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In the July/August issue of Onsite Water Treatment, we featured the first of a three-part series on how communities can use wastewater planning as an aid to managing growth. Our focus is on small towns in New England that are facing the dual challenges of providing public services to new residents while controlling how—and where—the community develops, a problem that is affecting small, limited-resource communities nationwide.
Among these communities, common goals include protecting potable water supplies and environmental resources that can influence a community’s way of life and sometimes its economic base. Our first article profiled Warren, a small village of 5,000 in Vermont’s Green Mountains. Failing septic systems in the historic town center sparked debate among residents about future development. Faced with the immediate wastewater crisis of failing onsite systems, Warren opted to limit growth and preserve its historic character with a combination of traditional and alternative decentralized wastewater technologies that was sized to its existing village center. In the course of the project, Warren built one of Vermont’s first alternative technology systems, helped raise statewide awareness of coordinated wastewater planning and was among the first communities to conduct a detailed needs assessment as a precursor to systems design. Project financing was provided through an EPA Demonstration Grant in tandem with an EPA State and Tribal Assistance Grant as well as State Revolving Fund monies. An elaborate program of public outreach was critical to achieving buy-in from town residents as well as state regulators skeptical of alternative technologies.
In coastal Rhode Island the challenge has been to manage development already under way while protecting finite drinking water supplies and environmental resources from future development that could endanger quality of life and threaten both property values and the tourism that in many cases is a basis for local economies.
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| An aerial view of northern Block Island shows the Great Salt Pond, the island's premieere harbor for recreational boating. |
The story begins in the upscale but progressive town of New Shoreham on Block Island, where the community used its share of a $3 million EPA demonstration grant (matched with $1 million in local funds) to develop a wastewater management program that could be shared with other communities. Included were a wastewater management ordinance, wastewater treatment standards that applied to new construction and replacement of failing or substandard systems and, like Warren, an extensive program of public outreach. The story continues in Jamestown, another Narragansett Bay community, which expanded on Block Island’s experiences to develop an overlay district in an area of high intensity development.
Factors that appear to have contributed to the success of these Rhode Island projects include the state’s proactive Department of Environmental Management, New England’s tradition of local control over land use, and guidance from the University of Rhode Island Cooperative Extension Municipal Watershed Training Program, which partnered with the town of New Shoreham and the two mainland communities of South Kingstown and Charlestown on the EPA project.
“The goal,” says South Kingstown planner Ray Nickerson, “was to manage local water quality from a watershed perspective.” The key was to expand the town’s perspective beyond the treatment and disposal capacity of individual lots to what would be necessary to achieve communitywide water quality goals. Eventually a combination of treatment standards, mandatory inspection and the application of alternative technologies solidified this watershedwide approach.
Land-Use Planning Legislation
As in other New England states, Rhode Island cities and towns have control of land use, rather than counties, which is more typical in other areas of the country. The system was problematic, however, during the boom of the 1970s and ’80s as many small cities and towns found themselves at a disadvantage when traditional zoning rules to protect public health, safety, and welfare proved insufficient. Communities couldn’t keep up with a growing demand for municipal facilities and services; environmentalists worried about loss of open space, particularly wetlands; and residents watched as the state’s aging infrastructure sagged and rural areas and wildlife habitat were randomly urbanized.
After a series of false starts, the state legislature passed the Comprehensive Planning and Land Use Regulation Act of 1988, which gave towns the power to control growth as long as they met state-mandated responsibilities for management. Towns were required to develop a comprehensive land use plan and review and update that plan at intervals of no more than every five years. The plans were required to contain a description of the community’s goals and policies pertaining to land use, housing, economic development, natural and cultural resources, services and facilities, open space and recreation, traffic circulation, and the town’s plans for implementation, including capital budgeting. Subsequently the 1991 Zoning Enabling Act and 1992 Land Development and Subdivision Review and Enabling Act of 1992 required towns to bring their zoning ordinance and subdivision review into conformity with their comprehensive plans.
“In the past,” says Lorraine Joubert, coordinator of the University of Rhode Island’s Cooperative Extension’s Nonpoint Education for Municipal Officials program (NEMO), “wastewater planning has been dealt with through facilities planning. Since zoning was a town’s means to implement its comprehensive plan, towns now needed to set sewer boundaries that were consistent with their urban growth boundaries.”
