Sunday, August 7, 2022

Poor Communities get help Accessing Federal Funds

Last week the U.S. Department of Agriculture (USDA) and the U.S. Environmental Protection Agency (EPA) announced the Closing America’s Wastewater Access Gap Community Initiative. The initial funding for the effort will be $5 million and will give poor and small rural communities access to a wide range of assistance in accessing a wide array of federal programs.

The USDA-led network brings together twenty federal agencies and regional commissions to help rural communities create economic opportunity by accessing resources and funding that match their unique needs and priorities. These monies were invisible to and unavailable to these communities. It takes trained experts to access federal programs designed to help communities. So, the federal government had to create a program to help access other federal programs. 

EPA and USDA experts will work directly with local officials to draft detailed proposals including needs assessments and project lists required by state governments under the federal programs. This need for technical expertise has effectively shut out these communities from accessing financial assistance for their water and wastewater projects.

The new initiative will be piloted in 11 communities across the country where residents lack basic wastewater management that is essential to protecting their health and the environment. Around 2 million Americans lack access to running water and/or a flush toilet. This number includes the estimated 560,000 homeless population in our cities and communities that many see daily, but there are over 1,400,000 mostly rural Americans who are housed but lack running water and basic indoor plumbing. Many more live with wastewater infrastructure that is ineffective and puts people’s health at risk. 

Access to sanitation is the most serious water access concern in the rural South- rural Mississippi, Alabama and the Delta region. A septic system that can function in this type of black soil with a shallow water table can cost $30,000 or more to build and is called an AOSS- alternative on-site sewage system. Though very effective, these systems also require regular service to remain functioning. Instead, some residents use PVC pipes to remove wastewater away from homes, sometimes right into their back yards, a practice known as “straight-piping.”

Straight-piped systems, failing septic systems, and wastewater lagoons generate considerable public health impacts, including the resurgence of water-borne illnesses believed to have been eradicated in the United States. The poor do not have the resources to maintain water and septic systems. This is where funding from the infrastructure bill should go. Helping the invisible and housed poor.  

The Closing America’s Wastewater Access Gap Community Initiative will help communities access financing and technical assistance to improve wastewater infrastructure. EPA and USDA are launching the initiative in:

  • Lowndes County, Alabama.  The  White Hall community has inadequate wastewater infrastructure. Local challenges include failing septic systems, straight pipes and inadequate centralized sewer capacity.
  • Greene County, Alabama. Local challenges include failing septic systems and the use of straight pipes, resulting in raw sewage on the ground, surface water, and seepage into ground water. The rural nature of the county, geology (black belt soils) and economic conditions, has made centralized wastewater systems a challenge.

Access to adequate wastewater infrastructure is a basic human right, but for too many of my constituents, generations of disinvestment have led to broken and failing wastewater systems that put the health of our communities at risk,” said U.S. Representative Terri Sewell (AL-07).

This joint initiative between the EPA and USDA will be instrumental in our fight to improve wastewater infrastructure for our most underserved communities and is part of the Rural Partners Network that introduces a new way of doing business: a collaboration among federal agencies meant to improve access to government resources, staffing and tools.

The Rural Partners Network puts federal staff on the ground to support designated, economically challenged communities. Known as “Community Liaisons,” these federal employees provide local leaders with the expertise to navigate federal programs. Community Liaisons help build relationships and identify additional resources to get the job done. In addition, the federal agencies designate key points of contact who focus specifically on rural strategies, improving visibility and attention to rural issues. It is hoped as their work progresses, the lessons learned will inform future federal rural policy development and investment strategies.

Wednesday, August 3, 2022

Dominion Adds Batteries to the Grid

from Dominion Energy

Last week Dominion Energy announced that it energized an independent battery systems totaling 12 megawatts at the Scott Solar facility in Powhatan County. "Battery storage is an integral component to the clean energy transition in Virginia, supporting grid reliability for our customers during periods of high demand and by helping to fill gaps due to the inherent intermittency of solar and wind power," said Ed Baine, president of Dominion Energy Virginia. "These battery systems will help us better understand how best to deploy utility scale batteries across our service territory to support our goal of net zero emissions by 2050."

