These requirements are being levied for the construction site as well as measures for permanent stormwater management, which are designed to control and treat runoff for the life of the project.
Much of this new regulation builders are facing involves reducing contaminant loading in stormwater runoff in additionto limiting the amount of impervious surface on properties. In order to accomplish this, the use of Low Impact Development is being strongly promoted. While LID has a strong focus toward utilizing sustainable designs to promote natural hydrologic functions and enhanced site infiltration, it is also being used quite effectively by many progressive-thinking builders in arid and drought-prone regions of the U.S. as a method for retaining stormwater for reuse. These builders are increasingly viewing stormwater not as something that needs to be disposed of but as more of a resource—something that should be harvested and stored for later use because there is simply less and less of it.
Stormwater Management during Construction
For managing stormwater runoff during the course of construction, there can be multiple layers of regulation for builders to contend with. In addition to federal, state and municipal regulations, there can also be requirements from local government entities such as counties and water conservation districts. These different levels of jurisdictions may have their own set of stormwater regulations, and, depending on the project location, these jurisdictions can overlap, requiring builders to comply with more than one set of stormwater requirements.
A project could also be located in a watershed with special circumstances, such as waters within the U.S. that have a Total Maximum Daily Load. These are waters, as mandated by the Clean Water Act, that have been determined to be impaired or too polluted to meet the water quality standards set by a state or jurisdiction. “If there is a Total Maximum Daily Load requirement for the local water body that the construction site drains to, then the builder may have additional regulations to contend with,” says Glynn Rountree of the National Association of Home Builders’ Water and Wetlands Department. “These regulations may require that certain pollutants are limited in the stormwater that discharges from the construction site.”
These varying tiers of stormwater regulations can make the permitting process especially difficult for builders with projects in multiple locations, or in more than one state. According to the NAHB, these regulations are not always coordinated or consistent, which can cause confusion and make compliance difficult. Adding more difficulty is the fact that stormwater regulations continue to evolve and are constantly being refined.
“Many builders understand and relate to clean water, but they don’t necessarily understand everything that may or may not be required of them when it comes to stormwater compliance during construction,” says Rountree. “There is a great need for training, both for builders and regulators in this process.”
In order to help understand stormwater regulations and navigate the stormwater permitting process, the NAHB has developed educational material and resources for builders. The NAHB’s Stormwater Compliance Cards provide information on stormwater generalities and what types of requirements are common through each jurisdictional level, while its Stormwater and Erosion Control Toolkit helps educate Home Builders Association staff on current regulatory trends in stormwater and assists them in participating effectively in local stormwater issues.
“In addition to navigating the permitting process, there can be many measures that builders need to take on the construction site to ensure compliance,” says Rountree. “We try to provide guidance on erosion protection and common housekeeping practices that is simple and straightforward.”
More Regulation Coming
The rules surrounding the EPA’s new proposed Effluent Limitation Guidelines for construction sites will be finalized in December of this year. ELGs are technology-based standards that will be added into National Pollutant Discharge Elimination System stormwater permits, adding more complexity into the existing regulation. The NAHB is working with the EPA in providing comments on the proposal. “The new rules will apply to all construction activities in the 50 states and set a technology limit that will become part of all future stormwater permits for construction,” says Rountree. “Although details of exactly what will be in the rules will not be made clear until the end of the year, we expect them to be very expensive and very stringent.”
In addition to the proposed ELGs, later this year in May, new Massachusetts Department of Environmental Protection and Environmental Protection Agency stormwater regulations for the NPDES and the TMDL programs will be implemented in Massachusetts, requiring builders and developers to use improved stormwater management techniques on impervious surfaces. These new requirements apply to both new and redevelopment, but most significantly they will require private owners of existing large impervious surfaces (including institutions, commercial, industrial and residential properties) to manage stormwater. Similar programs are expected to follow soon thereafter in Maine and New Hampshire, to a lesser degree. According to Dr. Robert Roseen, director of the University of New Hampshire Stormwater Center, new stormwater regulations similar to these are likely to be seen elsewhere across the nation if they prove to be effective.
