Listed below are examples of success stories, best practices, and/or innovative tools/approaches. This section will grow as entries are submitted or links to other sites with useful examples are provided. If you believe your agency has utilized a best practice/approach that others could learn from, please submit a short description to AASHTO (including any pertinent links) on the Share Info with AASHTO form. Please note that currently submissions are only being accepted from governmental entities.
EPA has a website that documents case studies on green infrastructure. Link to: Green infrastructure case studies web page.
EPA also has published a report presenting case studies of how 12 local governments developed and implemented policies for managing stormwater using green infrastructure. Examples of policy approaches include capital and transportation projects, stormwater regulation, demonstration and pilot projects, stormwater fee discounts, and other incentives. The report is intended to serve as a policy guide for municipalities, and includes descriptions of the most common and influential policies; background on how each policy approach works; and examples from the case studies about results, barriers, and processes for implementation. For more information, link to Green Infrastructure Case Studies: Municipal Policies for Managing Stormwater with Green Infrastructure.
The Arizona Department of Transportation has developed a manual to ensure compliance, provide consistency, and increase awareness of permitting and certification requirements for its projects under Sections 404 and 401 of the Clean Water Act. The ADOT Clean Water Act Sections 404/401 Guidance Manual, issued in October 2013, provides ADOT-specific guidance for obtaining and complying with required permits and certifications.
ADOT 404/401 Program Coordinator Julia Manfredi said the manual was developed to assist ADOT staff in project development as well as maintenance and construction. In response to a 2010 404 permit violation and a desire to improve its compliance efforts, ADOT added a 404/401 program coordinator to its staff, conducted a wide-ranging training program for hundreds of employees, and developed the Guidance Manual to provide additional guidance.
Manfredi said one of the purposes of developing the manual was to help determine when certification and permits are needed for maintenance activities, in addition to construction activities. Common "waters of the U.S." that would be subject to regulation in Arizona include washes, rivers and streams, natural ponds, wetlands, and canals.
Construction activities that could trigger Section 404/401 compliance by ADOT include culvert or bridge construction, roadway and utility crossings and geotechnical borings. Examples of maintenance activities would include channel bank protection, wash realignment and channelization and removal of sediment buildup from culverts.
Step-by-Step Process Outlined
The guidance manual provides a step-by-step permitting decision process for transportation agency staff. It outlines the following process both for construction and maintenance activities:
The manual also provides information on staff roles and responsibilities, timing of permit decisions, clarification on how Corps guidance applies to ADOT, information on the internal coordination processes for construction activities and for maintenance activities, documentation for non-notifying permits, and check lists and flow charts. A link to the manual has been distributed widely, including districts and district engineers, and has been the subject of a series of webinars, she said.
Manfredi said the manual, which took about six months to develop, is currently in use and has been well-received by ADOT staff and regulatory agencies. She said it has helped to simplify the process and empower those required to make permit decisions. The process of developing the manual went smoothly, in large part because it was developed through a collaborative effort of ADOT staff and district offices, the Corps, and the Federal Highway Administration, she said.
She also noted that the manual - which includes a range of check lists and templates that are also available on the ADOT website - is a work in progress and will likely be updated on an ongoing basis. Future efforts will include ongoing compliance tracking and additional audience-specific training programs.
Manfredi said the manual could be used as a starting point for other state DOTs looking to document their own CWA Section 404/401 permitting processes - particularly western states in arid climates. The step-by-step process for permit decisions could be adapted for most any state, she added. ADOT anticipates the manual will help avoid permit violations and will help ensure better protection of resources by training staff how to better identify resources in the field. It will also serve as a streamlining tool by simplifying the process and allowing better use of time and resources within the agency, Manfredi said.
More effective mitigation for unavoidable wetland losses from transportation projects in Florida is being achieved through a unique programmatic mitigation approach developed by the Florida Department of Transportation.
The state’s "Revised Mitigation Statute," in combination with Florida’s Uniform Mitigation Assessment Method and a new General Permit for FDOT issued by the U.S. Army Corps of Engineers, have provided a framework for the programmatic mitigation approach.