Energy storage is key to grid reliability, continued solar and wind expansion, and achieving net zero emissions and more battery energy storage projects are under development by Dominion Energy. The company has two other battery storage pilot projects in its portfolio – a 2-megawatt battery in New Kent County that was commissioned in late February and a 2-megawatt battery in Hanover County that is scheduled to become operational later this year. All three projects were approved by the Virginia State Corporation Commission (SCC) in February 2020. 

The 12-megawatt battery at the Scott site can power 3,000 homes for up to four hours. The batteries are set up to charge and discharge daily. They are not designed as backup power, but are designed as supplemental power during periods of short, high-demand. These pilot projects will allow Dominion Energy to learn how to balance a grid using batteries and intermittent net zero generation.

Sunday, July 31, 2022

Overdrawn at the Energy Bank

Loudoun County has courted data and cloud companies and making development and land use decisions that has resulted in Loudoun County having the highest concentration of data centers in the world. These data centers provide a very significant amount of revenue to the county through real estate and business personal property taxes. 

The computer equipment in the existing data centers provides significant personal property tax revenues to the County’s budget. However, the value of those assets depreciates each year. Unless that equipment is constantly replaced the revenue will diminish over time.

In recent years, Prince William County has copied Loudoun County’s approach and undercut Loudoun County’s rate for the data centers of the personal property taxes on the computer servers. Data center growth in Prince William County has increased significantly and is poised to take off.  The proposed PW Digital Gateway is large enough to accommodate 33.4 million square feet of data centers. Which exceeds that data center square feet currently existing in Loudoun County.

Now, Dominion Energy has informed Loudoun County that it will not be able to provide power to new data center projects in Ashburn at this time. They lack  adequate transmission capacity and building it could delay new data centers coming online by a year or more.

Dominion Energy is required to provide power to customers. They do not have the option. However, infrastructure has to be built to meet the demand.  According to the PMJ  Data Center Alley… is experiencing unprecedented load growth driven by increases in data center load that started in 2018 and is expected to continue growing post 2027.” From 2018 to date, Dominion has had 44 requests to serve 2,050 MWs of load increase through the summer of 2025. These projects have to be integrated into the grid and so the PMJ, the regional transmission organization, has to be involved.

Once the PJM load forecast was updated, the system showed a need for reinforcements through additional source(s) to serve the load increase from the 500 and 230 kV transmission system nearby. PJM identified the need for additional transmission reinforcements in the area. Because the area is constrained on all 230 kV inlet transmission segments to serve the size of load and data center load has a flat profile throughout the day, power flow control or non-wires solutions can not solve the problem in this area. There is no work around. Dominion needs to run more 230 kV transmission wire, and the next fight will be about where they were going to route this power. The Data Centers required tower after tower of 500 and 230 kV  transmission wires.

After driving the 40% increase in power usage in Virginia the data centers have reached the limit of what Dominion Energy can supply on their existing infrastructure. I personally object to paying for the construction of infrastructure to supply the power to Data Centers. That expense is added to the Dominion cost basis and all our electric rates.  PMJ says will have to build more transmission for the data centers to assure system reliability. Using an old rule of thumb (that may be out of date), the current forecast looks like it will require about 25 more overhead lines to deliver the current projected power need. The data centers are turning Northern Virginia into New Jersey with the industrial blight of running power transmission lines to feed the data centers and massive industrial buildings. 

Though Dominion Energy has made significant investments in new infrastructure to meet the growing demand for electricity from the Data Center industry, it has not kept up with the surging growth of data center demand for power. According to Dominion Energy, "…the transmission constraints in a pocket of eastern Loudoun County that will impact new connections for large customers. This will not impact residential or small business customers." 

There has been some speculation that this development will benefit Prince William County data center development; however, looking at the transmission maps that Dominion has published for various public hearings it appears that that the same constraints will have to be addressed here. Also, the transmission lines will run through our communities. 

Historic Prince William has posted 266 Pictures of Prince William County taken from a helicopter on Friday, March 29, 2019 between 2pm and 3pm.  Take a look at the county here

Wednesday, July 27, 2022

Buying Good Water- a House with a Well

For most of the first 25 years of our marriage we lived in rental apartments. We talked about someday owning a house. My husband wanted a big house on lots of land in Virginia, his home. I generally dreamed of a house of more modest size near whatever city we were living in at the time.  After living a decade and a half in California with constant water restrictions and crisis, water became the number one item on my list (followed by high-speed internet). So, we ended up in Virginia in his someday house with a well with my water supply.

