Less Rain Means a Cleaner Bay

Rainfall has been below normal. In the Washington Metropolitan area Virginia, Maryland and the District of Columbia are dependent on the flows of the Potomac River and the Occoquan for their water supply. Potomac River basin has been abnormally dry this year with the eastern shore of Maryland in a moderate drought and river flows below normal. Although the recent rainfall has eased drought in some areas, not enough rain has fallen to raise watershed stream flow to normal levels. Temperatures have been abnormally high and there appears little chance for precipitation in the near term.  But for now, the Interstate Commission on the Potomac River Basin, ICPRB, reports that from a water supply perspective, there is sufficient flow in the Potomac River to meet both the Washington metropolitan area’s water needs and the environmental water flow needs without augmenting river flows by releasing water from the upstream reservoirs. So we can enjoy the clearer flows of the river with little worry or need to conserve water for now.

The ICPRB allocates and manages the water resources of the Potomac River through the management of the jointly owned Jennings Randolph and Little Seneca reservoirs, the Potomac River Low Flow Allocation Agreement and the Water Supply Coordination Agreement adopted in 1982 which designated the ICPRB as responsible for allocating water resources during times of low flow and assist in managing water withdrawals at other times. The ICPRB limits water withdrawals by the local water utilities coordinating Fairfax Water’s utilization of the Occoquan and Potomac and limiting total withdrawals from the Potomac if necessary. In the event that the Potomac River flow at Little Falls is below 700‐million gallons per day the ICPRB releases water from Jennings Randolph and Little Seneca reservoirs to make up the flow and ensure that the saline and freshwater balance necessary to maintain the oxygen levels for oysters, clams and crab populations is maintained. The reservoirs ensure in-stream flows to meet minimum aquatic habitat requirements and the drinking water needs of the region.  

The July 5th Water Supply Outlook from the ICPRB reports that both groundwater and stream flow remain adequate for the short term, but are below normal as rainfall has been below normal for much of the early spring and June. Jennings Randolph (the big reservoir) is full and we are not going to run out of water this year. The good news is that nitrogen and phosphorus contamination in the Chesapeake Bay could fall to the lowest levels since the droughts of a decade ago. The nitrogen and phosphorus contamination in the Bay is correlated with rainfall as seen below and we can enjoy this little preview of what a cleaner Bay might look like.

From the Chesapeake Bay Program 2012

Since the 1970’s large algae blooms have formed in both the Potomac and Upper Bay portions of the Chesapeake Bay watershed each summer. Larger than normal blooms occurred in the upper Chesapeake Bay and its tributaries during August and September 2000 and 2011. These blooms were probably the result of greater than normal amounts of freshwater and nutrients entering the Bay in those years, but there are still factors that need to be studied.  The dead zones form in summers when higher temperatures reduce the oxygen holding capacity of the water, the air is still and especially in years of heavy rains that carry excess nutrient pollution from cities and farms. The excess nutrient pollution combined with mild weather encourages the explosive growth of phytoplankton, which is a group of single-celled algae. While the phytoplankton produces oxygen during photosynthesis, when there is excessive growth of algae the light is chocked out and the algae die and fall below the interface between the warmer fresh water and fall into the colder sea water. The phytoplankton is decomposed by bacteria, which consumes the already depleted oxygen in the lower salt level, leaving dead oysters, clams, fish and crabs in their wake. Thus, the name- dead zone.

In a wedge estuary such as Chesapeake Bay the layers of fresh and salt water are not typically well mixed, there are still several sources of dissolved oxygen. The most important is the atmosphere. At sea level, air contains about 21% oxygen, while the Bay’s waters contain only a small fraction of a percent. This large difference between the amount of oxygen results in oxygen naturally dissolving into the water. This process is further enhanced by the wind, which mixes the surface of the water. Recent heavy wind storms may have increased oxygen levels in various water layers. ICPRB staff scientists will be working with Maryland and West Virginia natural resources scientists to survey algae blooms in the upper Potomac watershed. Researchers will visit numerous sites along the Potomac, its South Branch up to Moorefield, W.Va., the Cacapon River, and the lower Shenandoah River. The summer-long assessment will document the types and extent of algal blooms in this section of the watershed.

