Regulatory Issues: What’s Ahead for the Industry?
Another potential source of work for the erosion control and stormwater industries is Section 438 of the Energy Independence and Security Act (EISA). With the goal of protecting and restoring wetlands, the law requires federal facilities to meet predevelopment hydrology for new building construction of more than 5,000 square feet by using nonstructural and structural best management practices (BMPs) to the maximum extent technically feasible.
The Low Impact Development Center and Tetra Tech, under contract to the USEPA, are developing a guidance document to provide the framework for the high-performance approach, requiring innovation and research to develop a system that is both highly effective and economically efficient.
Section 438’s emphasis on predevelopment hydrology will promote the natural flow of water by using vegetation to intercept rainfall and evapotranspirate moisture back to the atmosphere. Other green infrastructure practices will include natural infiltration through undisturbed or enhanced soils and water harvesting systems that collect and reuse rainfall onsite.
Just how erosion control specialists execute their jobs may soon change, however. The EPA expects to have a final rule by December with respect to its proposed effluent limitations guidelines (ELGs) and new source performance standards (NSPS) to control the discharge of pollutants from construction sites.
Through “Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category,” the EPA intends to tighten controls on discharges from construction sites by establishing national technology-based effluent limits and performance standards in concert with existing state and local programs. Once implemented, these new requirements are expected to significantly reduce the amount of sediment and other pollutants discharged from construction sites. All construction sites would be required to implement a range of erosion and sediment control BMPs to reduce pollutants in stormwater discharges. Construction sites disturbing 10 or more acres at a time would also be required to install sediment basins to treat stormwater discharges.
For sites 30 acres or larger located in areas of the country with high rainfall intensity-either an R factor of 50 or greater from the Revised Universal Soil Loss Equation (RUSLE2), or a high total annual rainfall for areas in which the R factor has not been calculated-and soils with a clay content of more than 10%, stormwater discharges would be required to meet a numeric limit of 13 nephelometric turbidity units (NTUs) or less. NTUs are a measure of sediment in the water related to fine-grained and slowly settling or non-settleable particles.
Exempt from the limit would be discharge from rainfall exceeding the local two-year, 24-hour storm.
Meeting the proposed numeric turbidity limit could require using active treatment systems (ATS), such as adding chitosan or other polymers to promote flocculation, followed by filtration of stormwater discharges. Electrocoagulation also is a possible technological approach capable of reducing turbidity levels.
The EPA had judged the potential for the overuse of polymers creating toxic discharge as being low, as polymers are widely used in wastewater treatment facilities.
Sediment is one of the leading causes of water-quality impairment nationwide, and the deposition of sediment from construction has contributed to reducing water depth in small streams, lakes, and reservoirs, leading to the need for dredging, according to the EPA.
The proposed rule is projected to reduce the amount of sediment discharged from construction sites by up to 27 billion pounds each year at an annual cost of $1.9 billion. It is expected to improve drinking water supplies and aquatic environments, and to require less dredging of navigation channels and reservoirs.
Reactions From the Field
Steven Parisi, CPESC, owner of Turfmasters in Moscow Mills, MO, believes the stricter requirements concerning construction and development sites will most likely require the use of flocculants, polymers, or filtering systems.
“It has been our experience with the sites that we have dealt with that it is much more costly and complicated to discharge almost completely clear water from a job site,” he says.
“Each site has its own distinct set of challenges,” he adds. “We have successfully performed this process on some job sites without the holder of the land disturbance permit incurring any fines or stop work orders, but it seems almost impossible to stop all suspended clay particles from leaving construction and development sites.”
Parisi says projects his company has worked on typically require that a good portion of the land being developed must be used for detention and settling-type basins. “This is always a detriment to a builder or developer who wishes to optimize the land for buildings and parking instead of using the land to clear the water up before leaving the site,” he says. “What the developers must understand is that despite the costs, this is the way things are heading. It will more than likely drive up the cost of all future development just like NPDES [National Pollutant Discharge Elimination System] Phase I and Phase II have. I do not see a way around significantly increased costs.”