There is a whole lot beyond being clear and tasting good that makes water satisfactory.  The first thing to verify is that the well is constructed properly. That is fairly simple, though there are no national standards for construction of private water wells, in Virginia the Department of Health well construction regulations went into effect in 1992. So, buy something with a well drilled after that.  A simple trip to the local health district allowed me to get the well completion report for all the houses we were considering.  Well built to current standards-check.

The well completion report  tells you how old the well is, how deep, what the well yield was at completion. I was also looking for a well with a stabilized yield greater than 6 gallons a minute in the right kind of geology because geology impacts how a well ages. If you are buying an older well (still built after 1992) check the water level and yield - yield diminishes over time. You will have to hire a well driller to do this. 

There are three considerations for a private well- the well and well system, the water quality and the water quantity. Failure in any of these can impact your life and the value of your home. The well is essentially a hole in the ground. Shallow wells (those less than 50 foot deep) are  dug or bored into the ground and have larger diameters (2-4 foot). Shallow wells are more prone to contamination and drought and bored wells have the shortest life. Deeper wells are called drilled wells because they are drilled into the ground to depths from 50-450 feet or more and because of the need for drilling rigs cost much more to build. The diameter of a drilled well is 6-8 inches. 

Only buy a home with a drilled well. Generally, drilled wells provide a safer source of drinking water, and are less often impacted by drought. In igneous and metamorphic rock systems like the Piedmont of Virginia, the fractures and fault lines formed in the rocks store and transmit groundwater. The size and number of water bearing fractures varies and there is a wide variation in well yields from under 1 gallon per minute to over 50 gallons a minute depending on location and specific site geology. Fractures can become fouled with mineral deposits or iron bacteria or simply go dry over time. 

Aquifers can go dry unexpectedly, but all wells will fail over time. The lifespan of a drilled well is assumed to be 20-50 years, but varies tremendously based on site specific conditions. I personally know of a drilled well that lasted 65 years, but if you are buying a home with a well over 20 years old you will need to budget for drilling a new well. Make sure that the cost is considered and that the property has another location to drill a well.  

The well system consists of the well, the well casing, the inlet for water, and the pumping system. The casing is the structure around the well hole to prevent its collapsing. It could be a steel or plastic casing or an open hole in the bedrock. In this part of Virginia, the Piedmont, the top of the well is lined with steel for 50 feet and then the well is open in the bedrock allowing the water to flow into the well. A steel well casing will rust over time and eventually collapse. The well casing should be 1-2 feet above the land surface to make sure that during storms and flooding that nothing washes down the well. There should be no holes or cracks in the visible portion of the casing and the well cap should be tightly bolted closed.

The essential components of a modern drilled well system are: a submersible pump, a check valve (and additional valve every 100 feet), a pitless adaptor, a well cap, electrical wiring including a control box, pressure switch, and interior water delivery system. There are additional fittings and cut-off switches for system protection, but the above are the basics and each and every component must work properly for your well to function properly.

The pumping system includes the pump, piping and electrical connections to pump water from the well into the house and a pressure tank to maintain constant water pressure in the house. Shallow wells usually use centrifugal pumps and are often located in a pump house or the basement. Drilled wells have submersible pumps. The pump and pumping systems are the most likely components to fail in a well. The average life of a submersible pump is variously reported as 12-15 years, but many pumps fail in the first few years. 

In addition, in order for a well to keep supplying water to your home the components within the basement must all continue to work. These components provide constant water pressure at the fixtures in the house and the electrical switch that turns on the pump. For a drilled well if there is any other equipment beyond the pressure tank, it is a water treatment system, and you need to test the water before and after the treatment. 

The pump moves water to the basement water pressure tank, inside the tank is an air bladder that becomes compressed as water is pumped into the tank. The pressure in the tank moves the water through the house pipes so that the pump does not have to run every time you open a faucet. Bladders and electrical switches will fail over time and valves and switches and impellers on the pump can break, foul or find any number of ways to fail. You have to assume that pump systems that are older than 12 years are on borrowed time. It does not mean that a pump system cannot last 25 years or more, but I would not bet on it. 