While the recent storm brought much damage, the powerful winds that took down trees also served to mix the waters of the Potomac. The waters of the Bay appear clearer than they have in recent years. While drought does improve nitrogen, phosphorus and sediment levels in the Bay in the short run, the cost of drought can be high (agricultural losses and water restrictions) and ultimately droughts end and the rains will come.  The Chesapeake Bay Foundation still judges the Bay to be “dangerously out of balance” despite progress made in the health of the Bay in the past 30 years and this year’s clear waters and healthy shad run. As the Washington Post Reported recently, the District’s 45 miles of Potomac watershed streams and rivers is so tainted with bacteria from the combined sewer overflows that the city prohibits swimming. The waters of the Potomac are the primary drinking water supply for the region they should be clean enough to be safe for swimming and recreation.  The Watershed Implementation Plans from the six states and Washington DC and the $2.6 billion sewage treatment plant upgrade for Washington DC under the Chesapeake Bay TMDL will further improve the waters of the Potomac and the Bay in the next decades. The Maryland, Virginia and the District estimates that it will cost more than $30 billion for them to meet the mandates of the Chesapeake Bay TMDL pollution diet over the next 13 years. Water is not free, it’s just we do not often see many of the costs associated with it. We need to see and understand all the cost of guaranteeing 24/7 access to clean abundant water.  

Nutrient Trading Markets, a Regulatory Pipe Dream

Under the Clean Water Act Virginia is required to meet the “waste load allocations” contained in the Chesapeake Bay TMDL. This can be accomplished though the Watershed Implementation Plans, WIP I and II, using a combination of agricultural BMPs, wastewater treatment plant upgrades, and improvements in stormwater management. If Virginia fails to meet these goals EPA will use the only regulatory sticks they have to force compliance. This could mean reducing Virginia’s federal funds for water quality or it might mean EPA directly permitting facilities in Virginia. This could mean more stringent requirements for wastewater treatment plants, MS4s, other stormwater permitting and confined feedlot operations.

So given the state of the federal budget (or lack there of) it seems a fairly certain that that Virginia will have to find a way not only to fund meeting the TMDL, but to get the local communities to embrace the WIPs, implementing the various strategies to reduce nutrient and sediment pollution. First, many existing wastewater treatment plants will have to be upgraded and any future population growth will require additional upgrades. These are major capital projects that will impact sewer fees within the communities served. We cannot meet the TMDL goal by only addressing wastewater treatment plants. Even if we could, there would still be a need for nutrient smoothing as expansions and technology improvements happened in spurts. Existing stormwater control systems will have to be upgraded in addition to having future development meet much more stringent current and future standards. Finally, agricultural nutrient management will have to be improved and widely implemented.

Much of the coastal area and northern Virginia is suburban. Curtailing future stormwater runoff by adopting low impact development, LID, techniques in new housing and in other development projects would, in many cases, not involve significant additional costs, but it will not achieve the goal of reducing the current nutrient and sediment pollution level as required under the TMDL. In addition, significant regulatory and business practices would have to change to implement LID. The changes would have to include zoning policies, current construction practices and building codes and any change is costly. The impervious surfaces associated with development like concrete sidewalks and asphalt roadways, and the buildings themselves create increased stormwater flow. Instead of soaking into the ground and recharging groundwater, rainwater runs across paved areas, collecting used motor oil, pesticides, fertilizers, and other pollutants. Under the TMDL mandate LID would not be enough to allow for any future construction in the Chesapeake Bay watershed.

Further nutrient reductions would be required to decrease the total nutrient load in the linear fashion dictated by the EPA. These nutrient pollution reductions could be achieved by requiring that new housing and other land development in the Chesapeake Bay watershed “offset” any new nutrient pollution load it generates by reducing the nutrient load elsewhere. These offsets could be provided directly or through the payment by developers of an “offset development fee.” The money from the fee could then be spent for upgrading stormwater control systems at older developments. This will have the effect of pushing up the cost of real estate in the Chesapeake Bay watershed by raising the cost of construction by the required fees. Existing housing and commercial building values would increase by the offset fees as well. Offset development fees are just one way to achieve this goal, but possibly the most painless. Another possible way to achieve the required reductions in nutrient and sediment pollution is to require all homeowners and building owners to implement improved stormwater control. The costs of these controls might not be reasonable in some cases, and lets face it, Virginia is struggling to get homeowners to appropriately maintain their alternative septic systems, adding stormwater control requirements does not seem likely to succeed.