To set such limits “generically across the country is a mistake,” says Jo Moore, an environmental safety and health director for a south Florida construction company.
“In many places, existing waters already have natural or existing impacts that exceed those limits, especially after a rain event,” Moore says. “Waters in residential areas are negatively impacted by various discharges, including residential properties where people are not actively maintaining vegetative cover, such as large bare areas in their yards.”
In her travels through hilly parts of North Carolina, Moore has witnessed red water coming down many dirt driveways.
“Those discharges eventually combine with other waters,” she notes. “There have been times when waters we discharged into were already exceeding 50 NTU-daily background-and it is costly to require contractors to improve on existing [conditions].”
Moore says that although she recognizes requiring contractors to treat waters discharged from a site is easier than identifying all other dischargers in a watershed and regulating them, “it should be understood that increasing the cost of construction will only increase the cost to residential and commercial owners.”
Moore cites Florida as an example of government that has an effective structure in place, with five water management districts to regulate waters in their respective areas. Her company works in two of the districts, each having different discharge limits.
“For projects discharging to protected waters, called Outstanding Florida Waters (OFW), the limit is 0 NTU over background,” says Moore. “Normal background in these waters can range from 0 to about 5 depending on the time of year, recent rain events, and so on. Wetlands and tributaries to these waters require the same protection.”
Moore points out that in Florida, attached wetlands can be as far as 5 miles away, because there is so much surface water in Florida.
“The discharge limit to other waters, such as a collector canal, is 29 NTU over background,” Moore says. “I have seen background waters ranging from 5 to 15 NTU. The higher values were found after a rain event. Establishing a national standard of 13 NTU would require treatment results better than background.”
Jerry Fifield, a professional hydrologist and president of HydroDynamics Inc. in Parker, CO, says he’s glad to see the EPA is addressing such erosion and sediment control concerns on construction sites.
“The EPA is embarking upon a new territory that has been needed for many years-namely, identifying ELG limitations,” he says. “However, what the EPA has presented raises many more questions about methods and techniques than it solves problems.”
What the EPA proposes is achievable “only if you have enough money, and that’s the bottom line,” he says. “It’s not practical. And not being practical means that it could be very expensive and be very detrimental to the construction industry if modifications do not occur.”
Fifield’s two major concerns are discharge of water so clean that it could harm downstream ecosystems, and sizing criteria for ponds that would make them so large that “there is not any construction area that is going to have that capacity to treat the water as recommended by the Environmental Protection Agency.”
In a letter to the EPA, Fifield told the agency it is relying too heavily upon the R factor to calculate annual erosion rates based on 10-year, 24-hour storm events.
“While [the RUSLE2 equation] has an algorithm to calculate sediment yield, it should not be used to determine possible sediment loading for a single storm event,” Fifield points out.
He says the EPA’s reliance on effluent limitations for sites meeting all three criteria-average soil clay content of more than 10%, an R factor of 50 or more, and an area of 30 acres or more-does not meet “real world” sediment loading from disturbed lands.
“Soil information from maps only reflects historic conditions and does not represent what happens while construction activities occur,” he says. “Also, such maps do not address what happens when import material with high clay content is introduced into a project.
“There is nothing magic about an annual R factor of 50 or more. If a significant rainfall event occurs in an area with R factor of 34, then significant erosion will still occur.”
Fifield says erosion rates are independent of area but are dependent upon rainfall intensity, soil erodability, slope, flow path length, and sediment and erosion control BMPs.
He adds that the EPA should apply ELGs to all sites where construction activities occur, regardless of soil’s clay content, R factor, or size. “To do so otherwise will not protect the environment and could possibly result in filing of future lawsuits against the EPA,” he says.
Fifield says there are three methods by which sediment runoff can be reduced: retention, detention, and flow-through systems.