Given Florida's geology, FDOT construction projects often required the unavoidable loss of wetlands. In 1996, the Florida Legislature passed a law (the Mitigation Statute) to standardize and expedite situations where mitigation was required to compensate for the unavoidable loss of wetlands from FDOT’s projects. The 1996 statute required FDOT to pay the appropriate Water Management District (WMD) a fee established by the statute per acre affected by the FDOT project. With the WMDs tasked with protecting and managing their water resources, funding from the mitigation budget of an FDOT project would allow the WMDs to achieve their water resource protection and management effort, thereby mitigating the loss of wetlands from the roadway construction.
The law was forward thinking for its time. However, important portions of the law became outdated, and in 2014, the Florida Legislature passed revised language designed to give FDOT more flexibility to obtain full value for their wetlands mitigation expenditures (Title XXVIII, Chapter 373, Section 373.4137), commonly referred to as the "Revised Mitigation Statute."
|Florida DOT's programmatic approach for wetlands benefits species such as the wood stork. Photo: FDOT|
The "Revised Mitigation Statute,” passed in 2014, has a number of innovative elements.
Wetland Functions Considered
The Florida Department of Environmental Protection’s (FDEP) continued development of Florida's Uniform Mitigation Assessment Method (UMAM) and its inclusion by FDOT in the Revised Mitigation Statute helped further accountability and accuracy. This process provides a scientific basis for adjusting the gross acreage of wetlands impacted by the specific functions provided by the affected wetlands. UMAM was adopted by all state agencies and the Corps.
With the UMAM analysis substantiating the existing functions of the wetlands affected by roadway construction, FDOT is able to coordinate with the Corps and FDEP on appropriate mitigation quantity, and thereby paying for only what is needed to mitigate the loss of wetland function.
Collaborative Effort Provides Ongoing Dividends
The "Revised Mitigation Statute" resulted from a fortunate confluence of knowledgeable stakeholders and a state legislature focused on efficiency, expedited project delivery, and an approach to mitigation that best serves the people of Florida. The effort was led by Marjorie Kirby and Xavier Pagan in FDOT State Environmental Management Office and Kathleen Toolan of the FDOT Office of the General Counsel with FDOT leadership support.
The rewrite of the Mitigation Statute involved intense negotiations involving FDOT, representatives of the mitigation banking community and FDEP and WMDs. With stakeholder unity, the revised statute sailed through the legislature because it respected the interests of all stakeholders.
The trust that was developed among stakeholders through the passage of the Revised Mitigation Statute has continued to benefit Florida as the various stakeholders continue to work directly to improve approaches to roadway project development and permitting. For example, seeing the opportunity to improve the efficiency of the permit process, stakeholders collaborated to develop a Regional General Permit from the Corps of Engineers for FDOT projects. The General Permit was issued April 8, 2015, and was designed to include the Revised Mitigation Statute. It also incorporates such features as:
FDOT continues to push ahead with proactive, programmatic approaches to wetlands as well as biological impacts. For example:
Florida is now benefiting on several fronts from the collaborative approaches that have been and are being developed to address the unavoidable wetlands and biological impacts of road construction, according to the state DOT officials. This is the result of a successful public-private partnership that has helped build trust and communication pathways to clarify, simplify and focus, laws, coordination and procedures to develop better outcomes for the environment and the users of the transportation system.
For more information on FDOT’s wetland mitigation approach, contact Marjorie Kirby, FDOT Environmental Programs Administrator at Marjorie.Kirby@dot.state.fl.us, or Xavier Pagán, FDOT Natural & Community Resources Administrator, at Pagan, Xavier.Pagan@dot.state.fl.us, State Environmental Management Office, Tallahassee, Fla.
An online tool developed by transportation and environmental agencies is helping transportation officials in Maryland identify watershed restoration and mitigation opportunities for projects.
