The Coastal Plain Aquifer

 

The Northern Atlantic Coastal Plain aquifer system consists of six regional aquifers and extends from Raritan Bay, N.J. to the North Carolina-South Carolina State line. The crystalline rocks of the Piedmont Physiographic Province at the Fall Line mark the western limit of the aquifer. The eastern limit of the aquifer system is, for all practical purposes, the shoreline. The northern part of the Atlantic Coastal Plain is underlain by a wedge-shaped mass of semi-consolidated to unconsolidated sediments that thickens toward the ocean and is topped by a layer of crystalline rock.

The thickness of the sediments vary. At the New Jersey coastline they are about 4,000 feet, but the sediments reach as much as 8,000 feet along the coast of Maryland and 10,000 feet along the coast of North Carolina. The sediments consist of lenses and layers of clay, silt, and sand, with minor amounts of lignite, gravel, and limestone. The sand, gravel, and limestone make up the water bearing aquifers; some are traceable over long distances, whereas others are only local.

The aquifers are separated by confining units of clay, silt,and silty or clayey sand. Although water moves more readily through the aquifers than through the confining units, water does leak very slowly through the confining units, especially where they are thin or where they contain sand; the aquifers, therefore, are hydraulically interconnected to some degree.

A series of clay and silt confining layers separate the regional aquifers that are used for water supply (Masterson and others, 2015). Recharge enters the aquifer mostly from the outcrop areas in the landward part of the aquifer system, but some limited recharge comes from downward leakage through confining units.

The surficial aquifer is the uppermost aquifer in the aquifer system.  This aquifer consists of unconsolidated, locally gravelly sand, mostly of Quaternary age. Although a thin blanket of unconsolidated sediments makes up the uppermost Coastal Plain beds over wide areas, these sediments generally yield small volumes of water to rural and domestic wells. Water in the surficial aquifer is especially susceptible to contamination by human activities and saltwater intrusion. 

The Chesapeake aquifer underlies the surficial aquifer in most places, but the two aquifers are separated by a clayey confining unit that significantly slows the downward movement of groundwater, though does not prevent it. The Chesapeake aquifer consists mostly of sand beds of Miocene age.

The Piney Point-Castle Hayne aquifers and the Potomac-Magothy aquifers (which include Mago[1]thy, Potomac-Patapsco, and Potomac-Patuxent aquifers) are aquifers in the Northern Atlantic Coastal Plain aquifer system that are the primary sources of groundwater for public supply (Masterson and others, 2015). The Potomac aquifer in Virginia comprises part of the regional Potomac aquifer system, which also includes the Potomac-Patapsco aquifer and Potomac-Patuxent aquifer in Maryland, Delaware and New Jersey.

The Potomac aquifer is a confined aquifer that once formed artesian wells prior to being de-pressurized. The Potomac aquifer is several thousand feet thick for much of the Coastal Plain and contains hundreds of trillions of gallons of pressurized water. Unfortunately, what once seemed like a vast never-ending resource is being overused. In Virginia approximately 155million gallons of groundwater is pumped from the Potomac aquifer each and everyday.

The first hint of a problem was a drastic reduction the pressure of the confined water. Water no longer rose to the surface without lift pumps. Then the groundwater level began to fall. Deeper wells were needed to access water. This was followed by aquifer compaction – and now, land subsidence, saltwater intrusion and increased vulnerability to sea level rise.

This groundwater provides much of the drinking water in the Hampton Roads area. There is only Beaverdam Lake reservoir on the Coastal Plain of the Middle Peninsula that supplies drinking water, and no drinking water reservoirs on the Northern Neck. North of the York River almost all of the public and private drinking water comes from groundwater.  The rate of groundwater withdrawal from the Potomac Aquifer is currently unsustainable.

Groundwater in the Coastal Plain region in eastern Virginia is being used up. This has been confirmed by measurements of groundwater levels, modeling of the aquifer system by the U.S. Geological Survey (USGS) and measurements of changes in gravity by the National Aeronautics Space Administration (NASA). Reducing water use in the region to a sustainable level for the Potomac Aquifer would be economically devastating and quite frankly, an impossible task. You can’t take away water without a fight. We are left with either adding reservoirs and surface water systems or utilizing the water storage capacity of the groundwater aquifer. Like many parts of the country and Northern Virginia, the Hampton Roads area has turned their sights on reusing wastewater to supplement the drinking water supply. Their plan is to utilize the existing storage in the groundwater system.  

For 40 years Los Angeles County has recycled the water from wastewater treatments plants. This water from both secondary and tertiary treated wastewater is discharged into spreading basins on the surface to recharge groundwater. Groundwater recharge can be done by surface spreading or direct injection wells. It has long been know that soil filtration improves water quality and soil column studies with secondary effluent from wastewater treatment has shown dissolved organic carbon removal of about half by percolation through 20 feet of various soil types. However, the 40 years experience has found trace contaminants from disinfection by products in the groundwater.

Recharging an aquifer has lower capital costs than dam and reservoir construction, but carries risks and challenges.. The first challenge is geologic. The predominant geology of this area of Virginia makes the usual methods of artificial recharge- spreading basins almost impossible. Without using injection wells, to deliver water  directly into an aquifer it would not be practical. Artificially recharged water must first move through the clay zone and the only effective method is to use a recharging well. This method has risks, big risks. We are potentially introducing trace contaminants, precursors of disinfection byproducts, trace Pharmaceuticals and personal care products and many other unknow contaminants  from our modern world into our groundwater aquifers. Before we use reclaimed wastewater to recharge the groundwater aquifer to augment supply, we need to fully understand what contaminants (and emerging contaminants) survive treatment and are carried in the wastewater to the aquifer.

Enter the Sustainable Water Initiative for Tomorrow (SWIFT) project. It proposes to replenish the Potomac aquifer, eastern Virginia’s primary groundwater supply, with purified water. This purified water would be treated to be compatible with the existing water in the aquifer to ensure seamless integration into the system and introduced by recharge wells drilled at seven of the 13 Hampton Roads service District wastewater treatment plant sites. Recharge wells store water for future use by placing it deep underground into formations below the shallow soil layer.

This is a great concept, but the question remains is it possible to do safely in practice in Virginia? Currently, wastewater (sewage) travels through multiple levels of treatment at Hampton Roads Service District, HRSD’s, 13 wastewater treatment plants to ensure it meets regulatory discharge levels of particular contaminants that are measured and are protective of aquatic life and public health. With the SWIFT project, the treated wastewater will undergo additional treatment procedures in the Advanced Water Treatment Process to treat it even further in order to meet stringent drinking water standards. Right now, at the research center in Suffolk, Virginia a million gallons of day of treated wastewater is being further treated to meet the higher drinking water standards and pH and oxygen levels of the aquifer and is injected at low pressure to a well with open slotting between 500 and 1,400 feet below grade into the aquifer.

The groundwater aquifer serves to dilute the trace contaminants that survive the treatment plant, but we need to be honest and informed about what we are putting into or leaving in what is ultimately our drinking water supply. The water of the Potomac Aquifer has been protected for a millennium from man’s arrogance and lack of knowledge. Now we are injecting what we believe to be clean water directly into this water body. With plans to inject a million gallons of reclaimed water a day.

Maybe we should pump this water directly into the drinking water distribution system in Hampton Roads for a few decades to make sure there are no unexpected consequences before we pump a million gallons a day into the aquifer. The solution to pollution may not be dilution.

Karst Terrain and Groundwater

 

The carbonate-rock aquifers are the predominate aquifer in the Valley and Ridge (V&R) of Virginia; however, there are areas in the Piedmont and Blue Ridge (P&BR) that also contain carbonate-rock aquifers. In total the carbonate rock aquifers underlie an area with a population of more than 40 million people in 10 states.

Where carbonate rocks are exposed at land surface or are overlain by only a thin layer of confining material they are easily dissolved by rain. As rain falls it absorbs some carbon dioxide from the atmosphere and from organic matter in soil. As the water percolates through the soil the weak carbonic acid water dissolves limestone and dolomite by enlarging pores between grains of limestone or fractures in the rock.

