The Rural Crescent Workshop

On Saturday, December 7th 2013 Prince William County Office of Planning held an open house and all day series or meetings at George Mason University, Prince William Campus to discuss the results of the County Planning Department study of the County's rural preservation policies, an evaluation of their effectiveness, identifying additional rural preservation tools that may be appropriate and effective, and listen to citizen concerns and recommendations for amendments to the County's land use planning policies. There were four sessions: Rural Character, Land Preservation, The Rural Economy and an Open Discussion session with Chris Price, the Director of the County Office of Planning. Each of the sessions was repeated several times throughout the day to allow maximum access by the public. The Planning Office will be posting the session slides and discussion on the web if you missed the meetings. As anticipated the session presenters were topic experts, but I found many in the audience were very well informed and about the county policies, development, zoning and history. I encourage you to view the material from the sessions when it is posted on-line.

I was particularly interested in hearing the presentation of Dr. Tom Daniels a Professor of City and Regional Planning at the University of Pennsylvania. He had previously run the farmland preservation program in Lancaster County, PA and had studied and worked with several communities that had implemented successful and not so successful Rural Preservation Programs. His presentation focused on what tools exist for rural preservation and how likely they are to succeed. There is in reality a limited tool box for land preservation; most of these tools are based on partitioning land ownership rights. Owning land basically means owning a set of rights- the mineral rights, the use rights, the development rights, depending on what state the property is located, the water rights and the air rights. The development rights are controlled by zoning which we have discovered can be changed by the county supervisors by exception or amendment to the County Comprehensive Plan.

According to Prince William County records the Rural Crescent, established in 1998, encompasses almost 116,000 acres, that includes about 23,000 acres of federal land in the forest and Manassas Battlefield, 55,100 acres that are already developed including Quantico, about 2,600 acres that are permanently protected*(though permanently protected land can be seized for public use by eminent domain), 8,200 acres that have development plans already approved and almost 28,000 acres that are undeveloped and unprotected and could be preserved as open space and farmland. However, there has been continual pressure on the Office of Planning and the County Board of Supervisors to amend the zoning (to increase development density) for parcels in the Rural Crescent. The basic zoning in the Rural Crescent is A1- one house per 10 acres. So with the 8,200 acres with approved development plans, and the 28,000 acres undeveloped and unprotected there is a potential for 3,700 additional residences to be built in the Rural Crescent if it were to be entirely carved up into 10 acre parcels. The development rights in the Rural Crescent are the potential 3,600 homes.

The first land preservation option is essentially for the county or private party like the Trust for Public Land or another organization (the Piedmont Environmental Council does not define Prince William as part of their territory) to purchase or receive as a donation of a conservation easement the Development Rights to preserve as open space or farmland in perpetuity. The problem with the purchase of development rights is money. While the Commonwealth of Virginia has a farmland preservation program that provides funding to counties to purchase the development rights, the funding is extremely limited in the state. There is also federal funding under the 2008 farm bill (that will expire on January 1, 2014 and seems to include conservation programs in the latest versions of the Farm Bill that was sent Friday to the Congressional Budget Office to be scored. Even if the funding is maintained it only covers 50% the cost of development rights. Up to 25% can be donated land right value, but the rest must be paid for with cash.

There are several federal programs that have funding available to preserve farmland, forestland and ecologically important lands, but a county must have also have funding and staff expertise available to put together deals an navigate tax deductions and saleable state tax credits and work with organizations like the Department of Defense REPI (Readiness and Environmental Protection Integration) Program and the Trust for Public Land or the Piedmont Environmental Council to structure deals and pull together the funding to create a conservation easement or purchase the development rights. This takes a commitment on the part of the Board of Supervisors to fund and support such a program. I did not see a single member of the Board of Supervisors at the workshop.

The second preservation option is to transfer the development rights (TDR) to developments in other parts of the county that allow the developer to build a higher density than normally allowed. This was a strategy that worked incredibly well in Montgomery County where 7,000 TDR deals totaling $110,000,000 were done. Unfortunately, in Virginia the State does not allow the county to operate a “TDR” Bank and Prince William has only one remaining large development parcel that could have purchased a large number of TDRs, but that parcel is scheduled to have its zoning amended this summer. So essentially, it’s too late for the big deals and Prince William County would have to figure out a way to match development rights with small developments. The good news is that the Virginia legislature did pass the enabling legislation for that.

