Sunday, October 30, 2022

Water Rates in the DMV Area

With the notable exception of Manassas Park,  water bills in our region have  been increasing. Manassas Park has finally surrendered its title of most expensive water in the region to the Town of Leesburg.

There is no true “cost” of water, the price charged for water, often does not reflect its value or true cost.  WSSC has been struggling to raise rates and increase revenue, even as water usage per person fall,  to pay for a decades long repair and restoration of their water and sewer distribution system. They are currently engaged in a 10 year program to replace over 2,000 miles of water pipe and similar amount or sewer pipes. WSSC needs to fund both ongoing operations and the billions of dollars in capital needed to rehabilitate, upgrade and replace water and wastewater infrastructure.

Recently, Fairfax Water announced its intention to raise their water rates next spring as they do almost every winter. There will be, as usual, a public hearing on Thursday, December 15, 2022, on the proposed rate increase held at Fairfax Water’s main office at 8570 Executive Park Avenue in Fairfax. This rate increase is part of their ongoing program to ensure that the water infrastructure in Fairfax County is maintained. The proposed rate increase will go into effect April 1. 2023. Visit for a complete list of rate and fee increases.

The need for infrastructure replacement is an issue that has caused significant service problems and rate increases in other parts of the Washington Metropolitan region. Fairfax Water Board of Directors have dedicated funding to infrastructure maintenance and replacement for many years, and has forecast future capital needs for replacing water mains in the system. The Town of Leesburg did not have a capital program in place. 

Every time they propose to raise water rates, Fairfax Water performs a comparison of the water costs throughout the Washington Metropolitan region. I have tracked this information (with exception of Pandemic years) above. This comparison is based on rates as of July 1, 2022 (and July 1, 2017, 2018, 2019) and on 18,000 gallons of residential water use for an established account over a three-month period. As you can see above even with this increase, Fairfax Water’s commodity rates will remain among the lowest in the Washington metropolitan region.  Fairfax Water sells water to Prince William Service Authority, American Water, Manassas Park and others.

Wednesday, October 26, 2022

Montclair Town Hall

 On Wednesday there was a Town Hall Meeting at the Montclair Library. Below is from my talk. 

If you live in the eastern portion of Prince William County you should care very much about the fate of the Rural Crescent because the Rural Crescent is about water, your water. The public water supply in eastern Prince William (blue and grey) comes from the Occoquan Reservoir. PWSA purchases 15 million gallons of water a day from Fairfax Water for you- it is all drawn from the Occoquan Reservoir.

The Rural Crescent allows rain water to flow gently over vegetation, soak into the earth, feed the aquifers that provide water to the private wells and the Evergreen water system. But groundwater also feeds the tributaries to Bull Run and the Occoquan River assuring a constant base flow to the rivers and streams that feed the Reservoir and control of stormwater.

from UOSA

Development will impair the recharge of the groundwater aquifer, but also increase sediment and salt that flows into the Occoquan Reservoir, reduce stream flow and deteriorate water quality while increasing demand for water to feed more homes, businesses and data centers.

Development increases impervious cover from roads, pavement and buildings does two things. It reduces the open area for rain and snow to seep into the ground and percolate into the groundwater and the impervious surfaces cause stormwater velocity to increase preventing water from having enough time to percolate into the earth, increasing storm flooding and preventing recharge of groundwater from occurring.


 According to the EPA groundwater recharge is reduced from 50% to about 15% and runoff increases from around 10% to 55%. To prevent flooding, storm damage and reduction in water resources that runoff needs to be captured and redirected. To make sure that this water is not lost, it will have to be stored for future use. 

When generally open rural area is developed stormwater runoff increases in quantity and velocity washing away stream banks, flooding roads and buildings, carrying fertilizers, oil, grease, and road salt to the Occoquan Reservoir. The salt level in the Occoquan Reservoir is rising almost to the critical point, Fairfax Water says it will cost $1-$2 billion to build desalination treatment at the water treatment plants. In addition, the Reservoir will have to dredged to restore the lost volume and potentially enlarged at great expense.


The salinity in the Occoquan Reservoir has been rising for a number of years and is reaching the critical level and will be made worse by development in the Rural Crescent and by data centers in particular. There are two ways that data center will increase the salt in the Occoquan:

Pavement. In winter all that pavement in parking lots around backup generators and roads will be sprayed with brine solution or salted and increase the salt content in the runoff.

