Estuarine impacts are in many ways a direct result of development patterns, and this is illustrated well in the most developed coastal region of the country — the Northeast, which contains 18 of the 25 most densely populated coastal counties (according to the National Ocean Service’s 50 Years of Population Change Along the Nation’s Coasts, 1960–2010). However, all U.S. coastal regions are experiencing rapid development. The nation’s coastal population is expected to increase to 127 million people by 2010, an increase of 60% since 1960.
A disproportionate amount of people — currently, half of the entire population of the United States, or approximately 110 million people — live on the coveted narrow strip of land that is just 17% of total U.S. land area. Continued growth on coastal lands poses major challenges, both in protecting the health of coastal water quality and in managing the nation’s important coastal resources. If the United States is to avoid destroying prized coastal resources, it is imperative that decision-making on the local level be improved, that innovation be properly encouraged, and that the environmental monitoring community and the water quality industry become better connected to decision-makers.
There is no one-size-fits-all prescription for water quality management in the United States. The federal government has empowered states to oversee dischargers while encouraging participation in developing regional management strategies and, on occasion, funding action plans to abate environmental impacts.
However, coalitions take time to build, projects need time to take effect, and what looks like striking progressive action at the federal level tends to have a trickle effect. Many of the people monitoring, managing, and developing support tools say that as a nation, the United States simply cannot keep up with the pace of development.
Though development comprises both residential and commercial projects, construction of housing may be an important indicator of sprawl, according to the National Ocean Service’s Population Trends Along the Coastal United States: 1980–2008. This report notes that from 1999 to 2003, coastal counties (there are 673, compared to 2470 noncoastal counties) issued 2.8 million building permits for single-family residences and 1 million permits for multifamily residences. Respectively, these figures represent 43% and 51% of the total building permits for the country during the 5-year period. Thus, roughly half of the housing construction in the entire United States was on the coast.
The report also notes that coastal counties permit the construction of at least 1540 single-family homes per day. They also permit commercial and necessary municipal construction that supports their growing communities.
Such growth equates to a significant reduction of natural lands, proposes changes to natural hydrology, and increases impacts to local waters. According to Nancy Wheatley of Nancy J. Wheatley Inc. Water Resource Strategies (Siasconset, Mass.), the greatest concerns to water quality in developing coastal areas are “the changes in runoff from the built areas, as opposed to the natural areas,” which include wastewater effluent, septic systems, and other wastes.
The Proof Is in the Zoning
Complicating land use decision-making are the economic needs of a community, and sometimes the pressure of motivated developers. According to the National Association of Home Builders’ (Washington, D.C.) Web site, housing is one of the “largest engines of economic growth in the country.” More than 1.9 million new homes will be constructed this year alone.
However, Wheatley, who provides strategic planning, regulatory review, project assessment, and advocacy, said it’s communities that need to decide what their values are. “It’s easy to blame developers going to the zoning board, but we live in a country based on free enterprise ... communities need to step up their zoning to manage community growth,” she said.
“In many ways we have a fragmented decision system between land use and zoning and health boards and conservation commissions,” said Martin Pillsbury, manager of regional planning for the Metropolitan Area Planning Council (MAPC), a regional planning agency representing the 101 cities and towns of metropolitan Boston.
Wheatley — an attorney who has served as director of technical services for the County Sanitation Districts of Orange County, Calif. (one of the most populated counties in the country), director of technical support and unit chief of wastewater engineering for the Massachusetts Water Resources Authority, and in other industry posts — emphasized the importance of educating local officials and developers. “We have to do a better job of educating people about how to minimize impacts to coastal environments,” she said.
According to Andrea Cooper, smart growth coordinator for the Massachusetts Office of Coastal Zone Management and the Executive Office of Environmental Affairs, in whose state sprawl continues, it is most often due to a lack of both understanding of alternative design approaches and technical capacity.
To minimize environmental degradation, planners can buy land for preservation, work to redevelop brownfields, add trees in urban areas, and implement low-impact development (LID) stormwater practices, which use biofiltration to remove pollutants and replenish groundwater and drinking water supplies, and smart growth techniques — development practices that aim to mitigate environmental impacts and improve resource management.
Cooper co-founded a coalition in 1996 known as the Green Neighborhoods Alliance, which received a 2004 EPA Environmental Merit Award in recognition of its work to reduce sprawl and minimize environmental impacts by drafting an Open Space Residential Development (OSRD) regulatory model and outreach program. OSRD is based on Conservation Subdivision Design, which focuses on open-space conservation via a four-step process: identifying areas for open-space preservation based on environmental and community priorities; siting houses to maximize views of protected space; laying out roads to minimize paved surfaces; and drawing lot lines.