Over time these openings become larger as more of the acidic water moves through the aquifer; eventually the openings may be tens of feet in diameter. The end result of dissolution of carbonate rocks is a type of topography called karst- characterized by caves and sinkholes.

Water-supply wells drilled into the carbonate aquifers in karst terrain are generally more productive than wells that tap other rock types. The carbonate aquifers, due to the presence of dissolution channels, are very vulnerable to contamination from the surface. The carbonate aquifers are particularly vulnerable where sinkholes allow for the relatively rapid movement of contaminants into and through the aquifer. In some areas, the carbonate aquifers are locally isolated from the surface by thick layers of clay or shale that can impede the downward movement of water and contaminants.

The carbonate aquifers of the Appalachian Valley and Ridge Province, formed during Appalachian mountain building, have highly variable karst aquifer characteristics. The Valley and Ridge, Piedmont, and Blue Ridge Aquifers demonstrate karst features such as caves, sinkholes, sinking streams, and conduits. They are still used as a major drinking water supply for individuals and public supply, but without careful management these wells can become problematic.

The combined Valley and Ridge and Piedmont and Blue Ridge aquifers of all type rank second in the Nation as a source of groundwater for private domestic supply, providing about 470 million gallons per day (Arnold and others, 2016). The Valley and Ridge and Piedmont and Blue Ridge aquifers are also an important source of public supply, providing about 195 million gallons per day. Land use overlying the Valley and Ridge and Piedmont and Blue Ridge aquifers is mostly undeveloped (49 %), agricultural (35 %), and urban land (17 %).

Valley and Ridge and Piedmont and Blue Ridge aquifers in Virginia and were evaluated by the USGS National Water-Quality Assessment Project, which began in2012 and continued through 2021. Below are excerpts from that evaluation. The above information was taken from the USGS Groundwater Atlas of the United States.

Samples were analyzed for 34 trace elements and major and minor ions. Contaminants from this group were detected at high concentrations in about 10 % of the study area (at the depth zone used for public supply) and at moderate concentrations in about 5 %. Arsenic, manganese, and strontium were the only trace elements detected at high concentrations.

Samples were analyzed for eight radioactive contaminants, of which four have human-health benchmarks. Radioactive constituents were detected at high levels in about 3 % of the study area, but were not detected at moderate levels. Gross alpha activity was the only constituent detected at high concentrations.

Samples were analyzed for five nutrients, of which two have human-health benchmarks. Common sources of nutrients include fertilizer applied to crops and landscaping, seepage from septic systems, and human and animal waste. Nutrients were detected at high concentrations in about 2 % of the study area and at moderate concentrations in about 11 %. Nitrate was the only nutrient detected at high concentrations.

Some constituents affect the aesthetic properties of water, such as taste, color, and odor, or can create nuisance problems, such as staining and scaling. Samples were analyzed for 11 constituents that have SMCLs. One or more of these were present at high concentrations or values relative to the SMCL in about 15 % of the study area and at moderate concentrations in about 18 %.

Total dissolved solids (TDS) concentration is a measure of the salinity of the groundwater, and all water naturally contains TDS as a result of the weathering and dissolution of minerals in rocks and sediments. The TDS concentrations can be high because of natural factors or as a result of human activities, such as applications to the land surface of road salt, fertilizers, or other chemicals in urban or agricultural areas. The TDS concentrations were high in about 5 % of the study area.

Iron and manganese were both present at high concentrations relative to the SMCL in about 5 % of the study area. Sulfate was present at high concentrations in about 2 % of the study area. In a few samples, the pH of groundwater was not in the SMCL range of 6.5–8.5. In those cases, the pH was less than 6.5; such waters are considered acidic and potentially corrosive.

VOCs were detected at moderate concentrations in 2 percent of the study area. The only VOC detected at moderate concentrations was chloroform.

Samples were analyzed for 227 pesticide compounds (pesticides and their breakdown products), of which 119 have human-health benchmarks. Pesticide compounds were not detected at high or moderate concentrations in the study area.

Virginia’s 2022 Energy Plan

Much of the below is extracted from the 2022 Virginia Energy Plan, the new event and the Press Release

Every four years Virginia Energy develops a comprehensive Virginia Energy Plan. On October 3, 2022 Virginia released its 2022 Energy Plan at an event held at the Delta Star facility in Lynchburg, Va. The theme of the plan was “all of the above.”

In 2020, the General Assembly passed the Virginia Clean Economy Act (VCEA), which mandated a goal of 100% zero-carbon energy generation by 2050 and prescribed increasingly strict Renewable Portfolio Standards (RPS) for Virginia's investor-owned electric utilities that are according to the Governor inflexible and unattainable.

Under the VCEA, Virginia is legally required to retire all baseload generation, except for the existing nuclear power plants, in favor of intermittent renewable generation. The VCEA will require additional solar panels enough to cover an area the size of Fairfax County. With the retirement of baseload generation which is dispatchable and always on-demand, utility scale storage is required to manage power demand when the sun isn’t shining and the wind isn’t blowing. Such battery storage is not yet cost effective.

On September 1, 2021, the SCC released their annual report on implementation of the Virginia Electric Utility Regulation Act, as required by statute. This report concluded VCEA will increase energy bills for Virginia ratepayers over $50 per month (almost $660 annually) between 2020 and 2030 with an expected rate increase of almost 6% annually over the next five years. The report concluded that electricity prices have risen and will rise substantially in Virginia.

In addition, in 2007, the General Assembly passed the Re[1]Regulation Act, allowing utilities to request to recover certain costs outside of their base rates through rate adjustment clauses (RACs) or riders. Since 2007, Virginia ratepayers have seen an increasing number of RACs accumulate on their monthly power bills. (The latest one increased my cost per kilowatt hour from 11.34 cents to 12.29 cents.)

In 2010, Virginia generated only 59% of all electricity used in Virginia the rest was purchased from other states in Virginia’s Regional Transmission Organization (RTO), PJM, which Virginia joined in 2005. Largely driven by the addition of natural gas generation facilities, Virginia grew in state electricity generation to 81.6% of consumption by 2020, allowing Virginia to supply lower cost power instead of importing power from other states.

According to the Governor there is simply no path for Virginia to successfully meet the requirements and timeline of the VCEA with even the existing demand for electricity. The energy needs of the Commonwealth, its businesses and its families are changing – and growing. Virginia is already the data center capital of the world and the industry is exploding along with the demand of 24 hours a day 7 days a week power needed to run them. Data centers require power all the time even when the wind does not blow or the sun does not shine, requiring greater and greater amounts of backup power supply and storage under the VCEA, capping the number of data centers allowed in the Commonwealth or a recasting of the VCEA timeline and goals.

In 2018 power demand for data centers was just over 1 gigawatt of power, by this past September that had reached 2.6 gigawatt of power (according to a Dominion Energy earning report in September 2022) and is projected to reach 5 gigawatts by 2025 with projects already under way. Data Centers will have an outsized impact on the electric grid in Virginia.

The changing energy ecosystem presents stark contrasts between the reliability of baseload generation needed for data centers on one hand and reduction of carbon emissions on the other. Between these dueling objectives is a debate over the relative cost to consumers of continuous baseload versus intermittent energy generation technologies. Baseload generators, like nuclear power stations and combined cycle natural gas, operate continuously and consistently over time to meet the peaks and troughs of power demand. Intermittent generators, such as solar and wind, can only operate when the sun shining or the wind blowing.

Reliability is predicated on sufficient baseload and the ability to meet peak demand with additional on-call or dispatchable generating power sources. Grid reliability is also impacted by the interactions between customers, utilities, the SCC and PJM (the regional grid operator) when it comes to planning for tomorrow’s energy needs. 