The Watershed Resources Registry was developed by the Environmental Protection Agency, the Federal Highway Administration, the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, the Maryland State Highway Administration, and others. Launched in the spring of 2012, the web-based tool is being used to identify opportunities for watershed restoration or mitigation in connection with federally funded projects requiring compliance with federal environmental and transportation laws.
According to a fact sheet, the geographic information system (GIS)-based tool was developed to analyze watersheds and identify the best opportunities for the protection of high quality resources, restoration of impaired resources, resource conservation and planning, and improvement of stormwater management.
Maryland SHA is using the tool to assist in avoidance and minimization of impacts during planning, design and maintenance operations, according to Sandy Hertz, Deputy Director of SHA's Office of Environmental Design. Additionally, the tool is used to prioritize watershed needs when a construction project requires mitigation. SHA staff gathers environmental inventory information and identifies potential mitigation sites using the registry.
|The Watershed Resources Registry helps MDSHA locate high-quality wetland mitigation sites, such as Lizard Hill, in Maryland. Photo: MDSHA|
The tool also helps with initial field reconnaissance by providing data that can be exported to a print map, including GPS coordinates for navigation. The tool helps to streamline information collection and preparation for permit processes, aids in National Environmental Policy Act and state environmental reviews, and is used to justify mitigation site selection as part of the review process. In addition, the tool allows SHA to achieve multiple goals using limited resources.
Recently, SHA used the registry in the preparation of the MD 4 Project Planning Study Preferred Alternative Concurrence Package, according to Hertz. Based on acreage replacement ratios agreed upon by the Corps of Engineers and the Maryland Department of the Environment, the proposed project would require just under one acre of compensatory mitigation for wetlands. A review using the tool was completed to identify potential wetland mitigation sites in the Patuxent River and Lower Potomac River watersheds. The registry identified significant acreage with potential for wetland restoration within both watersheds, Hertz said.
The tool, which can be publicly accessed over the web using typical web browser software, includes an abundance of data for identifying restoration or preservation opportunities, including maps, GIS layers, GPS coordinates, federal hydrological unit codes, and an analysis of the ecological needs of each parcel.
|Source: Watershed Resources Registry|
Users typically would begin with the "find opportunities" template. The template guides in the selection of opportunities for restoration or preservation in compliance with one or more federal resource statutes and includes four ecosystem types:
The WRR Technical Advisory Committee has created a ranking system applicable to each opportunity by performing suitability analyses. Each watershed or waterway segment has a score of 1 to 5 based on these analyses and is mapped using GIS data.
Once opportunities have been identified, various GIS layers can be switched on or off, including satellite imagery, and the locations can be viewed at multiple scales, showing their spatial relationships to nearby features.
When a site is selected, the tool provides location details that include the reasons the parcel is suitable for a mitigation or restoration opportunity and its particular ranking. For instance, a site with a score of four for stormwater compromised infrastructure restoration means that a significant number of criteria that reflect the disruption of the natural hydrologic system by stormwater are present at that location. The criteria were developed through the suitability analysis process.
A user can access the tool to identify sites that are consistent with environmental regulatory requirements and have the best potential for mitigation or restoration based on available data, according to Dominique Lueckenhoff, Deputy Director of EPA Region III Water Protection Division.
The tool includes a training video for new users, technical documentation about the suitability analyses, and a user guide. In addition, there is access to all the underlying data that allows for more sophisticated GIS analysis, according to Ellen Bryson of the Corps of Engineers, Baltimore District.
The tool currently contains data only for the state of Maryland, but its internal architecture is flexible enough to eventually serve other states and jurisdictions, according to officials who have worked on the registry from the beginning.
Developing the Registry
The registry began as an idea for using a watershed-based approach for planning a transportation project in Maryland, Lueckenhoff said in an interview. In 2006, discussion had begun on plans for improvements to U.S. Highway 301 in Charles and Prince George's counties, in Maryland, that would use the "green highways" principles, taking a watershed approach to sustainable infrastructure planning and delivery. As the various agencies came together on the project, there was talk about a "watershed bank" that would "become a multiple end-user product" and achieve benefits beyond just the one project to address U.S. 301, according to Lueckenhoff. "It could serve future projects and help preserve and restore resources, in addition to being supported through various credit markets," Lueckenhoff said.