Finally, it has been suggested that another way to achieve the TMDL goals is the regulators darling- the nutrient pollution trading model. Conceptually, pollution trading is appealing as a cost effective and flexible way to achieve and maintain water quality goals. However, I believe that it will prove impossible to create a pollution trading market place because of fatal flaws in the conceptual model. First, from a Bay-wide watershed perspective, the lowest-cost reduction efforts are not necessarily located within the watershed where a reduction is needed and the TMDL reductions do not appear to be tradeable on an intrastate basis. So the effective market for trading may be much too small to establish a market place. Uncertainty in reductions from agricultural sources cannot be entirely eliminated and must be implemented or maintained and funded every year, indefinitely, into the future. Monitoring and verification of BMPs are costly. http://www.dcr.virginia.gov/documents/lrNutrientTradingInTheStateOfVirginia.pdf

The regulators envision private entities that purchase large quantities of credits from nonpoint sources for the purpose of re-sale to potential buyers, such as regulated point sources. The regulators envision firms that are willing and able to accept and somehow manage the risks associated with trading fictional credits that have no other value, in an undeveloped and miniscule sized market place with an irregular demand based on economic and population growth and regulatory mandated decreases in the TMDL. In addition, the time lag inherent in BMP installation and verification will magnify the market instability and inefficiency by lagging market signaling.

The regulatory vision of a vibrant nutrient market cannot be achieved. In an economic sense, the regulations create an endowment- a regulatory endowed asset. New generation of nutrient pollution and sediment are prohibited while old activities are allowed (but must decrease over time). Unfortunately, unlike a really good asset, you can not value it, sell it or borrow against it and these are all requirements for property exchange. You cannot create a market without property rights that can be owned and sold. In addition, since the allowed activities and endowed asset are created by regulations they can vanish at regulatory whim.

There is no true economic value of a BMP (regulatory compliance not withstanding) so that installation cannot be financed and this would have to be a cash investment market that installs and maintains BMPs to have credits ready on demand. There are markets that function without credit, but the returns are venture capital returns (or illegal drug returns). In addition, BMPs do not pay “rent” and unlike bonds they cannot be warehoused, instead they are often seasonal and require expenditures and maintenance to continue to be viable. A series of nutrient markets can not succeed within the Chesapeake Bay watershed. The Commonwealth would be better served by regulators and local planning boards working together to effectively price and sell offsets to developers and wastewater treatment plants then ensure that they are installed and maintained if necessary.

Phosphorus in the Chesapeake Bay

Phosphorus is essential for plant growth, but soils in Virginia are naturally low in phosphorus. Virginia soils require supplemental phosphorus to maximize crop yields and so are a necessary agricultural fertilizer. Phosphorus enters to Chesapeake Bay watershed from the actions of man. Farming and agricultural activities are often seen as the only source of phosphorus, but that is not true. Phosphorus is a naturally occurring element that is naturally found in rock, soil, water and all living organisms. Of the estimated 17 million pounds of phosphorus entering the watershed, it was estimated in 2009 that about 8.3 million pound of phosphorus was from agriculture and 6.5 million pounds was from waste water treatment plants and urban runoff from predominately pervious surfaces (lawns). The growing suburban/urban population is a serious contributor to contamination. However, concentrated poultry feed operations are significant sources of excess phosphorus.

To give you some perspective on the quantities of phosphorus generated in sewage, according to the Delaware Department of Natural Resources and Environmental Control, the typical household generates 1-2 pounds of phosphorus per year and there are approximately 4.5 million households in the Chesapeake Bay watershed, representing 4.5-9 million pounds of potential phosphorus contamination (without the use of phosphorus removing technology at waste water treatment plants). According to a Maryland state study, each chicken generates approximately 0.35 pounds of phosphorus per year. Animal guano is a much bigger source of phosphorus than human waste, but the growing volume of households can create a problem that grows over the years.

The phosphate rock in its commercially available form is called apatite which is merely calcium phosphate. Other deposits may be from fossilized bone (animal or human) or guano (poultry waste). When plant materials and waste products decay through bacterial action, the phosphate is released and returned to the environment for reuse. Weathering and erosion of rocks and bones gradually releases phosphorus as phosphate ions which are soluble in water. A large percentage of the phosphate in water is precipitated from the water as iron phosphate which is insoluble. If the phosphate is in shallow sediments (wetlands), it may be readily recycled back into the water for further reuse. In deeper sediments in water, it is available for use only as part of a general uplifting of rock formations.