Cooling. Cooling evaporates some of the water concentrating the salt that is already in the water. In addition to increase the efficiency and life of cooling equipment they soften it (which means they add brine, salt water). The minerals and salt build up in the cooling tower and are blown out. The cooling tower blow down contains high salt levels and is sent to the wastewater treatment plant which has no ability to remove salt.


The water in the Occoquan Reservoir comes from: Bull Run, the Occoquan River and the UOSA. A significant portion of the water flowing to the Occoquan Reservoir is from the Upper Occoquan Service Authority wastewater treatment plant. That water is getting saltier. It is believed that the other sources of sodium include the data centers effluent.


Haymarket data Center (AWS)

Data centers are also a potential source of diesel contamination to the watershed. The data centers need to operate 24/7 so they maintain a backup power system consisting of banks of giant generators. Data centers need immense amounts of power (2.6 gigawatts capacity and growing fast) they require about 40 - 2 Mw generators each to keep operating. Backup generators at a data center usually run on diesel; not one of the cleanest fuels. Banks of backup generators are lined up at each and every data center. To power these generators, diesel fuel needs to be stored onsite, so each site contains large fuel storage tanks with pipes and valves to feed each generator- all potential spots for leaks and spills.

Just to give you a look of how big these generators here are three next to a diesel fuel truck.

Our future and our children’s future is our water. We can’t allow it to be destroyed by paving roads and building data centers, warehouses and housing developments that will produce windfall profits for the landowners while leaving us with the bill of one to two billion dollars to remove the increasing salt level from the Occoquan Waters.



Sunday, October 23, 2022

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.

Wednesday, October 19, 2022

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.

Sunday, October 16, 2022

It's Raining a Little Bit More

 "Observed Changes in Daily Precipitation Intensity in theUnited States" is a new article published this month in the Geophysical Research Letters. This is a study by two Northwestern University researchers, Daniel Horton and Ryan Harp on how the intensity of rainfall has changed over time. The below is from the Northwester University press release:

“When people study how climate change has affected weather, they often look at extreme weather events like floods, heatwaves and droughts,” said Northwestern’s Daniel Horton, the study’s senior author. “For this particular study, we wanted to look at the non-extreme events, which are, by definition, much more common. What we found is pretty simple: When it rains now, it rains more.” 

Horton is an assistant professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences, where he also leads the Climate Change Research Group. Ryan Harp, an Ubben Postdoctoral Research Fellow at the Institute for Sustainability and Energy at Northwestern, is the paper’s first author.

To conduct the study, Harp and Horton compared two climatologically distinct time periods: 1951-1980 and 1991-2020. For each time period, they used historical precipitation data from the Global Historical Climatology Network, a publicly available database maintained by the National Oceanic and Atmospheric Administration. For the past 10 years I have been a rain gauge reader for the Community Collaborative Rain, Hail and Snow Network, the source of the data.

The researchers broke the observations into 17 distinct climate regions in the United States. These regions reflect differences in temperature, precipitation, vegetation and ecosystem dynamics. After analyzing data from two time periods across regions, Drs. Harp and Horton discovered that precipitation intensity (including rain and snow) had increased across much of the United States, particularly in the East, South and Midwest. Changes in the western United States were not detected.

In this study, Harp and Horton narrowed their focus to examine how much precipitation falls during each rain or snowfall event. For their next study, they plan to investigate if annual precipitation is becoming more variable and if precipitation events are becoming more or less frequent. Although this study does not attribute the changes in precipitation rates to climate change, Harp said the findings are consistent with human-caused global warming and climate model predictions.

“Warmer air holds more moisture,” he explained. “For every one degree Celsius the atmosphere warms, it holds 7% more water vapor. So, these observations are consistent with the predicted effects of human-caused global warming.”

If this is an indication of what we can expect in the future as the climate, weather and rainfall respond to the ever increasing CO2 equivalent emissions in the atmosphere, we need to take action to prevent increased damage from more intense rain. Increased precipitation intensities affect many sectors, including agriculture and infrastructure, as well as lead to increased risks of landslides and flooding. We need to design infrastructure that can accommodate more intense rainfall in our plans for future growth and development. We need infrastructure that is more resilient to changing weather patterns because they are changing.

