2004, including sewer system characterization, modeling evaluations, drainage analyses, and alternatives evaluation. We also have supported on related components including GIS mapping, field investigations, regulatory program support and technology transfer to the DEP staff for ongoing maintenance/use of the sewer system models. We played a pivotal role in the recalibration of InfoWorks (IW) models in 2009-2012, introducing innovative calibration and validation procedures to enhance models’ reliability and robustness. We also developed innovative tools to estimate pollutant loads based on sanitary and stormwater splits in CSOs.
The Skippack Creek watershed is approximately 55.5 square miles and encompasses drainage areas from twelve (12) municipalities. As is already known, the State’s Department of Environmental Protection (PADEP) has required these twelve MS4 communities, with impaired waterways, to outline steps that must be taken to reduce sediment load currently discharging to (and from) the Skippack Creek by way of TMDL Plans. For the Skippack Creek, DEP/EPA is requiring a reduction of 18% or 3,463,873 lbs/yr cumulatively, by the six municipalities participating in this program. Pollution load reduction on this scale presents a significant challenge to individual municipalities who may look to achieve these numbers on their own. As the professionals working towards this goal can attest, the path to addressing these reduction numbers individually have proven difficult and cost prohibitive. Consequently, the purpose of this study was to evaluate the potential of planning on a “regional” or watershed basis versus on a “project” (municipal) basis. In looking at the overall watershed, this study sought to evaluate the potential for a greater magnitude of sediment reduction by planning collectively, and on a much larger-scale. Another aspect of this evaluation was to identify compliance with these permit goals in a more cost-effective way. After reviewing a large cross-section of potential programs, the field of projects was narrowed down to six (6) programs which, if executed, could provide approximately 8.1% of the required 10% reduction needed for the first 5-yr permit term. Considering the cumulative influence of “past” projects already constructed by the municipalities, the current planned level of sediment reduction is estimated to be close to 9%. A shortfall estimated to be around 150,000 lbs/yr still remains to meet the required goals for permit cycle 1, if this program was to be executed, with the remaining 8% (18%, cumulatively) being the responsibility of the second permit term (second 5-year cycle).
Urban Watershed Management
As municipalities and water utilities deal with the growing needs to bring their sewer systems into compliance with State and Federal environmental regulations, the need for modern approaches to modeling urban water and sewersheds. We assist our clients with a broader watershed-based approach to pollution reductions from combined sewer overflows, sanitary sewer overflows, stormwater from urban areas, and wastewater discharges, and provide multi-objective decision-making frameworks to select projects that maximize environmental and social returns-on-investment, in addition to being cost-effective.
The Bethlehem Township Municipal Authority (BTMA) maintains a separated sewer system that covers 13,000 acres of the Lehigh Valley, discharging into 4 tributaries of the Delaware River (Lehigh River, Nancy Run, Monocacy Creek, and Bushkill Creek). Boomi was retained by BTMA to provide stormwater engineering services, including the development of a Township-wide stormwater model, and decision support for infrastructure improvements aimed at reducing nuisance flooding.
We worked closely with BTMA facilities management staff to compile sewer infrastructure spatial data from across the township and adjacent municipalities, and digitize sewer assets from as-built drawings. We then performed a comprehensive gaps analysis of the existing data to coordinate field inspections of unidentified assets. A online GIS database was constructed to host these old and new data, from which a one-dimensional ICM Infoworks model could be developed.
Future model improvements will include the delineation of stormwater detention basins, the inclusion of riverine cross sections along critical sections of the receiving tributaries, and the construction of a two-dimensional surface to allow for surface flooding impacts to be modelled accurately.
The Perth Amboy Revitalization Agency (PARA) is planning a comprehensive revitalization of a 6-acre property running along 2nd Street and ending at the Raritan River, converting an undeveloped lot into a thriving community park. Along with amenities such as a spray park, skate park, amphitheater, and a coastal meadow, the park will also feature an array of green infrastructure installations designed to manage stormwater runoff from impervious surfaces, and divert all runoff away from the combined sewer system during a 10-year storm.
Boomi was responsible for the design of a master drainage plan as well as a water and sewer service plan. In collaboration with the project landscape architect and remediation consultant, we provided expert advice on park grading, the efficient location of water and sewer service connections, and the placement of green infrastructure elements such as bioswales, infiltration trenches, and vegetated overflow channels. Our work will result in the creation of a modern park that will provide safer waterfront access, multiple recreation amenities for the local community, as well as much-needed relief for the combined sewer system.