Retention captures all runoff for a specified frequency storm. “A retention system is the most effective method of removing sediment from runoff, because controlled discharges do not occur,” says Fifield. “However, since contained waters do not leave the system, there is a potential for damage to the structure if succeeding storms cause runoff to enter the containment structure before total removal of contained water has occurred.”
Detention-which Fifield says the EPA “mistakenly” identifies as retention-contains runoff and allows for low discharge rates once it has been demonstrated that sedimentation of untreated sediments larger than 0.02 millimeters can occur. The EPA is recommending detention times of at least 72 hours.
“EPA’s continued emphasis on using a detention system is adequate for water-quality treatment system for post-construction conditions,” says Fifield. “However, for large inflows of sediments that can occur during construction activities, the detention system may not be adequate.
“Also, if runoff waters are discharging, such as over 72 hours, it is not necessary to have a length-width ratio of 4:1 to capture 0.02-millimeter-diameter and large particles,” he adds. “However, when runoff waters are discharging from a containment system at a high design discharge rate, such as over a spillway, then the length-width ratio must be at least 4:1, with preference for a higher value.”
The EPA recommends calculating containment volume of runoff from a two-year, 24-hour storm, or 3,600 cubic feet per disturbed acre, says Fifield.
“All designers must know how to calculate runoff for a two-year, 24-hour storm event,” Fifield points out. “Thus, I recommend eliminating the option of using 3,600 cubic feet per disturbed acre, since it does not accurately reflect the amount of runoff for a two-year, 24-hour storm event where large rainfall events occur.”
A flow-through system is used with no 72-hour detention requirements once it has been demonstrated that sedimentation of large-diameter, design-size particles or polymer-treated sediments can occur to allow for high inflow and outflow values, says Fifield.
“The flow-through system must be available for trapping sediments where the design-size suspended particle is much greater than 0.02 millimeters,” he says. “In this manner, high inflow and outflow values can happen. This can occur for any design-size particle by treating incoming sediments with a polymer-preferably anionic-to create a large mass of suspended particles that fall through the water column at an accelerated or high terminal velocity rate.”
Fifield says once this occurs, there is no need for large surface areas (about 2% to 6% of the size needed for a detention system) and for short flow path lengths (about 13% to 25% of the length needed for a detention system).
“More importantly, there is no need to contain, pump, and treat runoff waters, as with an active treatment system,” says Fifield. “The EPA needs to assess all types of containment structures and not be advocating only large detention systems. What the EPA has presented does not represent how suspended particles can be removed in a practical and cost-effective manner.”
Fifield says while it is “noble” to have nationwide limitations of 13 NTUs on discharges from an active treatment system, “it simply is not practical to achieve such lofty standards.”
The reason, says Fifield, is that it produces water that approaches the standard of drinking water, “which does not simulate historic sediment loading conditions. Such clean waters will be detrimental to downstream ecosystems.
“For example, wetlands obtain their nutrients from sediment-laden waters,” he says. “Removal of the historic sediments may result in damage to downstream wetlands. Such clean waters will accelerate the ability of streams to erode their embankments and channel bottoms.”
It has been proposed that passive systems such as flow-through systems should have limitations of 50 to 150 NTUs. But, Fifield notes, “Even these might be detrimental. We suggest that the EPA explore how to achieve a performance standard by requiring an ELG that is equal to or a percentage above-such as 20%-historic background conditions.”
He says it is possible to develop performance standards to ensure that historic sediment loading rates continue. Additionally, this approach makes use of “loading factors” that simulate sediment discharges using local soil conditions and hydrologic conditions.
“Converting from a sediment load method to a turbidity measurement system should not pose any large problems,” he adds.
Fifield says the use of polymers would still require a large area to contain runoff. “It ignores the ability of all polymers to be able to allow the deposition of suspended particles by a proper design,” he says. “We’ve come up with a way to reduce the size of a pond from the EPA’s version to get it down to one-sixth the surface area the EPA is recommending.