“These regulations represent the extreme example for stormwater requirements, but in general, most other states are moving in this direction,” says Roseen.
“They are very stringent and are designed to greatly reduce contaminant loading in runoff to meet TMDL requirements. These standards simply cannot be met with most conventional stormwater management practices.”
The new Massachusetts regulations will apply to impervious surfaces on new developments and redevelopments that are five acres or greater. Existing developments throughout the state will also be required to come into compliance under the same conditions over 10 years. However, for TMDL-impaired areas of the state, such as the Charles River watershed, the new regulations will apply to project sites that are two acres or more and will have even more stringent load restrictions—including, in some locations, as much as 65 percent phosphorous reduction.
“Builders and developers will be required to have stormwater professionals approve and stamp their stormwater site designs prior to issuance of building permits, much in the same way that geotechnical professionals need to sign off on project sites,” says Roseen. Additionally, they will be required to annually certify maintenance compliance for these stormwater controls.
Low Impact Development
In keeping with the new EPA regulations, as well as other mandates, builders and developers are increasingly being required to meet much higher standards of stormwater management that simply cannot be met through conventional stormwater practices. As such, Low Impact Development is becoming much more prevalent. LID is often an innovative and highly effective approach for managing stormwater runoff that includes controlling precipitation as close to its source as possible. Common LID designs include rain gardens, bioretention, permeable pavers, grassed swales, vegetative strips, eco-roofs, rain barrels and cisterns. These strategies work to replicate a site’s predevelopment hydrologic conditions in order to manage stormwater more naturally.
“With properly implemented LID planning, the hydrological impact on a site is minimized,” says Roseen. “Stormwater is controlled, and instead of focused and concentrated runoff, water is allowed to infiltrate into the ground across the whole site in a more uniform and natural manner.”
According to the NAHB, LID can often provide good opportunities to homebuilders because grading, infrastructure and stormwater management costs can be reduced. Additionally, the environmental footprint of the project is lessened, and builders can receive points through the NAHB Green Home Building Guidelines. “LID also benefits cities and areas prone to drought conditions, since infiltrating stormwater recharges the local groundwater instead of sending the water off to the nearest stream,” says Rountree.
With impervious surface taxes increasing in LID designs along with more stringent EPA stormwater regulations anticipated, Atlanta-based Eco Custom Homes president and founder Jeffrey Dinkle sees more market demand in the future for LID stormwater management designs such as grass pavers, bioswales, and pervious pavements. “Higher impervious surface taxes are providing motivation for property owners and builders to install these types of stormwater technologies,” says Dinkle.
Despite the benefits of LID, however, challenges exist. “Those challenges include the additional up-front planning required to utilize LID during and after construction, and local ordinances or building codes that inhibit the use of LID,” says Rountree. “There is also uncertainty over who is responsible for the maintenance of LID or exactly what maintenance is required and how it should be paid for after the home is sold. A lack of public understanding of the function of LID projects has led some homeowners to damage or destroy their effectiveness. For all of those reasons, NAHB believes that the use of LID during construction should be voluntary and market-driven.”
In some regions of the U.S. coping with sustained drought, stormwater management has taken on a different meaning. Instead of viewing runoff as something that needs to be controlled and treated before it is allowed to leave the project site, many Green-minded builders are recognizing the value of stormwater, and are advancing rainwater harvesting techniques and strategies for catchment, retention and reuse.
According to Dinkle, for complying with the city of Atlanta’s regulations, builders in the Atlanta region have traditionally installed simple stormwater management systems such as flow wells that consist of a gravel drainage pit that allows water to percolate into the soil. These regulations require that stormwater designs are engineered for 3/4-inch rain storm events for all impervious surfaces on parcels that are two acres or more.
However, because of ongoing drought in Georgia as well as the rising value of water in the Atlanta area, rainwater harvesting systems are becoming increasingly popular. These systems collect and store stormwater for reuse, mainly in outdoor irrigation.