When buying a home with your own water supply you need to consider the construction, condition, age and location of the well in addition to water quality and quantity. Geology plays an important role in the water quality and quantity.  Clay loams or silty clay soils filter pollutants and protect an aquifer. A shallow water table and fractured bedrock may provide larger quantities of water, but the shallow fractured rock systems are susceptible to contamination from the surface. 

The specific geology and water quality will determine the life span of a well. So pick your desired geology. Within the three counties around here there are significant variations in the geology. There is an area in Loudoun County that is high in iron and an area nearby that is karst terrain. The groundwater in karst terrain is easily impacted by surface contamination and is potentially subject to sinkholes. No. There are areas with very high natural iron and manganese content, areas of extremely hard water and areas with soft or aggressive water. No, no and no.

Within Prince William County Virginia there are several distinct geologic provinces that will have different groundwater characteristics. The northwestern part of Prince William County down the hill from Bull Run Mountain, consists of sedimentary rocks of the Culpeper Basin. The predominant rock types are conglomerates, sandstones, siltstones, shales, and argillaceous limestones. This geology tends to have moderate to excellent water-bearing potential because it is a fractured rock system with very little overburden. The highest reported yields in the county are from wells in this geology. In other parts of the county there are deep wells in the diabase that tend to have reliable lower yields. I choose fractured siltstone as my targeted geology. 

The issue of whether water is safe to drink is separate from whether the water is free of unpleasant contaminants like iron, manganese, chloride, and low levels of hydrogen sulfide or the groundwater has been contaminated. The well must be tested. Before you buy test the water for all primary and secondary contaminants in the Safe Drinking Water Act. In addition to testing the water for any nearby likely sources of contamination. I was only interested in purchasing a home with water that did not need any treatment. There is a big difference to me between fixing a problem that develops over time and buying that problem. 

Water chemistry is a tough category to give rules of thumb. Your best option is to do a broad scan of the well water quality. There are screening packages available from U.S. EPA certified laboratories like  National Testing Laboratories that screen water wells for all the primary and secondary contaminants in the Safe Drinking Water Act.

The WaterCheck with pesticides package from National Testing Laboratories is a broad stroke test, testing the water for 103 items including Bacteria (Total Coliform and E-Coli), 19 heavy metals and minerals including lead, iron, arsenic and copper (many which are naturally occurring, but can impact health); 6 other inorganic compounds including nitrates and nitrites (can indicate fertilizer residue or animal waste); 5 physical factors including pH, hardness, alkalinity; 4 Trihalomethanes (THMs) and 47 Volatile Organic Chemicals (VOCs) including Benzene, Methyl Tert-Butyl Ether (MTBE) and Trichloroethene (TCE). The pesticide option adds 20 pesticides, herbicides and PCBs.  This testing can be done for a few hundred dollars.    

The report they produce tell you if the contaminant was detected, if detected if it was below or above the EPA standard under the Safe Drinking Water Act, and finally if the contaminant was above the standard if it was above an enforceable MCL (maximum contaminant level). If sodium is present it should be under 10-20 mg/L. Any higher and you have salt water infiltration or the well system might have a water softener that is obscuring many of your results and you need to test again ahead of the water treatment. The nitrate level should be well below the EPA standard of 10 mg/L closer to the background level (around 2 mg/L in northern Virginia). Higher than 5 mg/L tends to be related to septic performance either at your house or a neighbors but can also indicate historic use of fertilizers or animal waste storage. If these problems exist, it will only grow worse with time.

I like hard water so anything between 100 mg/L and 180 mg/L is fine by me. Higher though, could be difficult to live with and should be avoided. Too low and you might have aggressive water (slightly acidic) which has a whole bunch of other problems or once more a water softener is installed and you need to retest.  

All trihalomethanes, solvents (organic volatiles) and hydrocarbons should be non-detect. None of these are naturally occurring and even low levels are an indication of a source of industrial contamination. A trace of TCE in a well was the first symptom of what turned out to be a Superfund site in Loudoun County. Run away. Same is true for the pesticides and other organic analytes. 

