What EPA's Effluent Guidelines Mean for Stormwater
In December, EPA published in the Federal Register the long-awaited final Effluent Guidelines for Discharges from the Construction and Development Industry. Many people within the homebuilding arena, as well as the stormwater and erosion control industries, have been waiting since the draft of the document was published a year earlier to see just how low EPA would set the numeric limit for runoff from construction sites. The answer: 280 nephelometric turbidity units (NTU) for sites of 10 acres or greater.
Operators of sites covered under the new guidelines must take water samples throughout the day, and the average of all the measurements must not exceed 280 NTU. An individual sample above that level is acceptable as long as the daily average is 280 or less. If a storm larger than the local 2-year, 24-hour storm occurs, the limitation doesn’t apply that day.
In the draft guidelines published in December 2008, EPA had proposed a limit of only 13 NTU. That is lower than the background turbidity level for some areas, and many people—not only developers—objected to such a low number. However, the lower limit would have applied to sites disturbing 30 or more acres—three times the size of those covered under the current rule—that also met other criteria of climate and soil type. Developers, of course, were concerned about the cost of complying with the guidelines. They still are—the National Association of Homebuilders released a statement in December 2009 saying that while the new rule places a burden on developers and raises prices for homebuyers, it offers little guidance on how to comply and won’t benefit the environment. But the new limit will be far easier to achieve than the one proposed a year earlier.
In the 2008 draft, EPA acknowledged that sites covered by the numeric limit of 13 NTU would likely need to use advanced treatment systems, such as treating runoff with chitosan or some other flocculant and employing a filtration system. With the higher limit of 280 NTU, such systems probably won’t be necessary for all sites; many will be able to comply using traditional erosion and sediment control practices. And yet, even for sites that do not need advanced treatment systems, the job of taking water samples and monitoring turbidity will be significant. It will require equipment that wasn’t needed on construction sites before. Until now, only visual inspection of construction-site discharges has been required (although some states have incorporated numeric limits into their permits, there has been no requirement from EPA to do so). It will also place new demands on construction site inspectors.
Whether developers choose to take on these monitoring tasks themselves, or whether they outsource them as many have done with traditional erosion and sediment control practices—things like installing and maintaining BMPs and in some cases writing the stormwater pollution prevention plan itself—remains to be seen. Either way, the rule is likely to create more business for those who have expertise in sampling and monitoring, and for the companies that produce monitoring equipment.
Advertisement
The rule will go into effect in phases: within 18 months of its publication, sites disturbing 20 or more acres will have to begin monitoring and complying with the 280-NTU limit. Four years after the rule’s effective date, sites disturbing 10 acres or more will need to comply. The full text of the guidelines is available here.
What do you think of the final guidelines? Are they too stringent? Too weak? What opportunities do you see for the stormwater industry, and what do you think the actual impact of the new guidelines will be on water quality?
Author's Bio: Janice Kaspersen is the editor of Stormwater magazine.
January-February 2010
What EPA's Effluent Guidelines Mean for Stormwater
In December, EPA published in the Federal Register the long-awaited final Effluent Guidelines for Discharges from the Construction and Development Industry. Many people within the homebuilding arena, as well as the stormwater and erosion control industries, have been waiting since the draft of the document was published a year earlier to see just how low EPA would set the numeric limit for runoff from construction sites. The answer: 280 nephelometric turbidity units (NTU) for sites of 10 acres or greater.
Operators of sites covered under the new guidelines must take water samples throughout the day, and the average of all the measurements must not exceed 280 NTU. An individual sample above that level is acceptable as long as the daily average is 280 or less. If a storm larger than the local 2-year, 24-hour storm occurs, the limitation doesn’t apply that day.
In the draft guidelines published in December 2008, EPA had proposed a limit of only 13 NTU. That is lower than the background turbidity level for some areas, and many people—not only developers—objected to such a low number. However, the lower limit would have applied to sites disturbing 30 or more acres—three times the size of those covered under the current rule—that also met other criteria of climate and soil type. Developers, of course, were concerned about the cost of complying with the guidelines. They still are—the National Association of Homebuilders released a statement in December 2009 saying that while the new rule places a burden on developers and raises prices for homebuyers, it offers little guidance on how to comply and won’t benefit the environment. But the new limit will be far easier to achieve than the one proposed a year earlier.
In the 2008 draft, EPA acknowledged that sites covered by the numeric limit of 13 NTU would likely need to use advanced treatment systems, such as treating runoff with chitosan or some other flocculant and employing a filtration system. With the higher limit of 280 NTU, such systems probably won’t be necessary for all sites; many will be able to comply using traditional erosion and sediment control practices. And yet, even for sites that do not need advanced treatment systems, the job of taking water samples and monitoring turbidity will be significant. It will require equipment that wasn’t needed on construction sites before. Until now, only visual inspection of construction-site discharges has been required (although some states have incorporated numeric limits into their permits, there has been no requirement from EPA to do so). It will also place new demands on construction site inspectors.
Whether developers choose to take on these monitoring tasks themselves, or whether they outsource them as many have done with traditional erosion and sediment control practices—things like installing and maintaining BMPs and in some cases writing the stormwater pollution prevention plan itself—remains to be seen. Either way, the rule is likely to create more business for those who have expertise in sampling and monitoring, and for the companies that produce monitoring equipment.
The rule will go into effect in phases: within 18 months of its publication, sites disturbing 20 or more acres will have to begin monitoring and complying with the 280-NTU limit. Four years after the rule’s effective date, sites disturbing 10 acres or more will need to comply. The full text of the guidelines is available here.
What do you think of the final guidelines? Are they too stringent? Too weak? What opportunities do you see for the stormwater industry, and what do you think the actual impact of the new guidelines will be on water quality?