“You don’t need an extreme weather event to produce flooding,” Horton said. “Sometimes you just need an intense rainstorm. And, if every time it rains, it rains a little bit more, then the risk of flooding goes up.”

Wednesday, October 12, 2022

The Piedmont and Blue Ridge Groundwater

About half of the nation’s population relies on groundwater for drinking water. As the nation’s population grows, the need for high-quality drinking-water supplies becomes ever more urgent. The USGS has identified 68 principal aquifers in the United States, these are regionally extensive aquifers that are used as sources of drinking water.

Groundwater pumped from these primary aquifers provides nearly 50% of the nation’s drinking water. Twenty of these principal aquifers account for about three quarters of the nation’s groundwater pumped for public supply. These aquifers also provide 85 % of the groundwater pumped for domestic (private) supply. Three of these principal aquifers are in Virginia and were evaluated by the USGS National Water-Quality Assessment Project, which began in2012 and continued through 2021. Below are excerpts from the evaluation of the Piedmont and Blue Ridge aquifers and information taken from the USGS Groundwater Atlas of the United States.

The Piedmont and Blue Ridge crystalline-rock aquifers underlie an area with a population of more than 25 million people in 11 states (map). The Piedmont and Blue Ridge crystalline-rock aquifers, together with the other rock types in the Piedmont and Blue Ridge regions, rank second in the Nation as a source of groundwater for private domestic supply, providing about 360 million gallons per day (Arnold and others, 2017a).

These aquifers are also an important source of public supply, and about 92 million gallons per day are pumped for that use. Land use overlying the Piedmont and Blue Ridge crystalline-rock aquifers is mostly undeveloped (71 %) and agricultural (19 %). The cities of Atlanta, Georgia, and Charlotte, North Carolina, overlie the aquifers, as well as suburbs of Richmond, Virginia; Washington, D.C.; Baltimore, Maryland; and Philadelphia, Pennsylvania.

The Piedmont and Blue Ridge Provinces are underlain by three principal types of bedrock aquifers. In order of decreasing area, these are crystalline-rock and undifferentiated sedimentary-rock aquifers, aquifers in early Mesozoic basins, and carbonate-rock aquifers. Unconsolidated aquifers that are part of the surficial aquifer system overlie the bedrock aquifers locally in Pennsylvania and northern New Jersey.

Crystalline-Rock and Undifferentiated Sedimentary-Rock Aquifers are the most widespread aquifers in the Piedmont and Blue Ridge Provinces. These aquifers extend over about 49,000 square miles, or about 86 % of the area, of these provinces. Most of the rocks that make up crystalline-rock and undifferentiated sedimentary-rock aquifers are crystalline metamorphic and igneous rocks of many types. The main types of crystalline rocks are coarse-grained gneisses and schists of various mineral composition; however, fine-grained rocks, such as phyllite and metamorphosed volcanic rocks, are common in places.

Unconsolidated material called regolith overlies the crystalline-rock and undifferentiated sedimentary-rock aquifers almost everywhere. Because the regolith material varies greatly in thickness, composition, and grain size, its hydraulic properties also vary greatly. However, the regolith is more permeable than the underlying bedrock. Water in the bedrock is stored in and moves through fractures, which form the only effective porosity in the bedrock.

Early Mesozoic rift basins are spread out in the Piedmont Province and occupy about 9 % of the combined area of the Blue Ridge and the Piedmont Provinces. Aquifers in early Mesozoic basins are primarily in three major basins-the Newark Basin in New Jersey and Pennsylvania is the largest basin and the one from which the most ground water is withdrawn; second largest is the Gettysburg Basin of Pennsylvania and Maryland; and third is the Culpeper Basin of Virginia.

The Culpeper Basin of northern Virginia and Maryland is an elongate, fault-bounded trough that trends north-northeast from the southern border of Madison County, Va., about 90 miles to Frederick County, Md. All the formations in the basin are part of the Culpeper Group. The lower part of the group consists of sandstone, siltstone, and conglomerate of Late Triassic age; the upper part consists of Lower Jurassic sedimentary rocks and interbedded basaltic lava flows.

The water in the Culpeper Basin is the least impacted by iron, manganese and sulfate in the region and of only moderate hardness. My home overlies a section of the Culpeper basin that runs through all but one small corner of northwestern Prince William County. I chose this area for the water. It requires no treatment.