Metals (inorganic analytes which are naturally occurring) should all be on the low end of the allowed range, except for lead which should be non-detect after the first flush. There is no safe level of lead and it is not naturally occurring in groundwater. Cadmium, lead and mercury are metals that are found at relatively low concentrations in the environment. Lead is nearly immobile in soil so it does not enter groundwater by any natural pathway. It generally appears from the deterioration of metal plumbing and well equipment that contains low levels of lead. Lead in groundwater can also be a result of industrial contamination. Run away very fast. 

Sunday, July 24, 2022

You are Responsible for Your Well Water

Although the majority of the United States' population gets its drinking water from pubic systems, the Environmental Protection Agency, EPA, estimates that more than 23 million households rely on private water supply system (i.e. wells, springs, and cisterns) for drinking water. Most of these are private wells. My own home is supplied with water from a drilled well. EPA does not regulate private drinking water systems- your on your own in making sure the water in your home is safe to drink.  Many states have well regulations, the vast majority of which are construction standards for new wells.

The concentration of private wells is not evenly distributed throughout the country, obviously private wells tend to be in rural or semi-rural areas. The Census Bureau stopped collecting information specific to private well use in 1990, so much of the national data is extrapolated from 1990. Virginia Tech reports that over 22% of the Virginia’s population or 1.7 million people are dependent of private drinking water wells for their drinking water.

The quality and safety of private domestic wells, are not regulated under Federal or, in most cases, state law. In Virginia only the construction is regulated and wells are only required to demonstrate the absence of bacteria, the most basic form of potability at the completion of the well construction process. The U.S. Environmental Protection Agency Safe Drinking Water Act (SDWA) does not regulate individual households.

As a result, individual homeowners are solely responsible for maintaining their domestic well systems and for any routine water-quality monitoring that may take place. Just because your water appears clear doesn’t necessarily mean it is safe to drink. You cannot taste bacterial contamination from human and animal waste, nor taste nitrate/ nitrite contamination. Many chemical contaminants cannot be tasted or smelled at levels that can impact your health. Since bacterial contamination cannot be detected by taste, smell, or sight, all drinking water wells should be tested at least annually for Coliform bacteria and E Coli. Testing is the only way to detect contamination in your water.

In the past it was not recommended to test your well, it is now widely recommended (by the department of health and University Extension programs) that private well owners test their wells annually (at least for bacteria), yet the vast majority of well owners still do not. Private well owners often lack a basic understanding of the groundwater that supplies the wells and the mechanical components of their well systems and turn a blind eye to maintaining their water systems.  

Groundwater comes from rain, water and snow melt percolating into the ground. Typically, the deeper the well the further away is the water origination and the older the water. The groundwater age is a function of local geology, the amount of precipitation and the rate that water is pumped out of the aquifer. Geology also determines the ease with which water and contaminants can travel through an aquifer; microorganisms in the soil and from wildlife and spilled chemicals or contaminated runoff can travel into groundwater supplies through cracks, fissures, and other pathways of opportunity like fractured rock systems. The land surface through which groundwater is recharged must remain open and uncontaminated to maintain the quality and quantity of groundwater.

The quality of your water will be determined of the source of the groundwater, the ability of your local geology to protect or impact your aquifer and the absence or presence of a potential local source of contamination. First of all let me say that according to the US EPA actual events of groundwater contamination have historically been rare and typically do not occur at levels likely to pose significant health concerns. This fact is the basis of the EPA and state health departments’ acceptance of private and unmonitored use of groundwater for drinking water purposes for a significant portion of the United States. However, as population density increases and we use more and more chemicals, pesticides and drugs, there are more opportunities to contaminate our groundwater. Because I am a retired environmental engineer I tend to focus on threats to the groundwater and worry about my groundwater quality more than most.

The most common sources of pollution to groundwater supplies come from two categories; naturally occurring ones and those caused by human activities. Naturally occurring contamination are produced from the underlying soil and rock geology. Microorganisms in the soil can travel into groundwater supplies through cracks, fissures, and other pathways. Nitrates and nitrites from the nitrogen compounds in the soil can also enter the groundwater. From the underlying rocks radionuclides and heavy metals can enter the groundwater. There are areas with natural occurring arsenic, cadmium, chromium, lead, selenium and fluoride. While many natural contaminants such as iron, sulfate, and manganese are not considered serious health hazards, they can give drinking water an unpleasant taste, odor, or color.