Though revised zoning frequently lags behind progressive planning efforts (because a two-thirds vote generally is required to change local zoning ordinance) more than 30 communities in Massachusetts have adopted voluntary OSRD ordinances. According to Cooper, studies have shown that homes in OSRD subdivisions appreciate more than 12% faster than those of conventional subdivisions, and the National Association of Home Builders supports OSRD design because it is more cost-effective. OSRD developments and LID retrofits are beginning to appear in all parts of Massachusetts, and they are a success, she said. “If you mimic natural hydrology and protect terrain, you reduce environmental impacts and costs,” she said.
Changing Zones and Behaviors
“The motivation now is ‘how do we not only get the message out there, but how do we effect behavioral change,’” said Chris Coburn, Water Quality Protection Program director for the Monterey Bay National Marine Sanctuary. The NPS (nonpoint source) program, a partnership of 25 agencies and organizations that oversee California’s Monterey Bay, was established to address water quality impacts from urban, rural, and agricultural runoff and to prevent prohibited discharges from reaching sanctuary waters. The program has developed five action plans, and its successes include preventing 408,000 tonne (450,000 ton) of sediment from reaching the bay, ensuring an additional 200 ha (500 ac) of irrigation management, reducing detergent concentrations associated with Monterey restaurants, installing numerous urban runoff control devices, and establishing a program for growers to develop management plans for their properties. “The real success is we have focused the region on an issue that does not adhere to jurisdictional boundaries,” Coburn said.
Cooper said the Massachusetts smart growth program uses a multilevel approach to reach out to and assist local communities with making changes. At times, she works directly with local decision-makers. Cooper also sets up regional technical assistance teams composed of watershed associations, regional planning agencies, and consultants that are well-positioned to provide local officials with the advice and technical assistance necessary to improve local ordinances and make better development decisions. Regionally, she works with large organizations to assist groups of communities in critical watersheds and estuaries.
While some communities are not interested in smart growth outreach, many are, and the Bay State smart growth programs are working hard to keep up with demand. Cooper feels confident that progress will continue, particularly through LID efforts. In response to those who fear that we cannot keep pace with sprawl, Cooper said she wouldn’t put the time and dedication to the problem if she thought the problem was insurmountable.
What communities need are resources, education, and assistance, Wheatley said. “The solution is going to be at the local level,” she said, noting that to gain public support, real progress must be demonstrated. “If you begin to solve problems, and the local community sees water quality improvement, the community becomes enthusiastic.”
The challenge is getting access to educate more local decision-makers. “We’d have far more real change if we had more people working directly with communities,” Cooper said.
The Merrimack Example
In the most developed areas, such as the Northeast, coastal storms cause impacts such as the May 2006 flooding in Essex County, Mass., and the Lower Merrimack Valley Watershed (the event was designated a national disaster).
The effect that developed areas have on estuaries like the Merrimack River’s can be demonstrated in a satellite photo taken May 18, 2006. The plume, though mixed with sediment, is exceptionally pronounced. The concern with plumes like this one, according to Alan Macintosh, assistant director of the Merrimack Valley Planning Commission (MVPC), is the elevated level of bacteria generated from runoff and other nonpoint sources.
The denser urbanized areas in the 15 MVPC communities (some formerly industrial) are significantly developed — about 70% to 80%, according to Macintosh. The region is a mix of urban, rural, and suburban land use. MVPC is projecting an 18% to 19% population increase by 2025, when the region is expected to reach 93% of its full development potential (under current zoning), Macintosh said.
The good news is that several of the MVPC communities have adopted OSRD bylaws. “A majority of the development proposals are coming in with these design principles, rather than traditional subdivision development,” Macintosh said. “And that has better implications for water quality.”
However, storms such as the May 2006 event, even though it was a rare 40- to 50-year storm, will still have their impact. “To significantly mitigate those impacts would require extensive, costly retrofitting,” Macintosh said. MVPC is focusing efforts on brownfields redevelopment (it recently received two sizable EPA grants for this effort) and LID to rein in existing NPS sources. “We are really beginning to bring attention to maximizing use of existing land,” Macintosh said, noting that he also is working with the state’s smart growth programs to set up an LID workshop for MVPC communities later this year.
Cooper said that there has been a lot of response to Massachusetts’ smart growth programs by the MVPC communities due to the recent flooding. “It woke people up,” she said. “People do not want this damage to happen again,” she added.