The final land preservation option is to cluster development with mandatory preservation of open space within the Rural Crescent. Cluster development is typically part of a low impact development strategy (LID). LID is the latest catch phase in ecologically friendly site development and consists of five elements: preserving open space and minimizing land disturbance; protecting natural drainage ways, soils and sensitive areas; incorporating natural site elements like wetlands, stream corridors, and woodlands as site features; reducing the size of traditional infrastructure; and decentralize and manage storm water at its source. While this is more protective of the environment (if you address the small group need for water and sewage management- clustered houses cannot have septic systems and wells and 5-10 homes may be too small a group to properly operated and manage a clustered on-site sewage treatment. Of the 345 farms in Prince William County (in 2007) 210 of them were 50 acres or less. LID is by its nature a distributed design involving, ongoing maintenance of the plants, replanting after severe winters or prolonged droughts, weeding, and other land and habitat maintenance along with effective water and sewage management. There does not yet exist a method of ensuring that these features are maintained appropriately and that any repairs or replacements are done with LID in mind.

It is a large challenge to preserve the Rural Crescent, but it is an extraordinary valuable resource that we need to maintain for our quality of life, the health of our watershed and the ecological services it provides. Protecting our water supply infrastructure is more than a pipe that runs into your house, more than the Occoquan. If you pave and build over the landscape the water supply will be irreparably damaged. Without water there is no Prince William County.

Sewers in America are Failing

In the United States there are estimated to be 600,000 miles of wastewater sewer lines; networks of pipes, pumping stations, and other equipment that move sewage from toilet and sink to wastewater treatment plants. Many of the oldest sewer systems dating from before the turn of the 20th century are still in service in our largest and oldest cities, and much of the sewer piping in the United States is original. As cities grew, the need for sewage and stormwater removal became necessary to protect human health. The oldest sewer systems were designed to carry both the stormwater and sanitary waste together in one system (to save money the sanitary sewers tapped into existing drain, storm and canal systems) to the nearest natural water body. Our rivers and bays had a limited capacity for dilution and as populations grew were overwhelmed by the sewage and became open cesspools of vermin, filth and foul orders devoid of all aquatic life. To alleviate the health hazards and disgusting pollution we began treating sewage waste. Until the 1960’s many sewage treatment plants only used screens and large settling tanks to remove solids and debris from sewage before releasing the effluent.

Today those steps are called primary treatment and all sewage treatment in the United States includes additional steps to ensure public health. Secondary treatments usually include biological and/or chemical treatment. One of the most common biological treatments is the activated sludge process; in which primary wastewater is mixed with bacteria that break down organic matter and cleans the water. Oxygen is pumped into the mixture. A clarifying tank allows sludge to settle to the bottom and then the treated wastewater moves on for tertiary treatment at advanced wastewater treatment plants. Coagulation, filtration and disinfection take place in tertiary treatment which also serves as a barrier to viruses, captures organics leaving secondary treatment, and precipitates heavy metals and other suspended particles.

The existing wastewater treatment systems in our cities cannot process the combined flow of stormwater and sewage and our cities struggle with solutions that they can afford. Some, like San Francisco have built a system of storage/transport boxes. The storage/transport boxes are huge underground rectangular tanks or tunnels that surround the City, the SFPUC describes them as a moat, a fitting image as the storage boxed ring the city. The storage/transport boxes catch the combined stormwater and sewage as it overflows the sewer system, but before it reaches the shoreline of the Bay or Pacific Ocean and hold the water until it can be processed. The storage/transport boxes in San Francisco have a total storage capacity of 200 million gallons and hold stormwater and sewage for later treatment at one of the wastewater treatment plants. 

In Washington DC, the Blue Plains sewage treatment plant is currently engaged in a $7.8 billion 20 year improvement program -the Clean Rivers Project adding a new stormwater storage tunnel that will hold 31 million gallons to the existing system storage for a total of 157 million gallons spread over the Anacostia River tunnels system and the new Blue Plains Tunnel. This will allow flow from the sewer collection system that exceeds the treatment capacity of the plant to overflow to the tunnel and be dewatered through a new enhanced clarification facility with a capacity of 225 million gallons a day. Retention basins, tunnels or storage tanks that can hold sewage until the water volume has eased or reconfiguring or expanding treatment facilities to increase maximum flow rates are capital intensive projects. Some cities like New York and Philadelphia, have targeted reducing stormwater flow using “green infrastructure” and low impact development strategies (LID) with BMPs (best management practices) to increase infiltration of rain and reduce the volume and velocity of stormwater.