Human activities can also introduce contaminants into the groundwater. Bacteria and nitrates can be caused by human and animal waste. Improperly constructed and sealed wells can allow surface contamination to enter the well. Improperly maintained septic systems containing human waste and any chemical you flush down the drain, horses, and backyard poultry can contaminate the groundwater. Leaks from underground storage tanks, surface disposal of solvents, motor oil, paint, paint thinner, or nearby or historic landfills or industrial operations can contaminate groundwater. A confining geological layer can protect groundwater from surface contaminants more effectively than a fractured rock system or sand and gravel, and there is very limited natural protection in karst terrain. In Virginia, where there are rich supplies of groundwater our aquifers can be very susceptible to contamination in certain locations.

Often well owners lack access to objective information and a framework for understanding problems and help in solving the problems with their wells.  Because private drinking water wells serve more than a fifth of its population, Virginia  has taken steps to assist private well owners monitor, understand and maintain their wells. The Virginia Household Water Quality Program (VAHWQP) was created by the Virginia Cooperative Extension to provide affordable water testing and education about private water wells to residents of the Commonwealth. For $65 samples are analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria. These are mostly the naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion. Though this is not an exhaustive list of potential contaminants, these are the most common contaminants that effect drinking water wells. Though Prince William's clinic was in the spring, Loudoun, Fairfax, Culpeper and Fauquier Counties are are all having clinics this fall. You should make a point to participate in the program. It is an easy way to check your well every year.

Wednesday, July 20, 2022

The Wells of Virginia 2021

Private drinking water wells serve more than a fifth of Virginia’s population or 1.7 million residents.   Virginia created the Virginia Household Water Quality Program (VAHWQP) to provide affordable water testing and education about private water wells to those residents of the Commonwealth. Extension Offices hold drinking water clinics and provide information to assist private well owners in understanding and maintaining their wells. 

The quality and safety of private wells are not regulated under Federal nor, in most cases, state law. In Virginia regulations control only construction and the absence of bacteria at the time of a well’s completion. The U.S. Environmental Protection Agency Safe Drinking Water Act does not regulate individual households. As a result, individual homeowners are responsible for maintaining their own water supply and ensuring the quality of the water for their family.

The Virginia Household Water Quality Program was, originally created in 1989, was relaunched in 2007 with a USDA grant. In 2011 the program was expanded under another USDA grant to subsidize testing, quantify bacteria, add metals, and begin research out of Virginia Tech. Now the program is self-sustaining with clinics held in 91 of the 96 counties in 2021. The analysis is done by the Virginia Tech laboratory and research utilizing the data is being pursued by graduate students.

In all the Virginia Household Water Quality Program clinics the water samples are analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria, and last year cost $65 in Prince William County. These are mostly naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion. Though not an exhaustive list of potential contaminants, these are the most common contaminants that effect drinking water wells.

Though about 600,000 of Virginia households with 1,700,000 residents or 22% of the Virginia population have private wells, only around 2,785 households chose to participate in the Virginia Household Water Quality Program clinic in 2021 and may not be representative of all private drinking water wells in the Commonwealth. Nonetheless, the data collected over the past 15 years is the one of the largest databases on private drinking water wells available. Well water quality is driven by geology, well construction and condition, nearby sources of contamination, and, within the home, water treatment devices and composition of plumbing materials.  

from Virginia Tech: contaminants found above the SDWA limit

Overall, the statewide sampling last year found that just under 40% of the wells have coliform bacteria present, and almost 6% have E. coli bacteria. Though 22% of wells were found to have acidic water (low pH) about 6% of homes have first flush lead levels above the EPA safe drinking water standard maximum contaminant level for lead and copper. Lead and copper leach into water primarily because of corrosion of plumbing and well components but can also result from flaking of scale from brass fittings and well components unrelated to corrosion. Copper and lead predominately come from the pipes. Over time older pipes and fixtures corrode or simply wear away and the lead and other corrosion material (like rust) is carried to the drinking water. Time and water do cause corrosion, but this can be aggravated by the pH of the water or other changes in water chemistry. The amount of lead corroded from metal plumbing including faucets with brass interiors generally increases with increasing water corrosiveness.