Hard-To-Handle NPS Sources
Sources of NPS pollution along the Merrimack are many; however, septic systems are prevalent in several of the 15 communities, but it is not known which areas are problematic. “Clearly there is an issue in some locations,” Macintosh said, noting that much of the region is not ideal for septic systems, because it is composed of largely till and marine clays.
Macintosh also noted that shellfishing at the mouth of the Merrimack’s 29-km-long (18-mi-long) estuary used to be a key industry — about 100 years ago. In addition to its estuary eutrophication analyses, NOAA evaluated all 3000 U.S. shellfish areas as part of its 1995 National Shellfish Registry. The majority of shellfish bed closings were indeed due to a high level of fecal coliforms.
In areas where nitrates are an issue — such as in communities that currently enjoy a strong local economy in shellfishing — nitrate analyses are often required before septic plans are approved. Local boards of health typically review percolation tests for septic systems.
However, “even perfectly functioning septic systems are a problem in the coastal zone,” said Mark Racicot, manager of government services for MAPC. “They still put out nitrates.” Aging and leaking sewer laterals do as well.
Developers often propose septic systems in areas that lack public sewers, because they are the lowest-cost waste management method for new development. If soils and plans do not meet state requirements, many developers opt for private package treatment facilities, which homeowners associations manage. Though package treatment is becoming more common, some states, such as Kentucky, have decided no longer to permit them. “Package treatment facilities are essentially big septic systems, rather than little wastewater treatment plants. They are often not well managed or maintained,” Wheatley said.
Spreading the Word
Education is paramount for local decision-makers, developers, and homeowners, Wheatley said. “Get information to homeowners about properly operating and maintaining septic systems,” she suggested. “People don’t understand their impacts ... . It’s often the addition of all the little events, not the big events.”
The challenge, Wheatley said, is getting people to the table, “because if you are only preaching to the choir, you never get anywhere. The hardest thing is that you have to find those that aren’t interested and get them to listen.”
This is unfortunate, because “too many people focus on ‘end-of-pipe’ solutions while there is so much we can do to better plan for and forestall the effects of development,” Macintosh said.
— Andrea S. Bistany, WE&T
About This Series
This is the second of a two-part series on the impact of coastal development on water quality. Part 1 of this series (August 2006 issue) examined current coastal conditions, coastal policy and management, and sources of impact.
Managing for More Frequent Storms
The spate of hurricanes that has hit North Carolina during the last 10 years left behind ecological effects that lasted long after flood waters receded, according to a study by marine scientists from the University of North Carolina–Chapel Hill and other institutions. These findings, the authors said, give water quality managers another thing to worry about with forecasts predicting that the recent uptick in storm frequency and intensity could last for some years to come along the U.S. East and Gulf Coasts.
Eight hurricanes ranging up to Category 3 have ravaged North Carolina’s coast alone between 1996 and 2005. Effects such as enhanced growth conditions for potentially harmful algae, low oxygen levels in bottom waters, and declines in some fisheries lasted as long as 2 to 3 years after such storms as 1999’s Hurricane Floyd, said Hans Paerl, a biological oceanographer at the University of North Carolina’s Institute of Marine Sciences (Morehead City, N.C.). He’s the lead author of the research report to be published this fall in a special issue of Estuaries and Coasts.
“With another above-normal hurricane season predicted for the North Atlantic this year, the study points to the need for adaptive ecosystem management approaches to accommodate these large-scale events over long time spans,” Paerl added.
The effects of storms that hit North Carolina’s coast varied substantially in magnitude and duration, the study found. Those that packed the biggest ecological punch, however, weren’t the highest category storms, but rather the ones that brought heavy rains and inland flooding, such as Floyd and 1996’s Hurricane Fran. For example, three sequential hurricanes, Dennis, Floyd, and Irene, sent volumes of sediment- and nutrient-laden floodwaters coursing into Pamlico Sound in the fall of 1999 that were approximately equivalent to 80% of the sound’s volume, according to the study.
That such 50–500 year flood events caused a larger nutrient enrichment and corresponding algal growth response than the “dry” storms didn’t surprise Paerl and his colleagues, “because we know that nonpoint source loading, which dominates nutrient input in North Carolina’s estuaries, is very much controlled by freshwater runoff,” Paerl said. What did surprise them was the extent and lasting effects of the responses.
Rather than flushing out the estuaries and Pamlico Sound of nutrients, these events led to a net increase in nutrients, largely because North Carolina’s semi-enclosed, poorly flushed estuaries and sounds tend to act as nutrient traps, Paerl explained. “Because of this, there was a nutrient memory effect of several years following, especially after Floyd, which delivered as much nitrogen and phosphorus to the sound as an entire year’s load.”