In an existing city it is extremely hard to implement and maintain enough LID strategies to eliminate all excess stormwater flow and in NewYork City they are attempting to use the sewer piping system itself for additional storage by installing inflatable dams to block the flow of rainwater and sewage into New York Harbor in Brooklyn.  If the water pressure in the pipes gets too high, threatening to back up sewage into homes or onto streets, sensors are supposed to deflate the dam to release some water. It is a really interesting idea costing only $15.7 million for two inflatable dams, but runs the risk of increasing pressure on an aging sewer pipe infrastructure. No doubt this has all been considered and the inflatable dams are located in areas where sewer pipes have been replaced, relined or repaired. Effective storage volume increase will be 2 million gallons for each dam.   

No piping system can last forever and without continual maintenance, replacement and upgrade we have increasing instances of sewer pipe and system failure.  Failing sewer pipes can pose a significant threat to public health and the environment.  Systems with inadequate hydraulic capacity and/or blockages in the sewer pipes (not from inflatable dams) may lead to sanitary sewer overflows and sewage backing up into homes or onto streets. Untreated sewage potentially contains pathogenic microorganisms such as viruses, bacteria, and protozoa. Pipe failures can be caused by hydraulic restrictions (e.g. blockages intentional or caused by debris and fats, oil and grease buildups), hydraulic capacity (the pipe being too small for the flow), and structural condition of the pipes (failure due to deterioration).

Our growing and shifting population requires investment for new sewage infrastructure and maintenance and upgrade of the existing sewage infrastructure. In addition, current sewage technologies and management approaches may not be adequate to address emerging contaminants and health threats and are certainly not adequate to maintain reliable and sanitary sewage service to the 70%-75% of the homes and businesses that are on public sewers. The U. S. EPAhas estimated that if spending for capital investment and operations andmaintenance remain at current levels throughout the country, there will be ashortfall of approximately $270 billion  over twenty years for maintaining, replacing and upgrading our wastewater infrastructure, and no source of funding to make up the shortfall.

As Rose George author of the “Big Necessity” who has studied sanitation issues and practices around the world (and written a very interesting and engaging book), points out it is not a socially acceptable topic of conversation. She believes that may be one of many reasons why wastewater infrastructure is crumbling in the United States, despite its critical importance. Out of necessity (or eroding manners) the unspeakable is becoming more often spoken of. We can no longer ignore our sewage infrastructure. No infrastructure lasts forever and we have failed to properly maintain and plan for the orderly replacement of sewage collection and treatment systems. In the United States we have never experienced the need for pipe replacement on a large scale and have taken for granted what we were given. Now we need to find a way to maintain, improve and upgrade our sewer systems and wastewater treatment plants as they become essential components of our water supply systems because the United States has slowly and quietly begun to address the availability of water by recycling wastewater. Sewage is after all 99.9% water. 

Low Impact Development and Why it Matters

It has been called green infrastructure, conservation design, sustainable storm water design, natural stormwater management, and rain management but Low Impact Development, LID, seems to be the term that has taken hold in the United States for the site level actions and strategies. LID is a strategy of stormwater management emphasizing conservation and natural features combined with small scale stormwater controls to mimic as closely as possible the natural hydraulic properties of a site. The idea is to move water slowly through open conveyance systems and use distributed stormwater retention in open unpaved areas to allow infiltration of rain water into the earth. This reduces the quantity and velocity of stormwater as it leaves a site reducing the damage that uncontrolled stormwater runoff can cause when we change the amount of impervious surfaces a site has by building roads, sidewalks, playgrounds, and structures and compacting soil.

Traditional development practices cover large areas of the ground with impervious surfaces such as roads, driveways, sidewalks and buildings. These paved and impervious surfaces prevent rainwater from infiltrating into the ground, causing it to run off site at velocities and volumes that are much higher than would naturally occur. The collective force of such rainwater scours streams erodes stream banks resulting in large quantities of sediment and other pollutants entering streams, rivers, estuaries and bays every time it rains or snow melts. The US EPA believes that sediment and nutrient pollutions contained in runoff from urban areas is the largest source of water quality impairments to estuaries (areas near the coast where seawater mixes with freshwater) in the United States and has turned its water quality focus on these areas starting with the Chesapeake Bay Watershed and moving forward with the Gulf Coast estuaries.

Groundwater is recharged from rain and sources of surface infiltration. In many areas where development has occurred, we pump the groundwater for drinking water supplies (both public and private) and create barriers to rain infiltration by paving significant portion of the urban and suburban landscape as well as allowing if not encouraging storm water to leave a site as quickly as possible reducing the time that rainwater has to infiltrate the remaining soil and percolate into the subsurface. If we do not allow adequate rain water infiltration we will deplete the groundwater aquifers as we continue to pump water from wells. The U.S. Geological Survey’s (USGS) Groundwater Resources Program has found that the volume of groundwater stored in the earth is decreasing in many regions of the United States, and if this continues we could deplete our groundwater. We are running a groundwater deficit in many parts of our country, though we have adequate rainfall. LID can help by increasing water infiltration and reducing runoff.

