August 2010, Vol. 22, No.8

Growing Graywater Use Will Likely Have Little Effect on Reuse, Report Says

For years, a small but dedicated cadre of enthusiasts has championed the use of graywater — untreated wastewater from sources other than toilets and, generally, kitchen sinks — as a means of conserving limited water supplies in arid environments. Typically, interest in the use of graywater peaks during periods of drought, only to decline once the drought subsides. However, could increased use of graywater have negative consequences for water and wastewater utilities, particularly those engaged in efforts to promote water reuse? The answer is, “Probably not,” according to a recently released report commissioned by the Water Environment Federation (WEF; Alexandria, Va.) and two other associations. Even though the use of graywater may increase in drought-prone locations, the report finds, such an increase is not expected to have a significant effect on utility operations.

Released this past April, the report, White Paper on Graywater, was prepared by Bahman Sheikh, an independent consultant based in San Francisco who specializes in water reuse. In addition to WEF, the report was commissioned by the WateReuse Association (Alexandria, Va.) and the American Water Works Association (AWWA; Denver).

 

Responding to Growing Interest
In recent years, the use of graywater for irrigation or other purposes has received increased attention in certain regions of the country. For example, the California Building Standards Commission last year approved new standards pertaining to the construction, installation, and alteration of graywater systems for indoor and outdoor use in residential occupancies. More permissive than the state’s original rules, the revised standards are intended to facilitate increased use of graywater in the state. At press time, legislation (SB 518) pending in the California Senate would require the Building Standards Commission to adopt similar standards for commercial and industrial buildings.

With graywater receiving greater attention in California and a handful of other states, WEF, AWWA, and the WateReuse Association decided to pursue the white paper in order to obtain the most current information on the topic. “A growing interest in graywater in many of the regions where water reuse is common prompted” the board of directors of the WateReuse Association to commission the document, said Caroline Sherony, program manager for the WateReuse Research Foundation (Alexandria). The goal was to provide members the “most updated information on the subject” of graywater, Sherony said.

Despite a growing interest in graywater in different regions, little reliable information was available on the topic, said Don Vandertulip, a principal at CDM (Cambridge, Mass.) and chair of WEF’s Water Reuse Committee. “The lack of significant technical literature easily retrievable led us to commission the white paper as an information tool for our collective utility members,” he said.

 

Anticipating More Graywater Use
Because of population growth and migration patterns, “future water scarcity is almost universally expected to worsen in the arid and semi-arid regions of the world,” according to the white paper. In some cases, graywater can be used to meet roughly half of the landscape irrigation needs of an average detached residential unit, according to the report, creating significant incentives for residents to pursue graywater collection and use. “Even without encouraging or permissive legislation, the motivation to utilize household graywater becomes stronger as awareness of water shortage and of looming scarcity increases,” the report states. “It is expected that these influences will push graywater reuse to its logical limits over the coming decades.”

However, multiple factors will likely preclude widespread adoption of graywater as a water source, the report notes, even among states that do not prohibit the practice. In many cases, existing residential plumbing systems cannot be modified to separate graywater from so-called “blackwater” — that is, wastewater from toilets. Moreover, even in cases where residential plumbing can be modified to permit the separation of graywater, “this task is neither simple nor inexpensive,” according to the report.

 

Assessing the Likely Effects
For these reasons, the “quantitative impact of increased graywater reuse on the water reuse industry is expected to be modest, even under the most aggressive growth assumptions,” the white paper states. On the one hand, according to the report, “much of the growth” in the use of graywater likely will occur in areas that lack collection systems and, therefore, do not engage in the practice of wastewater reuse. On the other hand, residents of regions in which the reuse of treated wastewater is a common practice are less likely to experience much interest in pursuing the use of graywater, Sheikh said.

In the past, concerns have arisen whether increased use of graywater could reduce flows in collection systems, impairing their ability to transport solids. However, such concerns are likely unfounded, Sheikh said. “It would take a particularly low-sloped, narrow lateral sewer serving a cluster of homes all using graywater for the flow reduction to affect the ability of the sewer to carry solid matter efficiently,” he said. “My experience is that this is a relatively rare possibility and can be mitigated.”

 

Protesting the Color Purple
One issue related to graywater that has aroused concerns among water reuse proponents is the adoption by the International Association of Plumbing and Mechanical Officials (IAPMO; Ontario, Calif.) of the 2009 edition of the Uniform Plumbing Code, which requires the use of purple pipe or purple paint or tape on all pipe used to convey “alternate waters.” Defined as nonpotable water generated onsite, the category of alternate waters includes graywater, harvested rainwater, air-conditioner condensate, stormwater, and reclaimed water from onsite sources, Vandertulip said. Of the different types of alternate water, graywater is “by far the largest volume of onsite alternative water being discussed and used today,” he said.