It was clear that the U.S. 301 project was trying something new. The Maryland SHA along with federal and local agencies were attempting to build a highway in such a way that both the transportation needs and the environmental needs were met within a highly sensitive area encompassing four watersheds, according to SHA's Hertz.
Starting with a geographic information system (GIS) and data on watershed resources developed during the U.S. 301 planning, the WRR partners also added the regulatory requirements of the various statutes that affect watershed health, said Denise Rigney, an environmental scientist with EPA Region 3. The desire to bring the needs of watersheds earlier in the NEPA process and other planning processes led to the registry concept, Lueckenhoff said.
There was a "groundswell of partnership in Maryland," said Lueckenhoff, allowing for the product to eventually expand statewide. There was support from the top for this, Lueckenhoff said, but more importantly, it was built from the bottom up, addressing the needs of those at the field level.
The usefulness of the Watershed Resources Registry has exceeded expectations, Lueckenhoff said. All of the team partners – EPA, the Corps of Engineers, Maryland SHA, and FHWA – are using the tool.
Other agencies are using the tool as well. Field inspectors are using it to preview sites before a visit, local agencies are using it, and there is growing interest from the public. "There are uses that we didn't even imagine it for," Lueckenhoff said.
One of the most satisfying things is that the registry is the result of successful interagency collaboration, officials said.
It "evolved out of the willingness" of the various agencies to step outside their comfort zones, Lueckenhoff said.
This cooperative environment has been exciting, Bryson, of the Corps of Engineers, agreed. By bringing together the various types of information into one integrated tool, people are creating new kinds of information that weren't possible before, said Bryson. Members of various agencies can coordinate over the web and be assured that they're all looking at the same thing. "All the agencies are together on this," Bryson said.
The agencies continue the development process by meeting once a month to discuss improvements. As data change, they will be added to the tool, Bryson said. As new models are developed, the tool will be tweaked to accommodate them.
Also going forward, sites that are identified by the tool will be inventoried with site visits, and information regarding selected or completed restoration projects will be added, said Ralph Spagnolo, a wetland hydrologist with EPA Region III and a member of the WRR Technical Advisory Committee.
The Baltimore District of the Corps of Engineers includes portions of Pennsylvania, and Bryson said that a roll-out of the registry using Pennsylvania data is likely.
In producing a registry for another state, developers would be able to take advantage of the eight pre-existing suitability models in the Maryland WRR and start with available federal and state data, according to Lueckenhoff. An interagency technical advisory team or committee should be established (or utilized if one already exists) to collaboratively identify stakeholder needs and interests and evaluate to what degree the data and existing models are able to address them.
Due to the work done already, the next state will be able to develop and use its registry in significantly less time than it took for the initial development in Maryland, according to Lueckenhoff. The team already has been approached by several Mid-Atlantic States for transfer of the WRR to address a variety of needs, Lueckenhoff said. "It is highly adaptable, without being overly complex and challenging to multiple end users. This is a pretty good [model]," she said.
The registry has been selected to receive technical assistance from AASHTO's Technology Implementation Group, chosen as a National Water Program Best Practice by the EPA, and included in a handbook issued by the Environmental Law Institute.
The Watershed Resources Registry is available at http://www.watershedresourcesregistry.org/. For more information, contact Dominique Lueckenhoff (firstname.lastname@example.org) or Ralph Spagnolo (email@example.com) at EPA, or Sandy Hertz at Maryland SHA (firstname.lastname@example.org).
The New Hampshire Department of Transportation’s award-winning work managing construction stormwater to protect two water bodies adjacent to Interstate 93 has been a successful demonstration of innovative techniques under real-world conditions.
NHDOT took a completely new approach, especially for the temporary stormwater controls, when widening and reconstructing I-93 south of Manchester where it passes between Canobie Lake and Cobbett's Pond, according to NHDOT’s Director of Project Development Peter Stamnas.