In addition to the problems caused by stormwater and non point source runoff, many older cities (including many of the largest cities in the United States), have combined sewage and storm water systems which results in the storm water runoff overflowing the combined sewer system during storm events and diluted, but nonetheless raw sewage being released to rivers and estuaries. This is an ongoing problem in Baltimore and at Blue Planes in Washington DC as well as other cities throughout the nation. In the late 20th century, most cities that attempted to reduce sewer overflows did so by separating combined sewers, expanding treatment capacity, expanding storage within the sewer system, or by replacing broken or decaying pipes. San Francisco and many other cities have taken all of these steps, but still have much more that needs to be done. It is unfortunate that more of the stimulus dollars were not spent to repair expand and improve the waste water treatment facilities in our oldest cities instead of pursuing $54 billion in direct loans and loan guarantees to green energy companies. Repairs and improvements to our waste water treatment systems would have served our nation for several generations rather than been wasted on unproven technology or enriching favored entrepreneurs.

Managing rain water and snow melt is at the heart of LID. Rain water and storm water management under LID is landscape based and not particularly new. At the larger regional or watershed scale, green infrastructure is the interconnected network of preserved or restored natural lands and waters that provide essential environmental functions. Large-scale green infrastructure may include habitat corridors and water resource protection. At the community and neighborhood scale, green infrastructure incorporates planning and design approaches such as compact, mixed-use development, parking reduction strategies and urban forestry that reduces impervious surfaces and creates walkable, attractive communities.

At the site scale, green infrastructure is LID and mimics natural systems by utilizing permeable surfaces to absorb storm water back into the ground (infiltration), using trees and other natural vegetation to convert it to water vapor (evapotranspiration) and using rain barrels or cisterns to capture and reuse storm water. These natural processes manage storm water runoff in a way that maintains or restores the site’s natural hydrology, allowing groundwater to recharge. Site-level green infrastructure is LID, and can include rain gardens, porous pavements, green roofs, infiltration planters, trees and tree boxes and rainwater harvesting for non-potable uses such as toilet flushing and landscape irrigation. LID not only reduces the velocity and quantity of runoff protecting our streams, rivers, lakes and estuaries, it is essential to allow the recharge of groundwater.

The difficulty with LID is compliance and maintenance. Federal Clean Water Act requirements, such as the Combined Sewer Overflow (CSO) Control Policy and National Pollutant Discharge Elimination System (NPDES) permit program, do not allow for deviance from traditional control strategies. EPA guidance which encourages LID and green infrastructure to manage storm water is inconsistent with permit requirements under NPDES that call for more conventional methods of stormwater management.
NPDES regulations require development and implementation of a municipal separate storm sewer system (MS4) program to address post-construction runoff from newly developed and redeveloped areas. Investments in stormwater management and wastewater treatment plants are driven by compliance with regulations, which do not allow local policy makers to implement watershed-based or decentralized LID infrastructure solutions that may not yet have the data necessary to demonstrate performance and receive regulatory credit under a permit. Within the Chesapeake Bay Watershed the Chesapeake Bay Model provides credit under the Watershed Implementation Plans for LID retrofits, but not all practices are credited appropriately (both because of the amount of time needed for these practices to show long-term performance, as well as limitations in historic data collection). LID is by its nature a distributed design involving, rain gardens, porous pavements, green roofs, planters and rainwater harvesting require ongoing maintenance of the plants, replanting after severe winters or prolonged droughts, weeding, and clearing of porous pavements. There does not yet exist a method of ensuring that these features are maintained appropriately to continue functioning over time and that any repairs or replacements are done with LID in mind.

Low Impact Development and Oaks III Project

The Oaks III project was approved by the Prince William County Board of Supervisors after a public hearing on January 10th 2012. This proposal to rezone almost 18 acres of land adjacent to the Oaks II development and near the Town of Occoquan is an example of how Prince William County is attempting to continue to grow under the demands of the Total Maximum Daily Load (TMDL) mandated by the EPA. Prince William County finds itself along with a large portion of Virginia, Maryland, Washington DC and portions of several other states needing to reduce the amount of run off and better manage existing storm water to meet the goals of the Chesapeake Bay pollution diet, the TMDL mandated by the EPA.