As a result, algae growth increased dramatically. “In the case of Floyd in particular, we had a period of at least a year of elevated algae growth in the Pamlico Sound and in the lower estuarine systems like the Neuse,” Paerl noted. “It took about a year for that to come back to what we think is normal.”
The flooding also led to incidences of vertical stratification, resulting in bottom water hypoxia and reduced dissolved oxygen concentrations, the study found. This, in turn, led to extensive fish and shellfish kills, as well as an increase in fish disease. Fisheries were depressed, and blue crab catches in particular remained below average for at least three years following Hurricane Floyd, according to the study.
“The good news is that, in general, fish health bounced back after this period of stress, but it’s also important to recognize that stocks of numerous finfish and shellfish species are more vulnerable to additional stressors, such as habitat disturbance and overexploitation during the period of post-hurricane induced stress,” Paerl said.
The massive amounts of freshwater runoff accompanying these storms transported large quantities of nutrients to the Pamlico Sound system, according to the study. Nevertheless, the researchers found that annual nutrient loads to the sound have gone down, largely in concordance with the recent upsurge in hurricane activity. Why this occurred is still a bit of a mystery.
“We don’t think it’s simply a flushing of nutrients, because if this had happened, we should’ve been able to account for them downstream in the Neuse Estuary or even Pamlico Sound through the ModMon and FerryMon monitoring programs, which were operating at the time,” Paerl said. (These are two long-term water quality monitoring programs supported by North Carolina’s Department of Environment and Natural Resources.) “In fact,” Paerl noted, “it appears that the watershed has given up less nitrogen after the large storm events.”
One explanation is that North Carolina’s nutrient management strategies aimed at reducing eutrophication in the sound and its estuaries are doing the job they were meant to do. Paerl pointed out, however, that the implementation of the state’s nitrogen reduction efforts closely coincided with the uptick in storm activity. Consequently, he said he believes other mechanisms are at work.
One possibility is that following the initial flush associated with Hurricane Fran in 1996, the watershed has become better at retaining the nitrogen being released in fertilizers, wastewater, farm manure, and other sources. Paerl and his colleagues call this the “sponge” hypothesis. In other words, the sponge was wrung out following the first storms and thereafter became highly effective in reabsorbing new nitrogen being applied to the land in the watershed.
Another possibility is that denitrification has increased in the watershed following storms and flooding events. “It’s well-known that standing water in ditches, swamps, and wetlands can lead to increased rates of denitrification,” Paerl noted. “Since these events generally occur after a bulk of the nitrogen has been applied to land or released as wastewater [in the spring and early summer months], the timing would favor this hypothesis.” However, he cautioned, both hypotheses require further testing and verification.
Implications for Managing Water Quality
Of course, none of this makes the job easier for watershed and water quality managers who are working to lower nutrient loadings from point and nonpoint sources during normal rainfall years, not to mention adding more frequent storm events to the calculation.
The primary tool for evaluating progress toward a nutrient reduction is trend analysis, noted Michelle Woolfolk, an environmental supervisor for North Carolina’s Department of Environment and Natural Resources. “One of the things you do in such an analysis is try to take out the effects of increased flow, which, of course, would occur with a hurricane,” she said. But now, “you’re talking about these outlier events becoming more normal, and that makes it much more difficult to remove the effects of flow in a good, scientific way; that’s a big problem.”
“This is something all water quality managers and scientists are struggling with,” admitted Holly Greening, a senior scientist with the Tampa Bay (Fla.) Estuary Program. “We’re working very hard to reduce nitrogen from many sources up in the watershed, and yet a single storm can come along and wipe out all your good reductions over time, if you looked at it on an annual basis.”
Tampa Bay, for instance, saw a considerable increase in sea grass acreage since efforts were made to reduce nitrogen in the early 1980s, Greening noted. Then, El Niño brought a very heavy rainfall in 1998, eliminating some of those gains. Since then though, the system has recovered and continued to see increases in sea grass cover, Greening said.
The lesson from the work in Tampa Bay is that “our long-term and extensive efforts in reducing nitrogen are providing a much healthier baseline that may allow the system to recover more quickly than if it were already heavily loaded with nutrients,” Greening added.
Paerl agreed. “There’s little doubt that [the state’s] nutrient reduction strategies and sedimentation controls have been helpful in minimizing nutrient enrichment and hypoxia potential of floodwaters associated with storms,” he said. But, “overall, hurricane cycles appear to be accompanied by large-scale, long-term changes in the manner by which nutrients are processed on impacted land and in receiving water. Nutrient management plans and controls need to incorporate the impacts of these cycles.”
— Kris Christen, WE&T