About 36% of households have elevated sodium exceeding the EPA Safe Drinking Water Act limit. This could be a result saltwater infiltration from natural or man-made sources (like road salt) or could indicate that water softeners are adding too much sodium to the water. Of the 2,785 participants in 2021, 41% report that they NEVER tested their water before and 32% had tested only once (presumably at purchase). About 43% of participants have participated in the VAHWQP clinic before.  Virginia Tech recommends annual testing of well water to make sure it is safe to drink, and you have the appropriate treatment system(s).

Sunday, July 17, 2022

Drought and the Potomac River

For the first time in years,  the Interstate Commission for the Potomac River Basin, ICPRB, says there is an above normal probability of needing to releases water from the Washington metropolitan area’s back-up water supply reservoirs over the summer and fall. The need for water from the Jennings Randolph and Little Seneca reservoirs is triggered by low flows in the river resulting from a combination of low summer precipitation and low groundwater levels. The average precipitation in the Potomac Basin is below normal for the past 12 months. 

Between 2014-2018, total daily withdrawals between Seneca Pool and the Little Falls Dam averaged 354 million gallons/day and ranged between 257 and 503 million gallons/day (Ahmed et al. 2020, Ahmed, pers. comm.). While the average daily withdrawals are roughly 5% of the long-term river flow at little falls, they are a substantially larger percentage of the flow during dry and drought periods.

According to the ICPRB the Washington metropolitan area water utilities are planning to meet the  potable water demands in the face of increasing population and use. “Current demands would suck the river dry during a drought of record without the creation of reservoirs used to bolster river flows during extreme low flow. “ The stored water is used and managed by a process that provides water for each of the major independent water suppliers serving the area. A crucial aspect to meeting the drinking water demands of the region is preserving and protecting the ecological health of the Potomac River, leaving enough water in the river segment downstream of intakes for the river to reach the Chesapeake Bay. These so called minimum flow levels have been established for that segment of the river.

The 1978 Potomac River Low Flow Allocation Agreement continues to serve to allocate water during  drought periods based on each utility’s usage during the previous five winter seasons while preserving a 100 million gallons/day flow-by to maintain the river’s ecology. Loudoun Water has recently built its own river intake upstream and is being incorporated into the agreement which turns out not to be entirely straight forward. 

As part of an ongoing process of updating the agreement and water supply management, the ICPRB recently held a two-day Environmental Flows Workshop to assess possible new approaches for determining sustainable environmental flows and the data, tools, and types of assessment needed to create new flow rules that protect the Potomac as the climate and ecology continue to change. This is all intended get stakeholder buy-in and to ensure the Potomac can meet ongoing needs while retaining its living resources and other values.

It is possible that River median flows at the measuring points of Little Falls is changing and may be decreasing due to population growth and associated land use changes that have taken place this century. Population growth accelerates loss of forest and farmland, hardens surfaces, increases demand for water. Urbanization can significantly alter a river’s flow. Impervious surfaces of roadways, sidewalks, parking lots and building foundations increase stormflow peaks, frequency, and duration, impart greater erosive power to the water by increasing velocity, and reshaping stream contours. Rivers are sustained by groundwater between in drier periods, but urban and suburban development reduces recharge of the groundwater. Deforestation increases the proportions of rainfall running off the landscape instead of seeping into the ground where it can be taken up by plants or enter the groundwater. All this needs to be accounted for in allocations and ecological flows.

The Potomac River starts life as a spring at the Fairfax Stone in West Virginia. The river flows approximately 385 miles to the Chesapeake Bay increasing in size and flow from its tributary streams and rivers in West Virginia, Maryland, Pennsylvania, Virginia, and the District of Columbia. The Potomac River grows to become the Chesapeake Bay's second largest Tributary. The River provides drinking water to those living within its watershed, irrigation water , and the water for power plants and data centers.

The Potomac River is one of the least dammed large river systems in the Eastern United States. The combined storage capacity of all major reservoirs upstream of Washington, DC makes up less than 7% of median flow. Nonetheless, the Potomac River’s flow needs to be managed to assure the river supplies for drinking water to the region and the essential environmental services. The ICPRB was created to manage the water withdrawals from the Potomac to ensure that essential services like wastewater assimilation and habitat maintenance. The ICPRB monitors river flows and withdrawals to ensure the Potomac River will never again run dry.