Purple, of course, has long been the color used to designate pipe conveying recycled or reclaimed water. For this reason, some reuse advocates worry that a future problem involving graywater could be mistakenly associated with reuse water. Utilities that treat and distribute reclaimed or recycled water “have branded the use of purple pipe to designate that the pipe carries a high-quality treated water from a wastewater origin,” Vandertulip said. “Many of the public and especially the press associate the purple pipe with reclaimed water” from a utility, he said. If a cross connection were to occur on private property where purple pipe was used for one or more alternate waters, any resulting negative publicity “could damage 30 years of educating the public and acceptance of high-quality reclaimed water to supplement existing water supplies,” Vandertulip said.

However, others downplay such fears. Because recycled or reclaimed water must meet stringent treatment standards, entities involved with reuse “do not currently foresee any backlash to their product” as a result of increased use of graywater systems by homeowners in certain areas of the country, Sherony said. Reuse water is “viewed as a very different product from graywater,” she said. At the same time, the WateReuse Association, WEF, and AWWA have jointly requested that IAMPO discontinue the use of the color purple to designate pipe that is used to convey graywater.

For its part, the WateReuse Association plans to conduct a 2-year outreach effort that will involve conducting more research and data gathering, Sherony said, along with the development of a communication plan regarding the differences between graywater and reuse water.

Jay Landers, WE&T

 

Clean Water Costs Cape Cod Billions

Financial and implementation challenges shared by 15 Massachusetts municipalities to address nitrogen loading offer lessons for developing coastal regions currently running on septic systems

 

Cape Cod is truly Massachusetts’ share of paradise, with more than 943 km (586 mi) of tidal coastline that is largely uninterrupted by seawalls and structures. An economic engine of the state, Cape Cod’s $8.6 billion gross regional product, according to the U.S. Bureau of Economic Analysis, is in part due to seasonal population swells of 100% to 200%.

But lurking behind the majestic coastline are soils highly affected by nitrogen. Planners on the Bay State’s most famous of sandy peninsulas are faced with financing and coordinating massive wastewater treatment efforts, for an unprecedented public works price tag of $4 billion to $8 billion, according to Mark Forest, chief of staff for U.S. Rep. William Delahunt (D–Mass.).

“We’re in an era of remediation and restoration,” Forest said. “We’re dealing with the environmental mistakes of the past.”

Such high investment for underground and public infrastructure in a coastal region that frequently makes headlines for its notorious erosion damage is also begging questions. “Because of the high [costs], we are now having a bit more debate,” Forest acknowledged.

In addition to the challenge of financing wastewater infrastructure to address highly variable seasonal flows, local officials must integrate systems across municipal borders, educate the public, and manage opposition.

 

Sources of Impact
In the last 30 years, Cape Cod’s population has doubled. Nitrogen levels are extremely high throughout Cape Cod, eelgrass is dying, and shellfishing, an important Cape industry, is struggling.

“We’re dealing with cleaning up the residue of human existence,” said Paul Niedzwiecki, executive director of the Cape Cod Commission, one of two Massachusetts regional planning agencies with regulatory authority. “We can see that the degradation is happening.”

“Eighty-five percent of the controllable load is septic,” said Andrew Gottlieb, executive director of the Cape Cod Water Protection Collaborative (CapeKeepers), a regional governing body charged by Cape Cod county commissioners in 2005 to focus on education and outreach, as well as financial assistance, and to discuss capital projects. Tidal flushing is 2.4 m (8 ft) on the north coast of Cape Cod — the Massachusetts Bay side — and only 1 m (3 ft) on the south side, along Nantucket Sound.

There has been “significant precipitous decline,” Gottlieb said.

Gottlieb was assistant commissioner in the early 1990s, when the state Executive Office of Environmental Affairs and the University of Massachusetts (Amherst) School of Marine Science and Technology launched the Massachusetts Estuaries Project (MEP), enabling communities to undertake estuary evaluation at about 40% of actual cost.

The project provides water quality, nutrient loading, and hydrodynamic information for 89 estuaries in southeastern Massachusetts, including Cape Cod. MEP also includes a predictive model that provides information on water quality changes that result from land-use management decisions.

Fruits of a Flawed Growth Strategy
With roads built along the coast and houses built up to the edges, “we’ve done as many things that you can do to impede the health of a pond,” said Eric Turkington, former selectman and state representative. “We’ve blocked off the entrances pretty severely.”

Niedzwiecki attributed many of the problems to a movement on Cape Cod to discourage growth by maintaining smaller roads and avoiding sewer systems.

“That’s horribly flawed growth management,” Niedzwiecki said.