Another factor that contributed to the success of the Block Island Green Hill Pond demonstration project (formally designated the Block Island Green Hill Pond Watershed National Community Decentralized Wastewater Treatment Demonstration Project) was the enabling atmosphere fostered by Rhode Island’s Department of Environmental Management (DEM), the state’s central authority for regulating onsite systems. The department provided grants and technical assistance to towns, established standard procedures for septic system inspection, created processes to review and approve alternative technologies for statewide use, and instituted training and certification programs for system designers, site evaluators, installers and inspectors in cooperation with URI’s New England Onsite Wastewater Training Center.
To Each According To Its Need
According to Joubert, the partnership between the island town of North Shoreham and the two mainland towns of Charlestown and South Kingstown under the umbrella of the EPA grant was forged in the shared aim of maintaining groundwater quality, directing development to already sewered areas, and limiting growth in areas of marginal soils and in proximity to valuable natural resources.
In Charlestown, which is totally dependent on groundwater from private wells, small summer cottages have been converted into larger, year-round homes, and bacterial contamination resulted in a number of prohibitions against harvesting shellfish from local waters. Similar conditions applied in neighboring South Kingstown. The population in both towns has increased significantly in the past 10 years, South Kingstown by 13% to nearly 28,000 residents and Charlestown by 21% to 8,000 residents. When the project was initiated, South Kingstown was discharging some 300 million gallons of wastewater a year from 6,600 onsite systems and cesspools. In addition, housing in the Green Hill Pond Watershed on the border of the two communities had been built on poor, excessively drained soil that promoted the movement of pollutants into the pond and underlying groundwater. These conditions contributed to the accumulation of the bacteria that resulted in the pond closures and in the excessive nitrogen inputs considered responsible for overfertilization of coastal ponds generally. In these poorly flushed ponds, even small increases in nitrogen loading can result in excess growth of nuisance algae that leads to the loss of eelgrass and to the degradation of habitat for fish and shellfish.
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| An aerial view of southern Block Island reveals the many freshwater ponds and wetlands sensitive to deleopment and onsite wastewater discharges. |
The goals of the Block Island Green Hill Pond demonstration project were to establish wastewater management districts within the three communities, to emphasize mandatory inspection and maintenance, to develop and implement comprehensive education outreach programs for the town’s staff, citizens, onsite system designers, and wastewater haulers, and to install and monitor alternative onsite technology. According to plan, the town of New Shoreham would be on a fast track to model what other communities might accomplish. Block Islanders were known to be conservation-minded and early adopters. New Shoreham had its own Geographic Information System and had purchased land on the island to set aside for open space. The community had also commissioned a USGS hydrogeologic investigation (which noted that the availability of drinking water on the island as was directly related to the volume and quality of wastewater effluent discharged by onsite systems) and had updated the town’s comprehensive plan to include the specific goals of maintaining existing high-quality drinking water and establishing wetland buffer regulations in excess of state wetland setbacks. The town’s plan also called for limiting growth in its already developed core to avoid sprawling in outlying areas.
Block Island is 6,400 acres of layered sand, silt, and clay 10 miles off the central Rhode Island coast. The island is a popular vacation spot that annually accommodates a large seasonal influx of residents and visitors. The year-round population of 800 amounts to a meager 86.2 residents per square mile, but in summer the population can jump to 10,000 with day-trippers adding another 3,000. The characteristics of the island’s surface geology results in high variable permeability and unpredictable flow paths. Subsurface freshwater supplies occur in shallow lenses ranging from 4 to 40 feet thick (compared to mainland groundwater aquifers where saturated thickness is typically 100-150 feet or more).
Much of the island is currently zoned at one dwelling unit per 3 acres, but much smaller grandfathered lots exist. In the Great Salt Pond watershed, 22% of developed lots and 41% of undeveloped lots are smaller than 20,000 square feet. Only the town core is sewered, and overall 85% of year-round residents and 54% of summer residents use onsite wastewater treatment systems. Private wells are used by 93% of year-round residents, while a town public water system serves the harbor commercial area (where 70% of water demand occurs in the three months between June and August). The island’s finite water resources are vulnerable, including an EPA-designated sole source aquifer, the 950-acre Great Salt Pond coastal embayment and public wellhead protection areas.