“Why not invest a little more in a stormwater management system so that water can be collected and used for other purposes?” asks Dinkle. “With water becoming scarcer and more expensive, this makes the most sense. Currently, most rainwater harvesting systems are designed to use water for irrigation only. Local governments are not up to speed on using this water for inside the home. However, in a few years I think this will change, and it will become standard practice to use captured stormwater for flushing toilets and washing clothes.”
In building Forrest Manor, a 6,400-square-foot, high-performance Earthcraft estate in the Atlanta area, Dinkle installed a rainwater harvesting system with two 1,700-gallon underground storage tanks and a multizone sprinkler system for irrigating the home’s extensive native, drought-tolerant landscaping. For another residential project, Dinkle designed an under-deck rainwater harvesting system that captures rainfall from half of the home’s roofing, which is diverted to a 550-gallon cistern. The water from this system is conveyed to handheld spigots, which can be used for watering plants or washing cars.
In addition to rainwater harvesting systems, Dinkle believes in a few more years that constructed wetlands will become more popular. “If a builder is spending around $12,000 for underground cisterns, it makes sense to spend a little more to get something that can double as a landscaping feature,” says Dinkle. “This is the direction I will be going. Granted, constructed wetlands are not realistic for all sites, but overall they represent the best value, because they are aesthetically pleasing as well as practical for retaining rainwater.”
Builders and developers who put in constructed wetlands and other measures for capturing and reusing water can earn points toward certification with the U.S. Green Building Council’s Leadership in Energy & Environmental Design Green Building Rating System.
“However, in addition to obtaining LEED credits and other incentives, builders and developers who incorporate stormwater retention designs—especially in drought-prone regions or areas with less than reliable supplies—will have more control over their water quantities,” says Heather Kinkade, president of Forgotten Rain, a Phoenix-based consulting company dedicated to rainwater harvesting, stormwater reuse and rain garden design.
Kinkade, who works with builders and developers across the nation by aligning them with stormwater and rainwater contractors in their areas, says that water captured in desert and arid regions can be combined with other forms of water runoff to ensure larger quantities for reuse. “Dry regions like Phoenix only get so much rainfall throughout the year,” she says. “So it can be a good idea to combine captured stormwater with other types of alternative water sources that can be collected, such as condensate from air-conditioning units or blow-down water from cooling towers. Water from those types of processes is more consistent and can be excellent for irrigation.”
Rainwater events in desert regions can be very sudden and dramatic. For instance, although the average rainfall in Tucson is around 12 inches per year, it is not unusual for the city to receive an inch of rain in under an hour. Therefore, for harvesting water for reuse builders and developers should implement stormwater systems that work to slow down flow velocity and facilitate retention. “Harvesting systems should be designed for capacity,” says Kinkade. “Storm events in arid areas can be very infrequent and the runoff can carry a considerable amount of volume, so stormwater designs should be cable of capturing, conveying and storing floodlike waters.”
In Texas, Lewisville-based Green builder Chris Miles, cofounder of GreenCraft Builders LLC, says stormwater capture is becoming more and more important as drought continues to impact the South and Southwestern areas of the nation. “In my region of the state, approximately 50 percent of our overall water usage is dedicated to landscape irrigation,” says Miles. “So there is a big need for builders to design and install both above-ground and below-ground catchment systems. They can serve the dual purpose of controlling runoff as well as lowering a home’s usage of potable water, thus lessening the impact on public water supply.”
Rainwater harvesting was one of the many sustainable features for GreenCraft Builders’ Bannister High-Performance House, a demonstration project in Grapevine, Texas, for the U.S. Department of Energy that achieved a LEED Platinum certification. The house features a standing seam metal roof with 5,000 square feet of area and a 10,000-gallon cistern on the side of the home. One inch of rainfall is capable of collecting 3,000 gallons of water that can be used for irrigation and other uses.
“It’s important for builders to promote water conservation, especially with significant water shortages taking place in the Southwest,” says Miles. “We need to start thinking of water as a precious resource.”