Excessively high levels of nitrogen, phosphorus and sediment in the Chesapeake Bay cause algae blooms that consume oxygen and create “dead zones” where fish and shellfish cannot survive, block sunlight that is needed for underwater Bay grasses, and smother aquatic life on the bottom. The result is fish kills and murky water that threaten the fishing and shellfish industries and recreational use of the bay. The high levels of nitrogen, phosphorus and sediment enter the water from a variety of sources, including agricultural operations, urban and suburban runoff, wastewater treatment facilities, septic systems, air pollution, and minor contribution from natural processes. However, the largest share of nutrient and sediment pollution results from man: suburban development, cars and roadways, agricultural activities to feed man and human and animal waste.

The TMDL sets a total Chesapeake Bay watershed limit for the six states and Washington DC of 185.9 million pounds of nitrogen, 12.5 million pounds of phosphorus and 6.45 billion pounds of sediment per year which is a 25% reduction in nitrogen, 24% reduction in phosphorus and 20 % reduction in sediment from the current levels. The pollution limits are then partitioned to the various states and river basins based on the Chesapeake Bay computer modeling tools and monitoring data. The TMDL addresses only pollution from excess nitrogen, phosphorus and sediment and does not address toxic, carcinogenic or endocrine disruptors that may be present in the Watershed.

The Virginia Watershed Implementation Plans (WIP) Phase I and II lay out a series of pollution control measures called best management practices, BMPs that need to be put in place by 2025, with 60% of the BMPs completed by 2017. While it will take years after 2025 for the Bay and its tributaries to fully heal, EPA expects that once the required BMPs are in place there will be gradual and continued improvement in water quality as the BMPs reduce the nutrient and sediment run off and better control storm water so that the Chesapeake Bay ecosystem can heal itself.

About 37% of Prince William County is served by the HL Mooney Waste Water Treatment Plant which after its recent expansion and upgrade is state of the art in waste water treatment with monthly discharge averages are less than 0.1 for phosphorus, TSS 1 mg/l, BOD non- detect and nitrogen is currently 3 mg/l. Nonetheless, Prince William County needs to reduce the amount of nitrogen, phosphorus and sediment released to the Chesapeake Bay each year to meet the demands of the Virginia Watershed Implementation Plan because the cost to upgrade every waste water treatment plant and every municipal storm sewer system in the state was estimated at three times the cost of implementing best management practices throughout the state.

So, Prince William County finds itself needing to reduce existing runoff from the remaining agricultural operations within the county, urban runoff from towns, suburban runoff, septic systems, and air pollution (if possible) and still be a vibrant community. The Oaks III is the first example of the steps that Prince William County is taking to implement low impact development, LID, features with new growth and use the opportunity of new development to implement BMPs on older projects. LID is the latest catch phase in ecologically friendly site development and consists of five elements: preserving open space and minimizing land disturbance; protecting natural drainage ways, soils and sensitive areas; incorporating natural site elements like wetlands, stream corridors, and woodlands as site features; reducing the size of traditional infrastructure; and decentralize and manage storm water at its source.

The almost 18 acre parcel will be divided into four areas, the largest, 13.6 acres, will be a conservation area. Though public access to the area was not outlined in the proposal, this will serve to preserve open space and limit land disturbance on site. The reduced size of the development planned for the site will result in 8.5% of the site to be covered with impervious surfaces (roads, buildings, parking lots and sidewalks). The developer intends to use LID techniques to manage storm water and runoff on-site including methods to slow storm water flow rates. Instead designing the storm water management system so that it rapidly drains the site, low-impact development relies on design tools and control practices to preserve the natural hydrologic functions of the site. The specifics of the design will be addressed during site plan review in consultation with the developer’s engineer. In addition, the developer will use BMPs to restore 400 feet of the stream channel of the existing on-site intermittent stream. Then, the developer will be required to go back and improve the storm water management on the Oaks II development by installing a new stilling basin in the conservation area where the Oaks II storm water outfall is located. This is planned to slow the storm water flow during large storm events to allow water to infiltrate the soil. The Department of Watershed Management will approve the design to make sure that these BMPs improve the existing storm water management and generate “credit” under the TMDL.

Together the development of Oaks III should result in additional commercial space, additional housing and a reduction in storm water peak flow by using on-site infiltration, on-site bio-retention ponds, grass swales, rain water cisterns and French drains-all tools in the LID technique to mimic natural drainage through distributed control of storm water throughout the entire site. The challenging soils and slope at the Oaks III project should test the effectiveness of implementing these strategies.