Today, the vast majority of electricity demand in Virginia is met by continuous and dispatchable generation sources, primarily natural gas, nuclear, and to a much lesser extent coal. Since 2010 Virginia reduced carbon dioxide emissions by 20%, sulfur oxides emissions by 91% and nitrogen oxides emissions by 58% primarily due to this shift from coal to lower-emission natural gas generation.

Renewable energy sources, such as solar and wind, provide electricity with a low variable cost, but on an intermittent basis. The output from these sources varies across seasons, weather systems and time of day, rendering them challenging to meet consistent energy demands – as experienced in recent years in California and Western Europe. VCEA requires the Commonwealth to retire its natural gas power plants by 2045 (Dominion) and 2050 (Appalachian Power). These facilities currently comprise 67% of the current baseload generation as well as 100% of the power plants that meet peak demand. This switch mandated by VCEA has not been successfully accomplished anywhere in the world, yet. We cannot mandate technological hope, we must instead push forward innovation.

During the foreseeable future, intermittent energy generation cannot meet all of our energy needs. Some of this capability could come from utility scale battery storage, but the reliability, cost, safety, and availability of raw materials to incorporate this technology is at odds with the timeline constraints of the current VCEA requirements. At this time, solar and wind generation are affordable in many locations, but battery storage systems required to turn these generation sources into dispatchable energy are cost prohibitive. At the same time the extraordinary growth in electricity demand by the exploding number of data centers under development in Virginia requires that the Commonwealth increase the effective base load.

To meet Virginians’ round-the-clock energy needs, full compliance with VCEA will require a reliance on other PJM states to produce the baseload generation capacity for the Commonwealth absent incorporation of currently unavailable grid storage, nuclear, or hydrogen technologies. As of December 2021, the total capacity mix of PJM includes significantly more coal at 27%, and lower amounts of natural gas (44%). 

In short, VCEA depends on Virginia outsourcing reliable baseload capacity to other states, many of which have a high percentage of coal and natural gas generation, and increasing Virginia’s dependence on electricity imports. As a result, supply and transmission of energy to Virginia homes and businesses has the potential to become less reliable than today.

“A growing Virginia must have reliable, affordable and clean energy for Virginia’s families and businesses. We need to shift to realistic and dynamic plans. The 2022 Energy Plan will meet the power demands of a growing economy and ensures Virginia has that reliable, affordable, clean and growing supply of power by embracing an all-of-the-above energy plan that includes natural gas, nuclear, renewables and the exploration of emerging sources to satisfy the growing needs of Commonwealth residents and businesses," said Governor Glenn Youngkin.

With that comment, the Governor proposed recasting the VCEA in the next legislative session and a “moonshot” goal of developing and building a small modular nuclear reactor in southwest Virginia.

Should there be Fracking in Virginia?

Fracking for natural gas already exists in Virginia.  It is very controversial and proponents and opponents are very emotional in the views. Though it is an old method of enhancing yield from a well, the recent advances in fracking and horizontal drilling for natural gas have resulted in the ability to economically access natural gas reserves in shale that the U.S. Geological Survey estimates are equivalent to twice the oil reserves of Saudi Arabia. This is energy security in a turbulent world. The annual production of methane in the United States had increased 30% from 2005 to about 30,171 billion cubic feet of gas a year.

Fracking is the current method of extracting unconventional oil and natural gas that is locked inside impermeable geological formations. Fracking is enabled by horizontal drilling and hydraulic fracturing (thus the name fracking). Fracking or hydraulic fracturing as it is more properly known involves the pressurized injection of fluids made up of mostly water and chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid opens or enlarges fractures in the rock. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing as the pumping pressure is released. The fracturing fluids (water and chemical additives) are partially recovered and returned to the surface or deep well injected for disposal. Natural gas or oil will flow from pores and fractures in the rock into the wells allowing for enhanced access to the methane or oil reserves.

The current debate over fracking centers on the economic benefits, energy security and potential environmental safety of the process. The greenhouse gas emissions from a coal-fired power plant can be reduced by about half and the mercury and sulfur emissions eliminated if the plant is replaced by a natural gas fired power plant. Opponents cite the potential negative health and environmental effects as reasons to ban the practice, while proponents tout its economic benefits, positive environmental impact of cleaner and lower carbon energy than coal, and energy security.

The environmental concerns include air pollution from the operation of heavy equipment, human health effects for workers and people living near well pads from chemical exposure, noise and dust, induced seismicity from the disposal of fracking fluids, and increased greenhouse gas emissions from poor well head control and continued use of hydrocarbons. However, the biggest health and environmental concerns remains the potential for drinking water contamination from fracturing fluids, natural formation waters, and stray gases. If fracking is done carefully and properly the safely extracted gas can reduce air pollution and even water use in electrical generation compared with coal and oil. However, the availability of vast quantities of natural gas is likely to slow the adoption of renewable energy sources and, if fracking is done poorly toxic chemicals from fracking fluid could be released into our water supplies and methane could be release to the air. (See Methane Regulations Coming Our Way and Virginia and EPA’s CO2 Cap)

Virginia has entered this debate, as untapped natural gas deposits are located within certain areas of the Commonwealth. The use of fracking has a long history in Virginia going back to the 1950s. A nitrogen-based foam has historically been used in the fracking process here. Natural gas from conventional reserves and coal bed methane has been produced in the Appalachian plan (in the southwestern area) of the Commonwealth where drilling and coal mining are significant portions of the local economy.

Currently, there are more than 7,700 natural gas wells in the Appalachian plane where drilling required fracking in the extraction process. To date, there have not been any reports of adverse effects on water quality from the fracking. The other environmental impact of an industrial process is not much different from coal mining, dust, constant truck traffic, noise. The expansion of coal bed methane production has been in rural Buchanan and Dickenson counties.

Other areas in Virginia are known to have methane reserves that could be accessed by fracking. The George Washington National Forest is the largest protected forest in the eastern United States at 1.1 million acres in the mountains of Virginia. Approximately half of the forest sits atop the Marcellus shale deposit. The U.S. Forest Service announced November 2014 that it will allow oil and gas drilling using hydraulic fracturing or any other legal and regulatory approved method, but only in the 16% of the forest with existing leases and privately owned oil and gas rights. This final plan reversed a 2011 Environmental Impact Assessment that recommended allowing drilling in 993,000 acres of 1.1-million-acre forest, but banned hydraulic fracking. The finalized plan will allow drilling on 10,000 acres in the forest now leased for energy development and on 167,000 acres whose mineral rights are privately owned. (The government never owned those rights. When the government acquired the land for the forest the owners retained the mineral rights.) Currently, there are no active gas wells in the forest or in surrounding private tracts.

The Taylorsville Basin is located north of Richmond and extends across the Virginia Coastal Plain in the tidewater region of the state. In a 2011 study by the U.S. Geological Survey estimated that the area could contain up to 1.06 trillion cubic feet of natural gas, not huge, but worthwhile economically. Shore Exploration, a Texas-based energy company, has reportedly leased the mineral rights from more than 80,000 acres in Virginia’s Northern Neck and Middle Peninsula spanning large sections of King George, Caroline, Westmoreland, Essex, and King and Queen Counties.

Currently, Virginia law prohibits drilling in the Chesapeake Bay waters and all of the tidal tributaries, but outlines the path for drilling to proceed in the non-prohibited areas of the tidewater region. Whether or not to allow drilling in areas that are not areas identified as part of the Chesapeake Bay waters and tidal tributaries is a regulatory decision, controlled by the Virginia Department of Mines, Minerals and Energy (DMME). Basically, in order to grant a permit, DMME must undertake an environmental impact assessment in consultation with the Virginia Department of Environmental Quality (DEQ). However, DMME is only obligated to consider the findings of the assessment, and ultimately maintains the full authority to issue the permit. Local communities that might be significantly impacted by truck traffic, there is no pipeline, no source of water for a hydraulic fracturing so thousands of truck loads would have to run on small rural roads.