Carbonate-Rock supports the largest aquifers in the Piedmont and Blue Ridge. Limestone, dolomite, and marble of Paleozoic and Precambrian age form carbonate-rock aquifers that extend over about 3 % of the Piedmont and the Blue Ridge Provinces. Although these carbonate rocks are of small extent, they are significant local sources of water. Carbonate-rock aquifers are in five areas of the Piedmont and the Blue Ridge Provinces. In addition to these areas, small, isolated elongate stringers of limestone and marble form minor aquifers locally, particularly in Virginia, and generally trend parallel to the Blue Ridge front.

Recharge is highly variable in the Blue Ridge and the Piedmont Provinces because it is determined by local precipitation and runoff, which are highly variable and are influenced by topographic relief, ground cover, compaction and the capacity of the land surface to accept infiltrating water. 

Most of the Piedmont and the Blue Ridge Provinces are covered by regolith. Compared to the Blue Ridge, the gentler topographic relief of the Piedmont and less precipitation make the Piedmont less subject to rapid denudation than the Blue Ridge and thus favor the accumulation of a thicker regolith. The combination of large areas of thin regolith and dense bedrock with minimal permeability in the Blue Ridge Province do not favor large amounts of ground-water recharge. These areas have a limited ability to provide water.

Almost all recharge is from precipitation that enters the aquifers through the porous regolith. Much of the recharge water moves laterally through the regolith and discharges to a nearby stream or depression during or shortly after a storm or precipitation event. Some of the water, however, moves downward through the regolith until it reaches the bedrock where it enters fractures in crystalline rocks and sandstones or solution openings in carbonate rocks.

The USGS Aquifer Studies were designed to evaluate groundwater used for public supply prior to any treatment. Groundwater quality was assessed by comparing contaminant concentrations to regulatory limits established for drinking water quality.  Trace elements and major and minor ions are naturally present in the minerals of rocks, soils and sediments, and in the water that comes into contact with those materials.

The USGS sampled 60 wells at depths that a used for public supply wells: 150-700 feet beneath grade. Samples were analyzed for 90 VOCs, of which 38 have human-health benchmarks. VOCs were detected at moderate concentrations in 5 percent of the study area but were not detected at high concentrations. Compounds detected at moderate concentrations were the disinfection byproduct chloroform and the solvent trichloroethylene (TCE).

Manganese was found to be present at high concentrations relative to the SMCL in about 15 % of the study wells. Iron was present at high concentrations relative to the SMCL in about 12 % of the wells.

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

In some areas, the pH of the groundwater was not in the SMCL range of 6.5 to 8.5. The pH did not meet the standard in 35 % of the study area, typically because it was less than 6.5, which is acidic and potentially corrosive.

The total dissolved solids (TDS) concentration is a usually considered a measure of the salinity of the groundwater, though all water naturally contains TDS as a result of the weathering and dissolution of minerals in rocks and sediments. Concentrations of TDS can be high because of natural factors or as a result of human activities such as applications of road salt, fertilizers, or other chemicals to the land surface in urban or agricultural areas. Concentrations of TDS were high in about 3 % of the study area. Chloride, fluoride, and sulfate—constituents that also contribute to TDS concentrations—were detected at moderate, but elevated concentrations.

Radioactivity is the release of energy or energetic particles during spontaneous decay of unstable atoms. Most of the radioactivity in groundwater comes from the decay of isotopes of uranium and thorium that are naturally present in minerals in aquifer materials. Samples were analyzed for eight radioactive constituents, of which four have human-health limits for drinking water. The USGS found radioactive constituents were present at high levels in about 30 % of the study area and at moderate levels in about 17 %. Radon (using the proposed alternative maximum contaminant level of 4,000 picocuries per liter) and gross-alpha activity were the only constituents that were present at high concentrations. Radium (combined concentration of Ra-226 and Ra-228 isotopes) was detected at moderate concentrations in 2% of the study area.

Nutrients are naturally present at low concentrations in groundwater; high and moderate concentrations (relative to human-health benchmarks) generally result from human activities. Samples were analyzed for five nutrients, of which two have human health benchmarks. Common sources of nutrients, aside from soils, include fertilizer applied to crops and landscaping, seepage from septic systems, and human and animal waste. No nutrients were detected at high concentrations in the study area. Nitrate was detected at moderate concentrations in about 3% of the study area.