The proposed work on the segment, a nearly three-mile stretch at Exit 3, prompted significant public concern over the potential for turbidity and sediment affecting the nearby water bodies, especially Canobie Lake which provides local drinking water.
I-93 between Manchester and the Massachusetts border had not been significantly upgraded since it was built in the early 1960s, according to project documentation. NHDOT was faced with performing major construction while still meeting the New Hampshire Department of Environmental Services’ stringent water quality standards and the public’s demand for the cleaner construction.
Knowing that the entire 20-mile project, and the Exit 3 construction in particular, was constrained by the natural geography, NHDOT “really had to start from scratch from a design standpoint” to create a solution for the construction stormwater that would meet NHDES standards and receive public support, according to Stamnas, who joined the project in 2006.
NHDOT used a “new design approach that would be similar to a traffic control plan” but applied to construction stormwater, Stamnas said. The agency reviewed the entire length of the project, analyzing the runoff risk and calculating runoff volumes. Prior to the construction phase, staff identified the areas that would require stormwater controls, resulting in a comprehensive stormwater management plan.
The agency faced constraints within the right of way regarding the surface area for stormwater storage, the hilly terrain, and the nearby water bodies, and had to devise innovative solutions. “There was just too much water and not enough real estate,” Stamnas said.
NHDOT maximized the limited land available within the right of way by collecting water wherever possible and using a system of pumps and pipes to get the water “where it needed to go” for storage and treatment, Stamnas said. This had the added benefit of reducing the number of treatment cells that needed to be constructed.
|New Hampshire DOT uses innovative methods to pump and divert construction stormwater for treatment on I-93 project. (Photo: NHDOT)|
Treatment with Polyacrylamides
Canobie Lake and Cobbett's Pond created significant challenges since they are the low geographic points along Exit 3 and “everything went there,” Stamnas said. NHDES standards for class B waterbodies (Cobbett’s Pond) require down stream flows not be increased by more than 10 nephelometric turbidity units (NTUs) after the introduction of the stormwater flows. For Class A waterbodies (Canobie Lake) the standard is further reduced to a 0 NTU increase above background levels.
To address this, the agency pioneered a program for linear highway projects which included flocculent system designs, contract bid items, and procedures for the construction use of anionic polyacrylamides (PAMs) as a flocculant to induce the suspended solids in the runoff to form larger flakes. These particles then could be filtered out or allowed to settle, turning sediment-clouded runoff into clear water that would not disrupt local water quality.
NHDOT started out using self-dosing blocks that control the release of PAM into the runoff water. The flocculant was added to a flocculant dosing tank system. The water was then run through in-ground settling basins and clarifying structures that used filtration baffles.
In 2008 and 2009, “we were on the cutting edge” of PAM use from a linear construction standpoint, Stamnas said, and the dosing and filtration methods evolved over time during the project. At the beginning, NHDOT had “difficulties” receiving regulatory approval to use PAMs but “we finally worked through it,” Stamnas said.
The regulators’ concern was that NHDOT would use too much PAM, causing it to be a pollutant itself. Stamnas said eventually they were able to prove that they could make effective use of the flocculants without creating a hazard to water quality. The agency found that by switching from self-dosing blocks to PAM powders, the dosage could be controlled more accurately.
Techniques also were used to divert water that was coming into the site, directing it through bypass pipes so that it did not pick up sediment. This lowered the amount of water that required treatment, Stamnas said.
In addition to treatment, PAMs were used as a soil stabilizer for disturbed slopes.
Contracting and Costs
The significant permanent stormwater retention structures and the locations for construction stormwater controls were included up front in the original contract documents, Stamnas said.
NHDOT provided base plans, required contractors to provide more detailed stormwater control plans, and set up regular meetings to review progress. This allowed the contractors and the field staff to be a lot more prepared, Stamnas said. Conventional erosion and sediment control best management practices (BMPs) and typical management approaches to construction were determined to be inadequate and unnecessarily expensive, Stamnas said.