On average, 3-5 million gallons of water are forced under high pressure into each well. Water must be transported to the fracking site in trucks that normally hold approximately 4,500 gallons of water. This means even with reusing the flowback from other wells hundreds of truckloads of water are required for each well. In addition to the mixing trucks that are necessary for adding the required fracking chemicals.

But the major concern over the water use stems from the “flowback” and “produced water” that resurfaces after the rock has been fractured or is produced from the well. It is typical for about a quarter of the water used to return to the surface over the life of the well. Only a small fraction, about 250,000 returns to the surface in the first weeks after the well is drilled. Still the flowback water must be safely collected, stored and treated. An appropriate regulatory structure for addressing flowback does not really exist in Virginia. Typically, large surface ponds are used to store this water, which is polluted with the various fracking chemicals, naturally occurring salts, and naturally occurring radioactive compounds. If the water meets specific standards after being tested, it can be applied to the local land for disposal. If it fails to meet those standards, it must be safely transported to an approved disposal facility. Unfortunately, there is no approved disposal facility.

There is significant concern that the contaminated water would be improperly stored for extended periods of time and could infiltrate into the ground and ultimately contaminate the Potomac Aquifer, which is the sole water supply for over half a million people in eastern Virginia. In addition, extracting natural gas reserves from the Taylorsville Basin would require drilling through the Potomac Aquifer. The real question is where should fracking be allowed?

Energy in Virginia

On October 14, 2014 Governor Terry McAuliffe released the 2014 Virginia Energy Plan that contained a snapshot of energy use in Virginia today using data from the Department of Energy’s Energy Information Administration (EIA). I thought I would share some of the highlights so you, too, can see who we are. Even as the energy mix for Virginia changes, it should not be forgotten that Virginia’s Appalachian Plain is coal country. Virginia accounted for 4.5% of U.S. coal production east of the Mississippi River in 2012, and the seaport at Norfolk is America's largest coal export facility that processed and shipped over 38% of U.S. coal exports in 2012. More than half of the energy used in Virginia is imported from outside the Commonwealth. Petroleum for transportation is a big part of that number, but we also import a significant portion of our electricity from out of state.

from EIA

Virginia’s net energy balance is negative, which also is the case for most other states. The big oil producing states and foreign countries provide most of the United Sates with petroleum products for transportation, heating and household use. The Commonwealth imported about 55% of total energy used in 2012, all of the 31.7% of energy used for transportation, in addition to the petroleum products used for heating, but also a significant portion of our electricity which in Virginia is used for lighting, heating, and cooling. Petroleum for all uses represented more than 34% of energy consumed in Virginia last year. Practically all the rest of the energy used, 66% was in the form of electricity from the various sources. The total energy used in Virginia in 2013 came from the following basic energy sources:

• 34% from petroleum (heating and household use and transportation)
• 20% from electricity generated outside Virginia
• 18% from natural gas
• 13% from nuclear-based electricity generation
• 9% from coal
• 6% from hydro, biomass, and other renewable sources 

The average Virginia residential electricity customer uses 14 megawatt hours per year of electricity that costs them an average of $1,584 per year. Virginia households use more electricity than the national average because electricity is used for space heating. Virginians use of electricity is similar to the use in neighboring states where electricity is also the most common heating fuel, according to EIA's Residential Energy Consumption Survey.

Virginia’s retail electric customers are served by three publically traded investor owned utilities (providing 84.1% of electricity used in the state), 13 electric cooperatives (providing 11.5% of electricity) and 16 municipal utilities (providing 4.4% of electricity). Virginia’s utilities own in-state and out-of-state generation facilities, and make contractual purchases of electricity from in-state and out-of-state producers, and spot purchases of electricity from the PJM wholesale market. Virginia’s utilities imported about 37% of the state’s 2012 electricity consumption from generation facilities outside of Virginia.

Electric utilities in Virginia are members of an interstate transmission operator known as PJM which provides independent operation of the wholesale bulk power market for our region. This system increases the reliability of the electric grid at the lowest cost by managing regional supply from lowest cost to highest cost to meet demand. This system has historically put coal powered electrical generation in the “baseload” (lowest cost and most plentiful) category, but that has been changing in response to U.S. Environmental Protection Agency (EPA) regulations targeting coal fired power plants in recent years ( Mercury and Air Toxics Standards, Cross-State Air Pollution Rule, and the Annual Fine Particle Health Standard). In addition, EPA’s recently proposed Clean Power Plan assigns CO2 targets for each state to be phased in between 2020 and 2030. To meet these CO2 limits Virginia will have to further reduce the use of coal generated electricity.

Electricity generated in Virginia in 2013 came from a variety of sources including:

• 35.7% from nuclear
• 29.7% from natural gas
• 28.7% came from coal
• 4.5% from renewables
• 1.2% from hydroelectric
• 0.2 % petroleum entirely imported in Virginia and represents about also is the case for most other states. 

The electricity generated in Virginia represents only about 64% of the electricity used in Virginia. In 2012 Virginia produced 70,739,235 megawatt hours of electricity, but used 109,876,345 megawatts. Nuclear generation provided approximately 40% of the electricity used in Virginia most from our two nuclear power plants the remainder from the PMJ purchases. The available nuclear generated power has not changed in decades, but there are projects that may be completed within the Commonwealth and PMJ in the future.

In 2002, coal provided approximately 52% of the electric power for Virginia but had fallen to 21% in 2013 due to the increasing regulations on coal fired power plants and the extended period of relatively inexpensive natural gas. As the economics and regulatory requirements for coal-fired power have changed, retirements, fuel switches and new natural gas capacity have been announced and are expected to continue under the EPA Clean Power Plan. Total generation in the Commonwealth has shifted from 82% of total megawatt hours produced from coal and nuclear in 2008 to 76% of total megawatt hours produced from natural gas and nuclear in 2012.

The energy generation mix in Virginia continues to change as natural gas becomes more abundant and available, less expensive and prices have enjoyed a period of stable low prices. However, oil and gas prices have historically been very volatile and this is likely to occur again. Saudi Arabia with the financial reserves to withstand a multiyear price war is currently attempting to maintain their world market share of petroleum products against Kurd and ISIS black market sales, Russian and Venezuelan cash flow needs and diminishing world demand as growth in the emerging markets slows even as new techniques increase recoverable gas and oil. Oil and gas prices will fall significantly in the short term even as winter demand is upon us. It will be interesting to see what the composition of the base load will be in the next 15 years, remember before the oil supply crisis in the 1970’s petroleum, not coal made up the lion’s share of our nation’s electricity base load.

in energy equivalent units

Tornado Risk

from NOAA Tornado Frequecy

Though tornadoes occur all over the Earth, not limited to any specific geographic location, some parts of the world are much more prone to tornadoes than others. Globally, the middle latitudes (that would be us), provide the most favorable environment for the creation of tornadoes because this is where cold, polar air meets warmer, subtropical air, generating precipitation along the air mass collisions. In addition, air in these mid-latitudes often flows at different speeds and directions at different heights conducive to creation of rotation within the storm.

Tornadoes have been documented in every state of the United States, and in terms of absolute count, the United States leads the world, with an average over 1,000 tornadoes (EF-0 to EF-5) recorded each year. A distant second is Canada, with around 100 per year. Interestingly, the places that receive the most frequent tornadoes are also fertile farmland area. This is due in part to the high number of convective rain storms in these areas. One of the main difficulties with tornado records is that a tornado, or evidence of a tornado must have been observed. If a tornado occurs in a place with few or no people, it is not likely to be documented. Much of what we know as tornado alley of the central plains was very sparsely populated until the 20th century, and so the historical record before 1950 may not be accurate.

Tornado intensity is measured by the Fujita Scale, F, (also known as the Fujita-Pearson Scale) and the Enhanced Fujita Scale, EF, that imperfectly links damage to wind speed, but is relatively easy to apply in practice without much additional expenditure of time or money. The scale is used to rate the intensity of a tornado by examining the damage caused by the tornado after it has passed over a man-made structures. Generally speaking the intensity of tornadoes ranges from F0 (or EF-0) to F5 (or EF-5).