Step One: Watershed Assessment
New Shoreham first addressed wastewater management in 1995, in part because of concerns for the island’s aging septic systems. Continued growth’s potential impact on water quality was also an issue, especially the development of substandard lots clustered around fresh and saltwater ponds. Since New Shoreham’s comprehensive plan called for avoiding sprawl, extending the harbor area sewer system was not an option, and the town had to decided how it was going to accommodate development.
According to Joubert, the risk-based wastewater management program New Shoreham eventually implemented dates back to the 1980s, when innovative onsite technologies were first used in Rhode Island coastal watersheds to protect or restore poorly flushed nitrogen-sensitive coastal waters. After a failed attempt to adopt a water quality protection zone for the island’s surface waters, the town planning board focused on correcting failing and substandard onsite systems and evaluating potential threats to the island’s water resources. The eventual result was a septic system inspection ordinance and subsequent development of wastewater treatment performance standards that were adopted within the town’s zoning ordinance.
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| This typical Block Island scene of open fields and stone walls and traditional island architecture actually shows modern development using creative designs of conventional onsite wastewater treatment systems to mirror historical land use patterns. |
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| This coastal salt pond and others strung along the south shore of Rhode Island are highly valued as recreational resources. |
Joubert’s group at URI undertook an islandwide needs assessment using the cooperative extension’s MANAGE Model (Method for Assessment, Nutrient-loading and Geographic Evaluation of Watersheds), which uses computerized maps and other easily available local data to identify and display high-risk areas for pollution movement. The model was applied to the entire town but included separate analysis for each of seven critical resource areas identified as priorities for protection, including surface water reservoir watersheds, public wellhead protection areas and the Great Salt Pond coastal embayment. The study also used current zoning to do a build-out analysis that compared relative changes in pollution risk related to future development and where alternative wastewater technologies were used.
Fundamental to this assessment was the effort to summarize existing information about natural features that affected the suitability of individual sites for onsite treatment systems. Soils with seasonable high water tables were found to occupy 27% of the island and extremely permeable soil 33%, circumstances that posed the risk of inadequate effluent renovation if conventional onsite systems were used. A vulnerability matrix was developed that included such site-specific characteristics as depth to the seasonal high water table, impervious soil layers (soils with a percolation rate equal to or slower than 40 minutes per inch), restrictive layers (soils with permeability equal to or less than 0.2 inches per hour) and excessive permeable soils (soils that have the potential to contaminate groundwater because of limited pollutant removal capability due to rapid drainage). From this a matrix of individual site vulnerability was established.
“The wastewater management plan is a basic needs assessment that identifies where the problems are and what the site constraints are,” says Joubert. “Many towns then find they need to go beyond this to investigate impacts from onsite systems. If you’re in a drinking water supply watershed, for example, you may have to have an advanced treatment system when you repair a cesspool or if you’re building a new system. But this may also depend on whether you’re located within a wetland buffer or what the soils are like and what the depth to water table is. Obviously, for substandard lots of record a town might have to grant a special use permit, but this also allows them the opportunity to mitigate impacts.
“Needs assessment is an ongoing process in that, as resources become available, more work can be done to identify the causes of problems and to develop solutions. We’ve found that stormwater control is another key issue along with wastewater management. Because Green Water Pond was impaired, for example, there was a lot of state-sponsored research done to establish total maximum daily loading (TMDL). One thing they found was that stormwater was contributing to bacteria contamination.”