Sunday, October 9, 2022

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.

Wednesday, October 5, 2022

Time to Replace my Smoke Alarms

from Universal Security Instruments website

 It is recommended that smoke alarms should be replaced after about 10 years. There have been very few studies to determine the actual failure rate though it is widely believed to be 3% per year regardless of age based on an almost 40 year old small Canadian study when smoke alarms where still a new invention. Smoke alarms have come a long way since 1980’s, and in theory, the electronic components in a smoke detector should last at least 30 years. But a smoke detector could fail at any time and fire safety officials recommend changing them every 10 years because that provides a reasonable margin of safety and after that time their sensors can begin to lose sensitivity.

The test button you have been dutifully pressing each year only confirms that the battery, electronics, and alert system are working; it doesn’t mean that the smoke sensor is working. To really test the sensor, you need to use an aerosol can of smoke alarm test spray that simulates smoke. Fire-safety officials have long believed that the leading cause of smoke-detector failure is a power-source problem, primarily dead or missing batteries since most detectors are battery powered. The result has been the campaigns to get consumers to change their batteries twice a year when they reset their clocks. But many of those experts are increasingly concerned that some detectors may fail to work because they are simply too old. According to the Fire-protection association smoke detectors’ sensitivity to smoke tends to change over time. Sometimes becoming more sensitive and causing more nuisance alarms, sometimes becoming less sensitive and not alarming when there is a fire.

The U.S. Fire Administration for Homeland Security, the National Fire Protection Association (NFPA), the National Electrical Manufacturers Association (NEMA) and the Red Cross agree after working for 87,000 hours or 10 years in normal environmental conditions in the home it is time to replace your smoke alarms. I replace my smoke alarms at the recommended interval.

Every home should have smoke alarms, and all homes with oil, natural gas or propane burning appliances such as a furnace, water heater, stove, cooktop or fireplace should have a carbon monoxide monitor. If you have an all-electric home you do not really need a carbon monoxide alarm unless you operate a generator during power outages. If you are replacing your smoke alarms, it is a good time to consider your options.

There are two basic types of residential smoke detectors, ionization and photoelectric. Ionization models are excellent at detecting the small particles typical of fast, flaming fires, but tend to be poor at detecting smoky, smoldering fires. Ionization units are generally prone to false alarms from burnt food and steam-classic causes of annoying false alarms. Photoelectric smoke alarms are excellent at detecting the large particles typical of smoky, smoldering fires, but all were poor at detecting fast, flaming fires. Photoelectric units are less prone to false alarms from burnt food and steam, so you can mount them closer to kitchens and bathrooms.

By far, most residential smoke alarms are ionization sensor models; though I’m not sure that is the best choice. These types of smoke detectors contain a very tiny amount of radioactive material, americium-241 embedded in a thin gold foil in an ionization chamber. An ionization chamber is very simple. It is basically two metal plates a small distance apart. One of the plates carries a positive charge, the other a negative charge. The radioactive material is contained within a laminated material thick enough to completely retain the radioactive material, but thin enough to allow the alpha particles to pass. Small particles from fires and smoke interfere with the movement of the alpha particles and the circuit is broken the smoke detector alarms.

Photoelectric smoke alarms use a T-shaped chamber fitted with a light-emitting diode (LED) and a photocell. The LED sends a beam of light across the horizontal bar of the chamber. The photo cell will generate a current, when exposed to light. Smoke will interfere with the circuit, but they can be insensitive to small particulates.

Combination smoke and carbon monoxide alarms are recommended those using propane or natural gas appliances or fireplaces in their homes. These alarms can detect smoke as well as carbon monoxide. Typically, these are ionization and the carbon monoxide monitor uses an electrochemical sensor that had a predicted life of 7 years initially, but has improved over time and is now calibrated at 10 years. If you buy a combination ionization and carbon monoxide alarm, you might want to also get a separate photoelectric unit to be fully protected of use a dual-sensor smoke alarm.

Dual-sensor smoke alarms. These combine ionization and photoelectric technology to save you the hassle of installing two separate smoke detectors. Fire protection authorities recommend that both ionization and photoelectric smoke alarms be used together to help ensure maximum detection of the various types of fires that can occur within the home. Ionization sensing alarms detect invisible fire particles (associated with fast flaming fires) sooner than photoelectric alarms. Photoelectric sensing alarms detect visible fire particles (associated with slow smoldering fires) sooner than ionization alarms.