In the United States, there are two regions with a disproportionately high frequency of tornadoes. Florida is one and "Tornado Alley" in the south-central U.S. is the other. Florida has numerous tornadoes simply due to the high frequency of almost daily thunderstorms and the southeast and Gulf Coast are not far behind. However, despite the violent nature of a tropical storm or hurricane, the tornadoes they create tend to be weaker than those produced by non-tropical thunderstorms.

Frequency of stronger tornadoes in the U.S.

So should I worry, should I consider installing a tornado shelter in my home (beyond the partially above ground basement that my house already has)? John Nelson of IDV Solutions put 62 years worth of tornado data from NOAA on a map. John plotted each tornado's path and used brightness for its level of intensity. IDV Solutions is a cool company that sell what it calls Visual Fusion software. Visual Fusion is data visualization software for building interpretive images from virtually any data source. These images are used to connect all data in a single view, enabling those to whom columns of numbers do not speak to interpret data in a visual, interactive way to improve understanding and insights. John’s visualization shows that tornadoes in general arrive from the southwest and travel to the northeast, but more importantly for me the brightness of the lines indicates the intensity of the storm and the storms that have occurred in the Piedmont of Virginia have not been intense tornadoes. However, his data visualization lacks a time parameter. Looking at the frequency graph of tornadoes from NOAA it appears that the frequency of intense storms has not increased since the peak in the 1970’s, but the overall frequency of all tornadoes surpassed the 1973 peak in 2011, but fell again in 2012. Of course 2013 could be a very big year for tornadoes. Nonetheless, it looks like for my home, building or installing a FEMA 320 certified storm shelter is not a top priority. I may get one someday if I ever have a large sum of extra money, but I may just reinforce a below ground section of my basement with a FEMA 320 safe room kit.

from John Nelson IDV solutions showing tornado intensity and direction

In storm shelters there are two options: a site-built shelter or a commercially manufactured shelter. A site-built shelter is one that is built into your house during construction- building a closet or bathroom to meet the necessary design standards developed by Texas Tech and adopted by FEMA. The FEMA 320 standard is not easily retrofitted into a standing house. There are also commercially manufactured shelters that can be purchased, they range from the old stand-alone Auntie Em style storm cellars, to ones that are designed to be installed in the floor of a garage or underneath and as part of the steps of a pre-manufactured home.

If you choose to purchase and install a tornado shelter, make sure the shelter you select has been approved, tested and certified by the National Storm Shelter Association to meet FEMA 320 standards. On the market there are above-ground, below-ground and partially below-ground models that have been tested and certified. For any shelter which is partially or completely above-ground, the walls must be resistant to debris impact. Make sure the shelter you select has been tested for debris impact resistance by Texas Tech or if it is a below ground shelter the door has been tested and certified as resistant to debris impact. 

detail from John's map showing Tornado intensity in parts of NC, VA and  MD

Finally, if a tornado watch has been called (and scrolls across your TV or announced on the radio) it means that tornadoes are possible in the area and you should think about how you will protect yourself and your family this is your chance to get ready. Hopefully, you already have and emergency plan, and storm supplies (like a radio, flashlight and water) and are ready to act quickly if a tornado forms in your area. A tornado warning means a tornado has been sighted by weather radar and you should act immediately to seek shelter. If you are in a house, go to the lowest level such as a basement or storm cellar. If there is no basement, go to an interior room such as a closet, hallway or bathroom. Try to protect your head from flying debris or broken glass-blankets, bicycle helmets. If you are in a mobile home, you should leave immediately and seek shelter elsewhere. If you are outside and cannot get to shelter, crouch beside a strong structure or lie flat in a ditch or low-lying area and try to cover your head and neck. Get as far away from trees and cars as you can. A car is not safe in a tornado and parking a car under an overpass is not effective protection.

Sinkholes

from Sinkholes, West-Central Florida USGS

Sinkholes can vary from small shallow depressions in the earth to holes that are hundreds of feet deep and cover hundreds of acres. Some sinkholes even hold water and form natural ponds and lakes. Typically, sinkholes form so slowly that little change is seen in one's life- time, but they can form suddenly when a collapse occurs. Such a collapse can have a dramatic and devastating effect if it occurs in an urban or suburban setting as recently happened in Hillsborough County near Tampa, Florida when a sinkhole opened beneath a house swallowing a man and his bedroom. The body was never recovered and the house was demolished. Western central Florida has a long history of sinkholes and because of geology and groundwater pumping is  particularly susceptible to sinkholes. In the water well fields for St. Petersburg located in Hillsborough County and surrounding counties sinkholes have occurred in conjunction with development of each of the well fields as well a throughout the region. Sinkhole formation is highest during dry months of the year and during drought, but overall appear to be increasing in frequency according to the U.S. Geological Survey, USGS, though there might be some reporting bias to the data.   

A landscape that forms sinkholes, sinking streams, caves, and springs is called a karst landscape. A karst landscape most commonly develops on limestone, but can develop on several other types of rocks, such as dolostone (magnesium carbonate or the mineral dolomite), gypsum, and salt, which are types of evaporates rocks. Rain is naturally mildly acidic, and slowly over time the weakly acids rainwater dissolves these deposits creating fissures. The deposits are highly permeable, and surface water passes through them quickly to underlying aquifers, eating away at the limestone and evaporates bedrock. Overtime this creates the voids that become sinkholes. There are three general types of sinkholes: dissolution sinkholes—depressions in the limestone surface caused by the erosion of limestone by rain; cover-subsidence sinkholes—formed as overburden materials gradually fill below surface fissures formed by the infiltration of rain; and cover collapse sinkholes—which occur in limestone terrain with a thick overburden or mantle after the fissures forms large cavities and the cover materials collapse into the subsurface voids. This third type of sinkhole is what occurred last week near Tampa.

Hundreds of collapse sinkholes of various sizes occur throughout the country each year and start unnoticed when infiltrating water or groundwater flowing in the subsurface creates a void where soil is washed away. Eventually the void or hole grows large enough that the soil above it can no longer bridge it. The soil bridge then suddenly collapses into the void below and a sinkhole forms. Often this happens when the water level that has been exerting an upward pressure- helping to hold up the soil bridge falls. This process usually takes many years to occur in nature, but it can be aggravated by human activities. Any activity that increases the amount of water flowing into the subsurface can speed up this process. Parking lots, streets, altered drainage from construction, irrigation, leaking swimming pools and roof guttering are some things that can increase runoff; even severe weather can cause sinkholes.

from the Florida USGS office

The most damage from sinkholes tends to occur in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania thought large areas of the United States are underlain by evaporates rocks (salt, gypsum, and anhydrite) and carbonates (limestone and dolomite), the rock types that are most susceptible to being dissolved away by water. Even when evaporite rocks are buried at great depths, in so called Mantled Karst terrain sinkholes can form. These sinkholes are the most sudden when the mantle give way. The western central portion of Florida is an area of Mantled Karst terrain, but most of Florida is prone to sinkhole formation because it is underlain by thick carbonate deposits and is so rich in groundwater. Development and overuse of the groundwater resources for municipal, industrial and agricultural water supplies has resulted in falling groundwater levels that play a role in sinkhole formation as well as development.

According to Ann B. Tihansky of the U.S.G.S. in Tampa and author of Sinkholes, West-Central Florida,“Induced sinkholes are generally cover-collapse type sinkholes and tend to occur abruptly. They have been forming at increasing rates during the past several decades and pose potential hazards in developed and developing areas of west-central Florida. The increasing incidence of induced sinkholes is expected to continue as our demand for groundwater and land resources increases. Regional declines of ground-water levels increase sinkhole occurrence in sinkhole-prone regions.” The sinkhole prone regions of the country can be seen below.All of Florida is karst terraine, but as can be seen below karst terrain also covers much of the Valley and Ridge Province of Virginia in the western third of the state. Small karst areas occur in the Cumberland Plateau, Piedmont and even the Coastal Plain provinces.