The site-specific wastewater treatment performance standards specified in Block Island’s vulnerability matrix were eventually included in the town’s wastewater management ordinance. Treatment Level 1, for example, specifies conventional treatment but also requires a tested and certified watertight septic tank, watertight access risers to grade, effluent filter, and tipping D-box. Treatment Level 2N (for nitrogen reduction because onsite systems were found to be responsible for 72% of the nitrogen entering recharge waters) includes the same tank improvements—certified watertight tank, watertight access risers to grade, effluent filter, and tipping D-box, if feasible—plus effluent BOD and TSS concentrations of less than 30 mg/l along with greater than 50% TN Removal and TN concentration off less than 19 mg/l. Treatment Level T2C (pathogen removal) includes all T1 requirements (effluent filter and tipping D-box as feasible) plus effluent BOD and TSS concentrations of less than 10 mg/l, and fecal coliform concentration counts of less than 1,000 per 100 ml.
Because it was likely that inspections called for in the ordinance would turn up failed and substandard systems, town officials wanted to provide guidelines for the application of both conventional and alternative systems to ensure they would function properly on difficult sites and provide additional effluent treatment in the island’s designated critical areas. Treatment Level 1, for example, basically allows conventional treatment using a standards septic system with the tank improvement listed (technologies that Joubert notes are typically available although in practice, although most T1 systems are conventional). T2N standards for nitrogen reduction recommend T1’s basics plus a nitrogen-reducing system approved by the RIDEM through the Technical Review Committee process. Currently, systems achieving 50% removal and 19 mg/l TN reduction are approved as nitrogen reducing. These include either a RUCK system (older technology, not typically used any longer), recirculating sand filter, recirculating textile filter, FAST system or composting or incinerating toilet (in which case timed-dosed pressurized shallow narrow drainfields would handle the graywater component). Treatment Performance Standard 2C for pathogen reduction combines the basics with a single-pass peat or sand filter or composting or incinerating toilet with the same graywater drainfield treatment for improved pathogen reduction. With Treatment 2S, shallow pressurized drainfields or bottomless sand filters are generally used with T2 systems, which are required where the soil suitability rating is poor, the site vulnerability rating is high or extreme, or where the proposed system is in a wetland buffer or constraints exist that would significantly influence wastewater treatment and system performance and longevity.
The ordinance further specifies that all alterations, new construction and major repairs must conform to Treatment 1 or 2 standards as appropriate, that existing cesspools had to be upgraded to appropriate T1 or T2 standards, based on location, by 2005, that hydraulically functioning onsite wastewater systems had to have septic tanks retrofitted with access risers and effluent/screens by the same deadline, and that all septic tanks must be field tested and certified watertight by the manufacturer.
For new construction, the ordinance maintains a 150-foot town buffer from an onsite system to a freshwater wetland or coastal feature and a 200-foot buffer to a water supply reservoir. The ordinance also requires maintenance contracts for any onsite system that includes mechanical components. For new construction the ordinance prohibits the use of 4x4x4-foot galley leaching chamber drainfields and can require site-specific flow studies for subdivisions, land development projects and onsite systems generating more than 900 gallons of wastewater per day. Residents who think their property should be exempt from provisions of the ordinance must prove loss of all beneficial use of the property as a result of compliance.
As with Warren, VT, extensive public outreach was required to secure public support. “One initial stumbling block,” says Joubert, “was that this was an additional layer of bureaucracy that was intrusive and would cost too much over the long run.” But arguments about protecting the island’s existing drinking water resources were persuasive, especially since high-quality drinking water was considered a tourism draw. Another positive was that once a town has secured state approval of its wastewater management plan it qualified for a 4% interest rate on Community Septic System Loan Program loans to homeowners for onsite system repair. This, says Joubert, made a large difference in making the program more palatable to homeowners.
Jamestown’s Margins
Jamestown, RI, is a community of approximately 6,000 people who live on 6,185-acre bedrock Conanicut Island, which is connected to the mainland by bridge. Rainfall is the exclusive source of the island’s drinking water, and regular seasonal droughts, coupled with continued growth and development, have led to water quality concerns, particularly in Jamestown Shores, an area of high-density development.
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| Backyard tours conducted by URI's New England Onsite Wastewater Training brought state and local officials from the New England region to learn firsthand about alternative technologies installed as demonstration systems under the Wastewater Demonstration Project. |
Forty-three percent of the island’s residents rely on water from the Jamestown Water District, which draws from two surface reservoirs. Those who live outside the utility’s service area depend solely on private wells. Almost three quarters of Jamestown’s residents rely on septic systems, and because it generally has low-density zoning and sewers in most densely developed areas, the town’s fundamental concern has been development on substandard grandfathered lots. In Jamestown Shores, where the average size lot is 16,000 sq. ft., the situation is complicated by poor spoils and a high seasonable water table. Localized flooding, failing systems, private wells running dry, and salt-water intrusion have been problems in this area.