Most of the phosphate Chesapeake Bay watershed enters the water through the water run-off and release from waste treatment plants. Over application of phosphorus is caused by the use of manure from the concentrated poultry feed operations. Poultry typically has nearly equal concentrations of phosphorus and nitrogen, though crops typically require 2.4-4.5 times the nitrogen as phosphorus. Pig manure has slightly more nitrogen than phosphorus. Cow manure has typically twice the nitrogen as phosphorus and is much less of a problem. Historically, manure has been added to obtain the correct nitrogen content not the lower phosphorus needs. The excess phosphorus is released through leaching, runoff and erosion.

As for waste treatment plans without an expensive tertiary treatment, the phosphate in sewage is not removed during treatment. So what happens in the release areas from waste water treatment plants is that the phosphate sediment (iron phosphate) builds up over time. Lower the concentration in the waste stream and phosphorus is released from the sediment. As removal technology has improved for nitrates and phosphorus, waste treatment plants have had to exercise careful balancing act to control the algae blooms. I can find no studies of impact from release from single family septic systems and this may be due to the low concentration and plant uptake and mineralization.

Phosphorus can be found dissolved in the soil solutions in very low amounts or associated with soil minerals or organic materials. The relative amounts of each form of phosphorus vary greatly among soils, with the total amount of phosphorus in a clayey-textured soil being up to ten times greater than in a sandy soil. (University of Arkansas). Organic phosphorus in soils is made up of a large number of compounds, with the majority being of microbial origin. Organic phosphorus is held very tightly and is generally not available for plant uptake until the organic materials are decomposed and the phosphorus released via the mineralization process. Mineralization is carried out by microbes, and the rate of phosphorus release is affected by factors such as soil moisture, composition of the organic material, oxygen concentration and pH.

The reverse process, immobilization, refers to the tie-up of plant-available phosphorus by soil minerals and microbes that use phosphorus for their own nutritional needs. Microbes may compete with plants for phosphorus, if the decomposing organic materials are high in carbon and low in nitrogen and phosphorus. Mineralization and immobilization occur simultaneously in soil. If the phosphorus content of the organic material is high enough to fulfill the requirements of the microbial population, then mineralization will be the dominant process.

Most of the phosphorus added to soil as fertilizer and manure is rapidly bound by the soil minerals to the inorganic form and is not subject to rapid release. Thus, soil solution phosphorus concentrations typically remain very low, the concentration of inorganic phosphorus (orthophosphates) in the soil solution at any given time is very small, amounting to less than 1 lb/Acre. Phosphorus in the inorganic form occurs mostly as aluminum, iron or calcium compounds. This series of reactions is commonly referred to as sorption or fixation. Iron and aluminum compounds will fix (tie-up) phosphorus under acidic conditions (soil pH <= 7), phosphorus is preferentially fixed by calcium and magnesium compounds. Phosphorus availability to plants in most soils is greatest when soil pH is in the range of 6 to 7. Hard water is particularly high in calcium compounds, iron and magnesium which allows the mineralization and why septic systems may be able to handle the limited amount of phosphorus released by the typical human household each year.

Tough Choices Ahead for Virginia

The Chesapeake Bay and its tidal waters are impaired by amongst other things the release of excess nitrogen, phosphorus and sediment. These pollutants are released from waste water treatment plants, from agricultural operations, urban and suburban runoff, wastewater facilities, air pollution and other sources, including septic systems that enter the tributaries and Chesapeake Bay. These pollutants cause algae blooms that consume oxygen and create dead zones where fish and shellfish cannot survive, block sunlight that is needed for underwater grasses, and smother aquatic life on the bottom. The US EPA has taken control of the situation and has developed a new federally mandated TMDL to restore the Chesapeake. The total maximum daily limit, TMDL, allocates a pollution budget among the states which will decrease over time.

The plan to meet the federally mandated TMDL is called a Watershed Implementation Plan, WIP. The six Chesapeake Bay states and the District of Columbia were required to develop WIPs to meet the federally mandated TMDLs. The EPA found Virginia’s WIP to have serious deficiencies. It did not meet allocations for nitrogen (6 percent over the limit) and phosphorus (7 percent over the limit), but did meet allocations for sediment (12 percent under the limit). In addition, the EPA found that the Virginia WIP relied on pollution trading programs but had no commitment to adopt new regulations relying instead on market forces. The EPA deemed the WIP to be vague and contain limited enforceability and accountability for filling the gaps identified by the EPA. The federal government will require Virginia to reduce their nitrogen release by an addition 12 million pounds per year, and their phosphorus release by 1.7 million pounds per year beyond those identified in the WIP. EPA has made it clear they will enforce reductions in the areas they can control under federal law to meet the TMDL. The EPA can only mandate reductions in waste streams from waste water treatment plants, CAFOs (concentrated animal feed operations), municipal separate storm sewage systems, MS4s and wastewater treatment plants.