Also, agency planners and designers created strategies and tools they knew would work in various situations and that could be applied to address field conditions. It provided the contractors and the field staff with options from which they could make decisions based on the situations they were presented with, Stamnas said. Examples of these tools included hydraulically applied mulch systems, unit water diversion items, standard pump and pipe systems, and a packaged flocculent treatment system. NHDOT provided the proposed collection of tools early on so that contractors could bid on them up front rather than including them later through change orders or creating a situation where there was a sole-source supplier.
The construction work at Exit 3 cost approximately $150 million. The agency wanted to place the stormwater controls into the bidding environment to achieve some level of economy. NHDOT was looking for ways to reduce costs, Stamnas said, “and I think we did that.”
According to NHDOT, completing a construction stormwater assessment during the design phase of large projects pays dividends. It identifies potential risks early and allows items to be included in the contract to minimize costs and mitigate risk potential. Also, contractors are more prepared, and it reduces their time to prepare stormwater protection plans, so work can start sooner.
Diverting water around the active construction zone is critical and constructing temporary sedimentation basins as early as possible reduces treatment efforts.
Also, the construction site is constantly changing, and strategies that work one month may not work as well the following month. The matrix of tools allows for solutions to be implemented quickly and cost-effectively.
Additionally, PAMs are very effective in reducing turbidity in construction runoff and are safe for the environment when used properly. They reduce soil loss, reduce phosphorous levels in treated stormwater, have negligible effect on water pH, and lower biochemical oxygen demand in runoff.
Traffic was placed in the final lane configurations through the Exit 3 area over the summer and this segment of the corridor project was declared substantially complete in November of 2016. Four more years of construction lie ahead along the remaining segments of the 20-mile corridor project.
The Exit 3 stormwater control project earned NHDOT the “Best Use of Innovation” award in the medium-sized project category from the Northeast Association of State Transportation Officials (NASTO) for its efforts to protect the natural resources.
“It’s a new way of looking at linear construction and it’s working really well,” Stamnas said. Based on the size and complexity of future projects NHDOT now has a comprehensive list of strategies to draw from for use around the state.
A facility to help practitioners test the effectiveness of stormwater treatment technologies is being developed by the Oregon Department of Transportation.
The Stormwater Technology Testing Center (STTC), under construction at the Northeast Portland Maintenance Yard, is intended to provide designers and users of stormwater treatment technologies a tool to provide non-biased assessments of the effectiveness and maintainability of technologies being considered for installation at their facilities, according to Paul Wirfs, P.E., Deputy Geo-Environmental Manager.
Officials hope the new center – which is expected to open in 2017 – will help develop information on the maintainability and life cycle cost for stormwater treatment technologies that will help to protect the environment and transportation investments.
Background on Testing Center Development
State and federal agencies, together with environmental organizations, have expressed increasing concern regarding the effectiveness of stormwater treatment devices and facilities in achieving water quality standards required by permits. Transportation agencies also face ongoing concerns over maintenance costs related to stormwater treatment.
The concept for the STTC was developed by a group of stormwater professionals that ODOT convened in 2011 to discuss the challenges and ways to improve the management of large stormwater programs. The group included representatives from ODOT, other state and local agencies, and the Washington Department of Ecology (WDOE). A board has been established to provide direction on the operation of the STTC including local, state, and federal agency representatives from Oregon, Washington, and California.
Although WDOE and several other agencies had facilities or protocols established to evaluate pollution removal effectiveness of stormwater treatment devices, they could not demonstrate the capability of a long-term stormwater treatment device, the maintenance required for the technology, the costs of maintenance, and at what point the technology would fail and require replacement.
Over a two-year period between 2009 and 2011, the STTC concept was developed, including a business plan, maintainability evaluation protocols and a quality assurance project plan.
The STTC Board identified several potential sites for the center, ultimately choosing the Northeast Portland Maintenance Yard site. The site provided adequate stormwater supply and representative stormwater, an adequate facility site area with the possibility of expansion, an appropriate discharge point, and gravity flow stormwater conveyance to the testing facility. In addition, the site offered safe access and was already owned by ODOT.