From USGS

If you have questions or worries about sinkholes, settling or earth movement in your yard, Florida has an excellent question and answer web site. 

Uranium Mining in Virginia a Threat to Our Water Resources

Last week the winter session of the Virginia General Assembly was called to order. Scheduled to be decided this winter is whether or not to lift a 30-year-old moratorium on uranium mining within the state. Senator John Watkins has introduced a proposal to require the state to draft uranium-mining regulations, essentially ending the 30 year moratorium on Uranium mining in the Commonwealth. Senator Watkins, from Powhatan and Senator Richard Saslaw, from Fairfax will carry the legislation in the Senate, and Delegate Jackson Miller, from Manassas, will introduce similar legislation in the House of Delegates. Now is the time to make your voice heard.

In 1978 a particularly rich deposit of Uranium was discovered at Cole's Hill in Pittsylvania County in south central Virginia. This was followed by a flurry of exploration for uranium deposits in Virginia. In 1982 the Commonwealth placed a moratorium on uranium mining. In recent years, as the price of uranium reached $140 around 2007, and two families living in the vicinity of Cole's Hill formed a company called Virginia Uranium, Inc. to begin exploring the uranium deposit once again. Though the uranium spot price has fallen to around $40, that is still more than twice the historical price, and Virginia Uranium and their supporters have called for the Virginia legislature to lift the uranium mining moratorium for now just on Cole's Hill. As this was all percolating in state politics, in 2009 the Virginia Coal and Energy Commission requested that the National Research Council convene an independent committee of experts to review all the literature and develop a report to identify the scientific, environmental, human health and safety, and regulatory aspects of mining and processing Virginia’s uranium resources. In addition, Fairfax Water commissioned a white paper on uranium mining and ended up with the Fairfax County Water Authority opposing uranium mining in Virginia and supporting the continuation of the moratorium on uranium mining in the Commonwealth.  

After reviewing these reports and as a voting member of the Potomac Watershed Roundtable I voted with the majority to maintain the moratorium on uranium mining. The Virginia Association of Soil and Water Conservation Districts with which I am also affiliated (through my volunteer work at the PWSWCD) also supports maintaining the moratorium. The Virginia Municipal League, the Virginia Association of Counties, the Virginia Farm Bureau, the Fauquier Water Authority, and local governments from Halifax and Virginia Beach, oppose lifting the ban. Last week Lt. Gov. Bill Bolling, who serves as the tie-breaking vote in the Senate if the vote falls to party lines (Sen Watkins is a Republican and Senator Saslaw is a Democrat so that does not seem likely), announced that he supports maintaining the moratorium on uranium mining. Let me tell you why I do not want to see the moratorium lifted at this time.

From the Fairfax Water White Paper

Geological exploration has identified more than 55 locations within the Piedmont and Blue Ridge regions of Virginia where uranium is found.  Uranium occurs in the Lovingston rock formation at a fraction of a percent.  In order for a uranium occurrence to be considered a commercially exploitable source of uranium ore, it must be of sufficient size, be at least 0.1% uranium to the other rock components in the deposit and be able to be mined and processed with current technology. So far only the uranium deposits at Cole Hill have been proven to meet these requirements. Even the “rich deposits” at Cole hill will produce 1,000 pounds of waste called tailing for every pound of uranium extracted. The waste, the mine tailings, is the problem.

There are several methods to mine and process uranium. The choice of mining method depends on the quality and quantity of the ore, the shape and depth of the ore deposit, the type of rock, and a wide range of site-specific environmental conditions. Because of the geology in the Commonwealth of Virginia, it is likely that only open pit or underground mining would be viable. While there are risks inherent in mining to worker the uranium miners would also face the additional risk of dust containing radiation.

After the millions of pounds of rock are removed from the ground by conventional mining methods, the uranium must be separated from the rock and minerals and other radioactive materials, impurities removed and yellowcake produced. Yellowcake is a concentrated form of uranium oxide made in a combination of crushing and/or grinding the rock and chemical processes to dissolve the uranium from the rest of the rock using acids or bases to leach the uranium from the rock dust. The yellowcake then needs to be separated, dried, and packaged. There is more than one type of processing and the choice depends on the nature of the uranium ore, the composition of the rock in the formation as well as environmental, safety, and economic factors. During uranium ore processing, several waste products are created, including tailings, leached residue and waste water. Tailings consist of everything that was in the ore except the extracted uranium. Tailings from uranium mining and processing operations contain radioactive materials remaining from the radioactive decay of uranium, such as thorium and radium as well as heavy metals also present in the rock. The real risks to Virginia are the risks of contamination to our water resources from the waste water and tailings. Uranium tailings are a source of radioactive contamination for thousands of years, and therefore must be controlled and stored carefully away from water which will erode and carry the radioactive materials into the ground and surface water.

Over the past few decades, improvements have been made to tailings management systems to isolate tailings from the environment. The long term effectiveness of these management systems has not been tested and uranium mining is typically carried out in arid environments. Virginia is subject to relatively frequent storms that produce intense rainfall. Natural events such as hurricanes, earthquakes, intense rainfall, or drought could lead to the release of contaminants into the waters of Virginia. It is questionable whether modern-engineered tailings containment could be expected to prevent erosion and surface and groundwater contamination for as long as 1,000 years. In Coles Hill alone the tailings waste will amount to over 118,888,000,000 pounds of pulverized rock with radioactive materials that can slowly leach into our groundwater through failure to prevent percolation of precipitation into the tailings containment or through accidents be released from impoundments to surface waters. Though Virginia’s rainfall averages 42 inches a year in past few years alone rainfall has varied from under 30 inches to a high of 82 inches of rain a year. Water is a great solvent and in Virginia it would seem impossible to keep such vast quantities of tailings permanently isolated from water.  

The only use for uranium is for weapons and nuclear powered reactors. The United States currently has 104 nuclear reactors in operation supplying about 20% of U.S. electricity, and in 2011 these reactors required 20,256 short tons of concentrated enriched uranium and this is not expected to change significantly in the future. In 2010, the United States imported 92 % of the uranium that it needed to fuel its nuclear power reactors. There appears to be adequate world supply for our limited number of nuclear power plants at this time. Uranium mining and processing represents unique risks to source water supplies from toxic and radioactive byproducts. The half-life of the uranium 238 and its isotopes is thousands of years. A containment failure will risk the groundwater and surface water supply of the Commonwealth, and for Cole's Hill will endanger the drinking water supply of Virginia Beach if there is a breach in containment. With current technology, the risk is too great.  The uranium will still be there when our knowledge of how to stabilize for hundreds of year the mine tailings increases to the point we can safely mine the uranium without endangering our water resources.

The formation the contains uranium in Virginia from Fairfax Water

Can the Grease to Keep Sewers Flowing

Starting this week you might begin to see utility trucks in Fairfax with signs to “Can the Grease” or “Stop the Grease.” Fairfax County Department of Public works is launching a new education and public awareness campaign to get you to stop pouring grease down the drain. When you flush it down the toilet, grind it in the garbage disposal, pour it down the drain in Fairfax county, most likely the wastewater and all that it carries with it travels through the 3,300 miles of sewer pipes within Fairfax county and ends up at one of six regional waste water treatment plants for the county: Noman C. Cole, Upper Occoquan Service Authority, Blue Plains, Alexandria Renew Enterprise, Arlington and Mooney in Prince William.  There are still a few areas in Fairfax that have septic systems covering the rest.

Fats, Oil and Grease, FOG as it is called in the waste industry comes primarily from food such as cooking oil, lard, shortening, meat fats, sauces, gravy, mayonnaise, butter, ice cream and soups. Sinks, dishwashers, cleaning wastewaters and food scraps put down disposals deliver the FOG to the sewer system, it can be liquid or solid when you put it down the drain, but turns viscous or solid as it cools in the miles of underground sewer pipes. As the FOG builds up, it restricts the flow in the pipe and can cause sewage to back up into homes and businesses, or premature failure of the sewer pipes, increased incidence of sinkholes. I was fortunate to be able to speak to Tom Russell, Director, Wastewater Collection Division Fairfax County, VA DPWES who manages the 140 employees and construction programs that keep the sewage flowing in Fairfax and has been with Wastewater Collection 16 years- about half his career as an Engineer and manager with Fairfax. Tom made sewer pipe maintenance sound so interesting that I took way too much of his time during an early morning interview.