Each time I replace my smoke alarms, I check to see if they have come out with a combo ionization, photoelectric and carbon monoxide alarm. This time I found one, the Universal Security Instruments AMIC1510SC 3-in-1 Sensing Plus® Hardwired Smoke, Fire & Carbon Monoxide Alarm is one of few combination detectors that has both photoelectric and ionization sensors for smoldering and flaming fires in addition to a carbon monoxide sensor in a hardwired unit. It is pictured above.  This is the deluxe model (there is a cheaper hardwired model) with several bells and whistles I wanted including a 10 year battery.

Sunday, October 2, 2022

St. Katherine Drexel

 In 2015 St. Katherine Drexel Parish and School requested and obtained a special use permit to build a church with a 1,000 seat sanctuary and 550 seat fellowship hall and classrooms for 260 children in K-8th grades, administrative offices, rectory, meeting areas for community groups and related facilities on a 28 acre parcel of land on the north west corner of Waterfall Road and Route 15 across from the 7/11. Because the land is in the Rural Crescent, the St. Katherine required a special use permit.

The project was proposed and approved as using a private well and a septic system, despite the fact that at the time the Health District did not believe that the site could support a septic system adequate to service the Church and School.  Now, the Catholic Diocese of Arlington in the person of the Brian Prater of the law firm of Walsh, Colucci, Lubeley Walsh has requested an amendment to the special use permit to allow St. Katherine Derexel Church and School to connect to the public sewer system and if necessary connect to the public water supply.

In his presentation to the Planning Commission Mr. Pratter stated that the soils on site would not support a traditional septic system and that an alternative on-site sewage system would probably fail. Nothing has changed since the original application. The USGS characterization of the soils in this area date back more than 30 years. In 2015 I pointed out at the public meeting at the Evergreen Firehouse that the soils on site were a mix of hydrogeologic group B and C and at the time the health district believed that on-site septic system would be problematic. In 2015 the representative of the Catholic Diocese of Arlington assured the those attending that community meeting that they were very experience at overcoming these type of challenges. Yet, here we are.

The soils underlying the site have not changed it is still group B and C which both underly the western part of Prince William County. B consists of sedimentary rocks of the Culpeper Basin. The predominant rock types are conglomerates, sandstones, siltstones, shales, and argillaceous limestones. Rocks within hydrogeologic group B tend to have moderate to excellent water-bearing potential because it is a fractured rock system with very little overburden very poor for septic. Hydrogeologic group C is interspersed throughout the area of groups B and consists of igneous rocks (basalt and diabase) of the Culpeper Basin. The predominant rock types are basalt, sandstone, siltstone, diabase, hornfels, and granofels. Rocks within hydrogeologic group C tend to have generally poor water-bearing potential because of the wide spacing between fractures, mineralization of fractures, and random fracture orientations. In other words, unless you hit a good fracture, you are likely to have a dry well and these wells tend to become mineralized and loose flow over time.

Mr. Prater lead the PW Planning Commission to believe that “the applicant” has recently discovered the issues with the on-stie soils. That is not true. In 2015 they knew the soils were not appropriate for a traditional septic system, the question is when did they stop knowing. The proposed church and school will cover over 20% of the land with buildings, parking, walkway and other impervious surfaces that will change the hydrology of the site reducing ground water recharge in the area around the school at the same time that the school and church will increase groundwater use to an estimated 12,500 gallons a day (3-4 million gallons a year) according to the Pacific Institute. That is equivalent to building around 50 homes on the 28 acres. With reduced groundwater recharge in the immediate area of the school from all the paving, there is a real possibility that the pumping from the school will create a large cone of depression to draw water from adjacent properties or greater depth that could cause nearby existing wells to go dry, and people will have homes without water –worthless. 

The plan may well have been to buy inexpensive land that could not be connected to the public water and sewage, get a special use permit making assurances that they have the septic and well issues handled. Wait seven years until consultants, staff and the planning commission turn over then appeal for an amendment to the special use permit because the site is unsuitable for septic and might need public water. For penitence the Catholic Diocese of Arlington should fund a community septic and well repair fund. There is a need for such a fund in Prince William County, a quarter of a million should do.