“But you’re going to be precluded from using that technique if, indeed, we are required to follow what the EPA says has to be done-to capture the runoff for a two-year, 24-hour storm event and hold it for 72 hours before it all drains out. It’s effective, but it’s an archaic method of how to take care of suspended sediments in runoff waters.
“I recommend the EPA totally throw out anything relating to the R factor and to whether or not you’ve got clay content of 10% or more. Just apply the criteria to all construction sites, but do it in a manner that’s practical and cost effective.
“Let us come up with systems that do work on a construction site rather than have such huge holding areas that nobody can afford. And design to a size particle for local conditions. Everyplace you travel, the soils are different. The sand in Florida is a lot different from the soil of Georgia, which has a lot of clay in it. So the size of a pond capturing a sandlike particle should be a lot smaller than the size of a pond to capture claylike particles. And anytime you go through a construction site, you have the existing material, but you often bring in brand new material from the outside, which may have a lot of clay in it that nobody knows anything about.”
National Research Council Report
In a related consideration of regulations, the EPA is examining recommendations put forth by the National Research Council in a report calling for an overhaul of the EPA’s stormwater program.
One of the NRC recommendations is that stormwater and other wastewater discharge permits be based on watershed boundaries rather than political boundaries.
Another recommendation is that the EPA should drop the current system of separate permits for wastewater and stormwater regulations-within which different types of permits exist for municipalities, industries, and construction sites-and adopt a watershed-based permitting system encompassing all stormwater and wastewater discharges that could affect waterways in a particular drainage basin.
“We are evaluating all of the recommendations and findings within the report,” says Greg Schaner, an attorney advisor for the Water Permits Division in the municipal branch of the EPA. “There’s a cross-office team that’s been formed to look at that, so internally we’re exploring how the different recommendations could be implemented. There are a lot of decisions attached to what EPA winds up doing. At this point, we’re still evaluating and deciding what are the next steps.”
New Funding for Green Infrastructure
As for the work emanating from the American Recovery and Reinvestment Act as it relates to the Clean Water State Revolving Fund and Drinking Water State Revolving Fund, $6 billion is allocated for assistance to help communities with water-quality and wastewater infrastructure needs. Some of the funding is targeted toward green infrastructure and environmentally innovative projects.
“We’d really like to see folks take advantage of that-green infrastructure for managing wet weather with things like bioretention and green roofs,” says Jennifer Malloy, an environmental scientist with the EPA who wears a number of hats, including leader of the EPA’s green infrastructure initiative.
Malloy points out that one category within the funding is dedicated to innovative environmental projects. “That leaves the door open for people to become somewhat creative,” she says.
Malloy says states are required to spend 20% of their allocation on green infrastructure unless they can document that they didn’t get enough applications for that kind of funding.
Additionally, some $48.1 billion dollars has been allocated to the US Department of Transportation for various projects. By the end of the summer, states are expected to have a list of projects ready, and by one year from the point the act was passed on February 17, the projects must be at least under contract, if not under construction.
Erosion control specialists such as Richard Dunbar, the division manager for erosion control for Oakridge Landscape in North Hills, CA, are looking forward to what the American Recovery and Reinvestment Act will do for the industry. The bridge, road, and other construction projects on the radar for funding will require erosion control, he points out.
“Once that happens, it will get the economy going again,” he says.
Parisi agrees. “If the stimulus truly brings more money into the picture to work on roads, bridges, and other projects, then this will create more demand for erosion and sediment control,” he says. “This could significantly help the industry.
“However, I believe that it will be very important for the private sector to feel comfortable enough with the “˜free enterprise system’ to start spending money again to help fuel the economy, in addition to what the federal and state governments do.”
As these and other projects roll out, Dunbar welcomes increased industry regulations and would like to see enforcement increased to keep pace with regulations.
“The big thing in California on commercial projects is that we don’t see as much erosion control being enforced, but it is now starting to change with the housing market down,” he says.