FOG only really creates problems for the sewer lines if there is a disruption, like a tree root in a joint, or sag under a highway, a pumping station or something that might give the FOG a chance to catch on the pipe surface and cling to the walls of the sewer system. Since all pipes have some friction points, FOG is always a problem.  The FOG builds up one layer at a time making a smaller, narrower path for the water and waste to travel through, ultimately causing a backup or pipe to burst. Restaurants and fast food places produce much larger volumes of FOG than residences, so in Fairfax there is more aggressive monitoring of sewer pipes and manholes downstream of the malls and shopping centers. Time creates wear and tear on a pipe and without the aggressive maintenance in Fairfax there would be a much larger problem. In addition, restaurants and commercial kitchens are required to have grease traps between the sink and floor drains and the sewer connection and capture and recycle their grease, by having it hauled away. Nonetheless, this past year, there was a massive sewage back up along the side of I-66 across from Fair Oaks Mall. The 18 inch sewer main under I-66 will be replaced at a cost of $1,000,000 and completed in spring 2013, the Wastewater Collection Division has managed to prevent additional backups in the interim by getting the Health Department to address the compliance of the restaurants in the mall with the county regulations for grease and commercial kitchens. Better control of the grease in the mall food court prevented further backups in the damaged section of piping.

Maintaining the sewer pipes, clearing tree roots and keeping grease out of the system can prevent most sewer backups. Every day the Wastewater Collection Division does visual inspections of sewer lines and manholes using portable cameras put down manholes and a special closed circuit TV camera, CCTV, that the crews use. The manhole inspections are generally done in the neighborhoods and the larger sewer mains are checked using CCTV. The CCTV crews use their equipment to view 240 miles of sewer lines each year. Sewer lines range in size from 8-72 inch diameter, and the CCTV is used to monitor deterioration in the lines. There are 88,000 manholes in Fairfax and each manhole is viewed every 3-5 years depending on the age and material of the pipe and whether the pipe has already been rehabilitated. There are some county sewer lines that are inspected quarterly or even monthly if necessary.  Neighborhoods built after 1970’s contain PVC pipe are checked less frequently because PVC has been demonstrated to last longer, 50-100 years in other parts of the country.  

The sewer system in Fairfax County was built out over the last 70 years as the county developed. Every year Fairfax County spends $6,000,000 in a planned program to rehabilitate 125,000 feet of pipe within the sewer system. Rehabilitation of sewer pipes involves sliding a resin impregnated fiberglass liner into the pipe at a manhole and using steam to rapidly cure the lining and have it bond with the existing asbestos cement (transit) or cement pipes. After the lining is in place the connections of the lateral sewer pipes is cut out. The curing process leaves an indentation where the lateral joins the sewer main and the vendor the county hires to do the work cut out the “coupons” to open the laterals. Rehabilitating a sewer main takes just one day from early morning until late afternoon and then the residences or businesses can go back to normal use of water. The sewer system in Fairfax is fairly young, and the current program of planned replacement is a fraction of a percentage of the piping in the system.  Nonetheless, during the last fiscal year ended July 1, 2012 Fairfax had only 19 backups and manhole overflows in the Fairfax owned system and 2 pipe collapses attributable to maintenance issues.

You might be thinking that there were more sewage backups in Fairfax during the past year after all, how would the rooter companies (like Rotor-Rooter and Rescue Rooter) make a living if sewage did not backup with certain regularity. It is true, there are more sewage backups in Fairfax, but they do not belong to the county. In Fairfax County there is private ownership of the lateral sewer lines from the building until it ties into the county sewer main. The homeowner or building owner in Fairfax is responsible for the entire lateral line (even past the property line) and the connection. So, when sewage backs up into your house and you call the county they will dispatch a crew to open the manhole on your street and see if the sewer main in blocked. Chances are that the sewer main is clear and Fairfax will tell you the problem is yours. They do not count these backups in their statistics.

In the sections of the county that developed after World War II and until 1970 Orangeburg pipe was used for the sewer laterals. Orangeburg pipe was piping made by Orangeburg Manufacturing Company of  ground cellulose fibers bound together with a special water resistant adhesive, and then impregnated with liquefied coal tar- basically tar impregnated cardboard pipes. The joints were made with couplings of the tar impregnated cardboard. Over time, the pipe have proven susceptible to deformation and root intrusion two things when combined with a lot of grease cause sewer backups. This year could be a very bad year for sewer backups into homes because during droughts tree root seek the moisture in the sewer pipes and infiltrate the pipes especially the old Orangeburg pipes. Because these sewer laterals are essentially made of cardboard, using a spinning rotor to cut out the roots is likely to ultimately abrade away the pipe wall, but can be done several times before the pipe fails.

The grease from holiday cooking combined with the root infiltration from a dry summer are likely to result in a sewer backup in your home at the most inopportune time. The worst maintained pipes in Fairfax County are the laterals owned by the property owners. It is very expensive to replace your lateral sewer pipe because the homeowner not only has to trench their yard but also cut the roadway and curb to replace the pipe and connect a new lateral to the sewer main. After the pipe repair is complete the property owner is responsible for repairing the road and curb. In the late 1960’s PVC (polyvinyl chloride) pipe replaced Orangeburg pipe. There are a lot of sewer backups in Fairfax and there are other problems caused by the historic residential construction. The sanitary sewer system in Fairfax is an entirely separate system than the storm sewer system, but there are still storm related increases in flow due to the infiltration of stormwater into the sewers and flow of stormwater into drains and sump pumps illegally discharging in the sanitary sewer system. That excess flow can result in more than 150% of the average daily sewage flow.  When many of the homes in Fairfax were built, it was perfectly legal to connect basement drains to the sewer lateral and use the sewer system to transport the groundwater out of the neighborhood. Excess flow, root infiltration in the pipe and grease build up will ultimately cause the lateral to rupture. So, the County’s advice to “Can the Grease” is good advice for homeowners to save yourself some money and prevent sewer backups in your home.

I would like to thank Irene Haske and Tom Russell of Fairfax County Virginia Department of Public Works and Environmental Services for their time and help in researching this topic.    

Recycled Water in Fairfax, Virginia

All the water that ever was or will be on earth is here right now. More than 97% of the Earth’s water is within the in oceans. The remaining 2.8% is the water within the land masses, as groundwater, rivers, streams, lakes, and within the ice caps and glaciers (over 77% of fresh water is currently frozen). Only a fraction of water falls as rain each year to make the rivers flow, recharge lakes and groundwater. The water on earth never rests, it is constantly moving within the hydrologic cycle along various complex pathways and over a wide variety of time scales. Water moves quickly through some pathways -rain falling in summer may return to the atmosphere in a matter of hours or days by evaporation. Water may travel through other pathways for years, decades, centuries, or more. As the demand for water grows in our population centers, we are straining to meet the demand. Even in generally water rich areas there are limits to the availability of water and United States has slowly and quietly begun to address the availability of water by recycling the water.

Direct water recycling is reusing treated wastewater for beneficial purposes such as agricultural and landscape irrigation, industrial processes, toilet flushing, and replenishing a ground water basin (referred to as ground water recharge) and less commonly returning the water directly to reservoirs. Since 1978, the upper Occoquan Sewage Authority has been discharging recycled water into a stream above Occoquan Reservoir, one of the two potable water supply sources for Fairfax County, Virginia. Recycled water has been part of the Occoquan supply for 34 years and chances are if you are in Fairfax, parts of Prince William and Loudoun counties you have been regularly drinking recycled water. Noman M. Cole, Jr., a very forward thinking engineer, developed the Occoquan Watershed Policy in 1971. This policy was the acknowledgment that to continue supplying the region with drinking water, the Occoquan Reservoir would be used both for wastewater disposal and public water supply. To do this and protect public health the Occoquan Watershed Policy not only specified the type of waste treatment practices that would have to be adopted on a basin-wide scale, but it provided for an on-going program of water quality monitoring to measure the success (or failure) of the waste water treatment. This resulted in the construction of the Upper Occoquan Service Authority, UOSA, advanced wastewater treatment plant with tertiary treatment to replace the eleven small secondary treatment plants.