In addition, the Federal Groundwater Rule, which became effective in December, affects 200 public water systems on Cape Cod. The rule requires monitoring when a system identifies a positive coliform sample, and then corrective action and ongoing compliance monitoring for any system experiencing fecal contamination.

While there is no enforcement action yet, there are several areas of concern with septic bans or restrictions. Drinking water on Cape Cod is ground-fed from a sole-source aquifer. Many municipalities are planning drinking water system upgrades, including Provincetown, which is also expanding its vacuum sewer system dating from 2003.

The future of Cape Cod, an environmental treasure and a region of economic significance, will largely depend on funding assistance.

“The largest environmental threat is going to result in the biggest capital infrastructure project the cape will ever see,” Niedzwiecki said.

 

Financial Ebb and Flow
Explaining the costs to Cape Cod’s 237,000 year-round residents is no easy task.

Part of public officials’ job is to ensure that they can answer questions, Niedzwiecki said. “This is the necessary process that people go through when they’re asked to pay,” he said.

To date, Cape Cod has been allocated $29.7 million in U.S. Department of Agriculture (USDA) Rural Development Assistance (RDA) grants, $185 million in zero-percent loans from the State Revolving Funds (SRF) for wastewater and some drinking water improvements, and $30 million over 10 years from federal stimulus funds to implement the Cape Cod Water Resources Restoration Project — more than 76 projects that address “man-made improvements that need to be fixed,” Forest said.

Five million dollars in stimulus funds were allocated in early 2010, and according to USDA Natural Resources Conservation Services staff in Massachusetts, selection of specific ecosystem restoration projects, which include title restriction, fish passages, and stormwater discharge improvements, were announced in May.

They “are valuable projects, but none of that money is going to flow to wastewater infrastructure,” Gottlieb said.

“There’s no federal money out there,” Niedzwiecki said. “But the state has been there.”

In 2008, Massachusetts implemented zero-percent SRF loans, creating a $250 million subsidy over 10 years for nutrient management projects statewide, Gottlieb said.

On the outer midcape, Chatham, which recently received a $55.5 million SRF loan, “is leading the pack,” Gottlieb said. Provincetown received $9 million in RDA grants and a $3 million U.S. Environmental Protection Agency/Massachusetts Department of Agricultural Resources loan for vacuum sewer system expansion, and Falmouth is investigating expanding its system, as well as sewer alternatives, through its wastewater management planning efforts.

However, the region’s upwards-of-$8 billion price tag, which includes an estimated $675 million for proposed sewers in Falmouth and $300 million for Chatham sewer expansion, will affect every Cape Cod resident.

With seasonal influxes, “anything [we] build has to be able to accommodate peak flows,” Gottlieb said. “Every town on the cape needs to develop a wastewater management plan to think through long-term financing.”

“Today, looking at our needs, you can’t saddle all the requirements on local taxpayers,” Forest said. “There is no region of the country that has that great a need spread over such a small population base.”

 

Alternative Approaches
Falmouth, which covers 114 km2 (44 mi2), is actively studying alternatives for estuary cleaning, including ways to reduce runoff and natural methods to increase nitrogen absorption, such as using 45 town-owned acres full of bogs, marshes, and vegetation.

According to Turkington, a member of Falmouth’s Wastewater Plan Review Committee, some question whether sewering is the answer, which is based on the MEP data.

“The problem with it is the cost … $3 [billion] to $8 billion … that’s not sustainable,” Turkington said, noting that he believes state researchers are “grinding” individual estuary studies out.

“Some people just don’t like the answer,” said Gottlieb, noting that each MEP study includes 3 years of intensive water quality monitoring, land-use monitoring, and detailed bathymetry.

Looking at “expense-versus-needs” naturally leads to challenges to scientific data, Niedzwiecki said. “We’ve been through that with the science,” he said, noting that the experience is “polarizing ... you’re either a big-pipe person or a small-pipe person,” Niedzwiecki said.

Falmouth’s wastewater planning committee is looking pond by pond to see where opportunities lie, Turkington said. “Sandy soil, it just percolates beautifully,” he said. “It’s a blessing and a curse.”

 

Shared Infrastructure a Must

According to Niedzwiecki, the solution for Cape Cod is going to be in building shared infrastructure, because the estuaries and related nitrogen impacts do not adhere to municipal borders.

CapeKeepers published a study of the region’s watersheds in May. The study, based on geographic information system data, revealed how much nitrogen must be removed from each watershed, Niedzwiecki said.

“We’re going to have a real difficult time not overbuilding or not removing enough nitrogen,” Niedzwiecki said. “There’ll be large collection systems and smaller collection systems and alternative solutions in more remote areas.”

— Andrea Fox , WE&T

© 2010 Water Environment Federation. All rights reserved.