To ensure that Virginia meets the TMDL goals the EPA will squeeze the MS4s, CAFOs and waste water treatment plants possibly beyond the economically feasible limit to get what they want. The EPA wants Virginia to develop a set of regulations for land use that will meet the TMDL. The Chesapeake Bay TMDL will force changes in how each of us lives, the costs for building new homes, hospitals, businesses and roads, the costs for repaving roads and redeveloping areas, the costs for building and operating a septic system, the cost of public water and sewage and taxes. That is the price of growing population density and a healthy and sustainable Chesapeake Bay. About half the land and 60% of the population of Virginia is within the Chesapeake Bay TMDL.

The first TMDL to be developed for Prince William County, Virginia (where I live) is for Cedar Run. The Cedar Run watershed is the land area that drains into Cedar Run and includes much of Nokesville. The nearly 87,000 acre watershed continues into Fauquier County. While EPA and environmental groups have emphasized the contribution of agriculture in the form of CAFOs and waste water treatment plants, the reality is that only a portion of Prince William County is serviced by the HL Mooney a WWTP and the Daly City units and the county only has two working dairy farms left. These days the horse farms greatly out number the beef cattle operations. Golf courses and suburban development are increasingly the sources of nutrient and sediment contamination in the watershed. The state and county is going to have to increase regulations on hobby horse farms, golf clubs and suburban developments. In order to meet the TMDL for the watershed changes will have to be made. No area will remain untouched by regulation.

For example along with the issue of backyard chickens, the county will have to readdress the zoning for horses. The keeping of a single horse produces approximately 45 pounds of manure per day, and depending on the type and amount you use, bedding can add another 20 +/- pounds of waste a day. If the horse was kept turned out year round (in our area that would require approximately 3-4 acres of open field per horse) then the horse would not be using bedding, which accounts for an addition 50% of the waste and the open acreage could serve as a solution to what to do with the manure. That single horse produces approximately eight tons of manure each year that would be "spread" by the horse at a rate of about two ton per acre per year. Spreading manure at this rate probably will not overload the plants or cause water quality problems through runoff. However, if the property lacks adequate field to keep the horses turned out, then the waste from the sacrifice area and paddocks needs to be managed to prevent excessive nutrient runoff and contamination of ground water. One of the things that will have to be addressed in future regulations is the open acreage requirements for horses.

Septic systems are another area that will have to be reexamined. Dutchess County New York did a study to monitor the nitrate concentrations associated with septic systems. They chose to use nitrate concentrations at half the drinking water level as a proxy for adequate dilution and natural attenuation of all contaminants. Historically, little thought was given to the dilution for wastewater components like nitrate and phosphorus in developing septic regulations. The NY Department of Health separation distances were assumed (and these are almost identical to the Virginia setbacks), but the overall regional density of septic systems was examined to ensure that groundwater and surface resources would not be overwhelmed by the total load of contaminants. The density recommendations were developed based on the nitrate concentrations. Nitrate was used as a proxy because all humans produce nitrate, it does not easily break down and there is a drinking water standard. The study found that overall average density of on-site waste disposal should not exceed one unit per 2-3 acres for an average size household to ensure water quality. In many neighborhoods septic density is much greater than one unit per 2-3 acres. In the WIP Virginia is beginning to address the possibility of requiring nitrate removal technology in new and repaired septic systems.

The county is currently considering a proposal to allow backyard chickens in residential areas. According to the Delaware Department of Natural Resources and Environmental Control, the typical household generates 10-15 pounds of nitrogen per year and 1-2 pounds of phosphorus per year. According to a Maryland state study, each chicken generates approximately 0.41 lbs of Nitrogen per year and around 0.35 pounds of phosphorus per year. Thus, each household with 10 chickens would generate 4.1 pounds of nitrogen and 3.5 pounds of phosphorus per year. This is a significant increase in the nutrient load of a typical house hold, a more than three fold increase in phosphorus load and an increase of nitrogen load by more than 30%. This additional waste is delivered in an uncontrolled manner to the surface. The poor location of a chicken coop could potentially impact ground water and well heads both on and off site and subject to runoff. Before Prince William allows additional nutrient loads they need to address reducing the current source of excess nutrient pollution.