Wastewater treatment within the basin would have three stages of treatment, primary, secondary and tertiary or advanced treatment.  Primary Treatment consists of sedimentation and screening of large debris using screens and large settling tanks. Until 1960’s primary treatment was the only form of sewage treatment in most places. 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. Coagulation, filtration and disinfection take place in tertiary treatment. A coagulant is added, UOSA uses the high-lime process to reduce phosphorus to below 0.10 mg/L. This process also serves as a barrier to viruses, captures organics leaving secondary treatment, and precipitates heavy metals and other suspended particles. The UOSA permit requires total suspended solids, TSS, below 1 mg/L and chemical oxygen demand, COD, below 10 mg/L. To meet these stringent levels, multimedia filtration and activated carbon are used. Filtration removes organic matter, microorganisms and mineral compounds, and excess nutrients. The final barrier to pathogens is a chlorination and dechlorination process. UOSA uses sodium hypochlorite and sodium bisulfite. UOSA is has an expansion program underway to expand capacity to 54 million gallons a day, but according to 2012 Fairfax County disclosures, the plant currently operates closer to an average of just over 13 million gallons a day.

After disinfection the reclaimed water is released to the watershed cleaner than the rest of the river, according to Dr. Tom Gizzard ofthe Occoquan Watershed Laboratory. Financed by the wastewater treatment plants and Fairfax Water, the Occoquan Watershed Laboratory (OWL), was established by the Virginia Polytechnic Institute Department of Civil Engineering. The laboratory began its Fairfax operations in 1972, and has conducted comprehensive studies of receiving water quality, and effects of the waste water treatment effluents for 40 years. The current Director of the Laboratory is Dr. Tom Grizzard, professor of Civil Engineering at Virginia Polytechnic Institute and State University (Virginia Tech). When I spoke to Dr. Grizzard he pointed out that the water released into the Occoquan is “highly reclaimed wastewater” and not sewage effluent. There is a difference and Dr. Grizzard and the OWL staff make sure of it.

The Occoquan Watershed Policy is the oldest and largest reservoir augmentation program in the county and the second largest water recycling program in the country. The largest water recycling or reclamation program in the country and in the world belongs to the Orange County Water District and the Orange County Sanitation District jointly owned and developed the Groundwater Replenishment (GWR) system, the world’s largest water purification plant for groundwater recharge. The GWR System diverts secondary treated sewer water and purifies it through a series of tertiary treatments: microfiltration, reverse osmosis, ultraviolet disinfection and hydrogen peroxide. The cleaned water is returned to the groundwater basin to increase both the water supply and quality rather than discharging the treated sewer water to the ocean. The additional treatment of the wastewater is much cheaper that desalinization and makes the groundwater use sustainable-utilizing the groundwater basin as a reservoir.

In Fairfax County Virginia, water is withdrawn from the Potomac River and the Occoquan Reservoir and filtered, cleaned, disinfected and delivered as drinking water to the homes and businesses throughout the county (and in parts of Prince William and Loudoun Counties). Waste water from toilets, sinks, drains is collected by the sewer systems and six waste watertreatment plants that serve some portion of Fairfax County.  On average, Fairfax County uses 160 million gallons of drinking water per day from both the Corbalis plant and the Griffith plant drinking water plants. The combined total capacity of both plants is 345 million gallons/day. The drinking water systems are sized to deliver the peak demand on a 100 degree day when everyone is doing laundry and watering their lawns and everything else we do with water on hot summer days.  Most of that water (except what is used to irrigate landscaping) finds its way to a waste water treatment plant within the region. The wastewater processed in Fairfax County is fully treated and released into the river and streams of the Potomac watershed. (We will ignore the issues currently being addressed at Blue Plains.) To ensure the continuation of water supply during droughts, Fairfax is party to a low flow allocation agreement with the members of the Interstate Commission on the Potomac River Basin, ICPRB. In addition, Fairfax bought the rights to 14 billion gallons of water from the Jennings Randolph Reservoir. On an ongoing basis ICPRB coordinates Fairfax Water’s low flow water withdrawals between the Potomac and Occoquan. The Occoquan Reservoir contains 11 billion gallons that receives both natural river flow and about 13 million gallons of reclaimed water daily.

From Fairfax County

Noman M. Cole, Jr. Pollution Control Plant (named in honor of the engineer) is now engaged in a direct water recycling program, reusing treated wastewater for landscape irrigation and industrial processes. The Noman Cole plant releases its reclaimed water to Pohick Creek. Now the plant is engaged in the Water Reuse Project also known as the Purple Pipe Project, to directly reuse some of the water. (The pipes are colored purple to designate the water as non-potable.) The Purple Pipe project has completed the first phase of the project and is delivering 1.4-1.6 million gallons of fully treated waste water to the Covanta Fairfax, Inc. Resource Recovery Plant and Laurel Hill Golf Course via a recently constructed 5 mile purple pipeline, two large pumps, instrumentation and hypochloride disinfection. The Laurel Hill Golf Course will use the water to augment the on-site irrigation lake during the summer. Due to recent rains, the demand for water by the golf club is limited, but according to Michael McGrath the Director, Wastewater Treatment Division, Department of Public Works and Environmental Services, for Fairfax County, the Laurel Hills Golf Club can draw up to 27 million gallons a year of reclaimed water from the Noman Cole Plant. The Covanta Resource Recovery Plant is allowed to use up to 560 million gallons a year of Purple Pipe Water to irrigate the adjacent athletic fields and other purposes. The Noman Cole plant discharges and average of 45 million gallons a day to Pohick Creek, so this is just a small fraction of the daily flow.  The reclaimed water from Noman Cole makes up a significant flow to Pohick Creek so that there is a minimum environmental flow that should continue, but there is opportunity for growth in the Purple Pipe Project.

The project, which began in 2009, cost $16 million for the first phase (or about $600 per foot) with $6.5 million in funding coming from the federal stimulus funds through the American Recovery and Reinvestment Act, and the remainder was paid for by Fairfax county through a loan from the Virginia Department of Environmental Quality Clean Water Revolving Fund Loan Program. In the first partial year of operation the project will produce about 20,000 credits for Noman Cole Plant in the Virginia Nutrient Trading Program in addition to the reduced cost water. Nutrient trading programs provide wastewater treatment plants with flexible options for meeting and maintaining permitted nutrient load limits, but also could be used to meet the approximately 25% reduction in nutrients required under the federally mandated Chesapeake Bay TMDL. A nutrient credit is a reduction of one pound of nitrogen and worth (at the current time) $2. Though the first phase of the Purple Pipe Project will generate more credits next year, still at $2 per credit plus the price received for water and costs or $600 per foot there is virtually no way for Fairfax to utilize Purple Pipe to meet the TMDL goals or increase water supply without a significant rate increases for water and large volume users. If using reclaimed water is necessary for the region to maintain its quality of life, the cost of water will have to rise to cover the costs because we are already using all the cheap water.

The numbers break down like this: this project would have to produce cash flow of about $918,000 per year (rather than the projected under $200,000 for water and nutrient credits) to pay for the $16,000,000 cost at 3% interest (current AAA interest for 20 year bonds is above 3%) over 25 years.  (Though for this project the $6.5 million from the federal stimulus funds does not have to be repaid.) The Purple Pipe project is a very cool project, but at the current cost of water the capital costs are prohibitive. Or maybe, we've just had a glimpse of the marginal cost of water.