In conjunction with the Rhode Department of Health, URI undertook a source water assessment and wastewater analysis using the same MANAGE model it had used in New Shoreham. The study surveyed all of Jamestown’s open lots and those available for development. Using nutrient loading as a measure of pollution, it assessed relative pollution risk plus runoff under current conditions and at full build-out. Not unexpectedly the analysis identified Jamestown Shores as the island’s hot spot. The area topped the scale in terms of number of onsite systems per acre, amount of impervious cover, intensive land use, nitrate-to-discharge and phosphorous-to-surface runoff. To address the situation, the town took URI’s advice and developed a high water table and shallow impervious layer overlay district. An important goal for the area included controlling the volume of stormwater runoff. The town also aimed to maintain groundwater nitrogen at safe concentrations for private wells, to ensure septic system operation to provide adequate pathogen treatment, and to require use of advanced treatment systems where necessary in tandem with adequate
maintenance.
“It was really URI’s innovation that got us into the situation we were in,” says Jamestown planner Lisa Bryer. “They helped develop alternative onsite systems and get them permitted for retrofitting existing systems. But when these alternative systems started being used for new homes, it put the town in the situation where we had lots open up for development [of areas] we always assumed were not developable. If the property owner could get an onsite permit from the state, we had to let them develop. Because our normal zoning handles only building lot cover, we decided we had to look at minimizing onsite impacts by limiting impervious cover, and since our combined wastewater/stormwater ordinance went into effect in 2003, we have reduced total impervious cover on new development by approximately 50%.”
Jamestown is the first town in Rhode Island to combine specific stormwater and wastewater standards and to implement performance-based treatment standards in an overlay district. As part of its wastewater management program, the town tracks the operation and maintenance of advanced treatment systems and is the first Rhode Island community to use a Web-based tracking program. On the docket is an access riser and effluent filter retrofit/rebate program, routine maintenance inspections, and the tackling of enforcement issues. One lesson learned, says Jamestown wastewater specialist Justin Jobin, is that towns have to be proactive in permitting and developing their own restrictions and requirements, so like Jamestown they don’t get caught relying on whether or not a landowner can get an permit from the state that allows them to develop.”
Other Lessons Learned
Unlike Warren, VT where the new town wastewater system was designed to hold down development in its village core, the goal of these Rhode Island communities has been to manage new development by managing the wastewater infrastructure. In such cases, careful evaluation of future trends is critical.
Developing wastewater management programs that are expected to also help manage growth requires its own style of planning. At a March 2006 URI-sponsored workshop, South Kingston planner Ray Nickerson told New England civic officials the first step is to become up-to-date on legislation regarding land use, zoning and wastewater management. Next, a community’s local comprehensive community plan should specifically support whatever onsite wastewater management program is developed. Next, as a basis for the program, all available technical information on current systems should be collected in a risk assessment plan, which, as Joubert points out, will likely form the scope of any additional scientific investigations that might be required. This combined information should then be used as the basis for developing the town’s wastewater ordinance and should be included in its findings section.
Nickerson also observed that a number of issues will predictably arise around townwide wastewater management programs. Before putting a program before the public, town governments should consider what is likely to be politically palatable within the community and anticipate the need for compromise. Public education should begin early, he says. Elements of a sound public education campaign include fact sheets that outline what’s being considered, articles in local newspapers, workshops and meetings with residents plus professional seminars. The costs of the program being proposed should be discussed with elements of city or town government as well as residents. Nickerson stresses the importance of being clear about why the program is necessary; examine the short- and long-term costs of “doing nothing,” he says. Be sure residents know what to expect and how the proposed program will come about. Finally, Nickerson advises, develop a realistic financial assistance strategy that details what the program will cost and how it will be paid for.
Penelope Grenoble O’Malley specializes in environmental topics.
OW - September/October 2006 |