Officials also noted that the STTC was one of several projects that ODOT funded to meet the commitments of a settlement agreement in response to a notice of intent to sue over alleged permit violations.
The Northwest Environmental Defense Center alleged that ODOT was not in compliance with its National Pollutant Discharge Elimination System Municipal Separate Storm Sewer Systems (MS4) permit. While that allegation was never proven, ODOT officials said the agency “chose to invest in stormwater improvement rather than on litigation.” The STTC qualified as part of that investment along with multiple other stormwater retrofit projects within the Willamette River Watershed.
The Art and Science of Stormwater Testing.
The testing center consists of a combination of pumps, pipes, an air compressor, sensors and computers that work together to gather representative stormwater samples for laboratory analysis.
The STTC includes 3 “pads” or “test bays” where each technology is connected to the testing center control and piping systems. The technologies can be installed at the appropriate elevation and configuration as defined by the specifications provided by the owner of the technology. This is all located within the footprint of the STTC.
Stormwater is diverted from a 7-foot diameter drainage pipe along Iâ€ 205 at Columbia Slough to a large manhole called the feed wet well. A pump recirculates the stormwater and the debris in the feed wet well, allowing suction pipes to pull in a representative sample of the pollutants in the stormwater.
High-velocity vacuum samplers pull samples of the raw stormwater into jars to be sent to a laboratory for analysis. The diameter of the suction pipes, which varies from 2 inches to 4 inches depending on the pumping flow rate, ensures that flow velocity is fast enough to move sand and other debris along and carry it to the test bays. Clear PVC pipe and clear hose allow pipe-flow to be monitored, especially when leaves and sand are entering storm drains.
The process also uses a “programmable logic controller” that controls pneumatic valves in order to match the suction pipe diameter to the required pump speed. It monitors the water surface in the feed wet well and test bays with sensors to determine if too much water is being sent to the technology being tested. If the water level is rising and is about to bypass some of the raw stormwater, the programmable controller slows the dosing flow rate. All of the data regarding the water surface and flow rate are sent to a remotely operated computer program for archiving and analysis.
Ultimately, samples are sent to the laboratory, where the influent and effluent are analyzed for pollutant levels, providing data on the removal efficiency of the technology being tested.
The site is currently configured to test any type of vault, filter, or manhole shaped devices, and it can test up to three technologies simultaneously. The site also can be expanded in the future to test swales, slopes and small ponds.
“Currently, we can run the system and have made a few test runs,” according to Dan Gunther, a hydraulics engineer at ODOT. “We are still working on the software and controlling the site remotely,” he said. Testing of technologies will begin in earnest once all the software and remote controls are installed.
Quantifying Technology Costs, Maintainability.
ODOT officials said the STTC will help to quantify the maintainability performance characteristics and costs of commercially ready stormwater treatment technologies. It is available to serve as a national laboratory for the professional stormwater community and will provide an unbiased and credible assessment of stormwater treatment technologies.
ODOT intends for the STTC to become a self-sufficient facility, supported by testing fees; however, financial support by owners and operators of stormwater technologies will ensure continued operation of the facility. In the future, the facility may be expanded to include additional testing bays and testing parameters such as dosing, bacteria, nitrates and more.
In terms of challenges, officials said it has taken longer than planned to obtain start-up funding and to get the facility up and running.
In that regard, states can help support the center by contributing to an ongoing Federal Highway Administration pooled fund program. A total of $300,000 is being requested to go toward business management services, calibration and testing, and data protocols. So far, a total of $125,000 has been committed, including $100,000 from Pennsylvania DOT, $15,000 from Washington State DOT, and $10,000 from the Port of Portland.
Other elements of the STTC calibration and start-up have been funded by a State Transportation Innovation Council grant from the Federal Highway Administration.
To date, ODOT has invested approximately $950,000 on the concept development and construction of the center. One more push of funding will move the project forward to full operation when testing can begin.
In addition, ODOT officials said they would like to hear from other DOTs that are interested in joining the Board or participating as a stakeholder.
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