Sunday, May 30, 2021

The Rural Area 2021

At their May 5, 2021 meeting, the Prince William Board of County Supervisors unanimously voted to adopt a Purchase of Development Rights Program (PDR) for the Rural Area. The Board unanimously denied the Rural Area Plan; however, for mixed reasons and remanded the Residential Clustering and Transfer of Development Rights back to the Planning Commission to be reworked. Also, under consideration and sent back to the Planning Department, is expanding the data center overlay district. There are landowners in the rural area interested in creating a 400-acre data center district in the Rural Area along Pageland Lane.

Purchase of Development Rights Program will allow for property owners in the Rural Area with 20+ acres of contiguous A-1 zoned, Agricultural land to submit an application to sell their development rights to the County. The Program is entirely voluntary and will allow land owners to retain ownership of their land while conserving it for natural, historical or agricultural purposes. Pricing and funding of the program are big issues here and will determine the success of the program. The value of land is very much dependent of zoning and demand.

Sent back to the Planning Department for were the proposals for the creation of a new use classification and zoning of Conservation Residential, CR-3 and CR-5 within select areas of the Rural Area. The Conservation Residential areas are where cluster developments would be built, would allow extension of sewer into the Rural Area and would require 60% of the property to be dedicated in a permanent conservation easement. The buffer around the entire property is intended to be placed in a permanent conservation easement.

The other Planning Department recommendation sent back to be reworked was the Transfer of Development Rights (TDR) program. Planning Office staff has recommended several Regional Activity Centers in both the Development Area and the Rural Area as receiving areas for TDRs. Plans for TDR programs sound very straightforward; development is transferred from one location to another. However, in practice they have often been difficult to implement.

The idea that a TDR program would, by itself, protect open space, and preserve farming while helping to create appealing village centers in other parts of the county by simply offering a mechanism for moving development around is not realistic.  TDR programs must be tailored to the specific political, economic and geographic circumstances of their location. The economic demand and return for selling and purchasing the development rights must be high.

This commitment to the larger goals of the comprehensive plan and to the particular resources being protected is essential to overcome challenges.  A study done at Cornell University found that for a program to be successful a TDR use needs to be “by right” for developers. In addition, it is important that higher density or zoning changes not be given away “for free,” by the Board of Supervisors or Planning Commission outside the TDR program. Finally, how the market actually functions is important. The Cornell study found that local government needs to facilitate the market TDRs by providing information, providing a clearinghouse or registry for the market, and collecting and analyzing data from the program. The Prince William County Board of Supervisors has a history of giving away rezoning and increased density.

Though, it is often believed that when you own land you can do what you want with the land, but that is not true. Zoning determines use and value of land. It is not in the public interest to allow anyone to put a hazardous waste dump in their backyard, build a manufacturing plant along the Occoquan, mine uranium next to the water supply for the county or other undesirable activities.

Virginia law requires every governing body to adopt a comprehensive plan for the development of the lands within its jurisdiction. So, each county and city has created a comprehensive plan. These plans are reviewed every five years, to ensure that they continue to be responsive to current circumstances and that the citizens of the county continue to support the goals of the plan. Exceptions to the existing plan are granted based on politics, influence, or other reasons. These exceptions or restrictions can mean profit or loss to the landowner or developer. A piece of land that you can build a data center on is worth about 80 times as much as land that can only be farmed, for example.

The future and fate of Prince William County will be determined to a large extent by the Rural Area Plan. The Rural area is about protecting our Occoquan watershed and our groundwater and surface water resources. The Occoquan watershed is the most urbanized watershed in the nation and increasingly is a challenge to protect. Development increases impervious surface area, increases runoff and increases pollution and reduces groundwater recharge. This negatively impacts the drinking water supply for approximately 1.2 million Northern Virginians not just Prince William County. The downzoned portion of the Watershed within Fairfax and the Rural area have served as a natural water treatment system and high quality ecological habitat.

The comprehensive plan that is adopted needs to support the needs and values of our community today and tomorrow. 

Wednesday, May 26, 2021

The Spotted Lanternfly has arrived in Prince William County


The latest invasive bug to arrive on the scene in Virginia is the spotted lanternfly, which is not a fly, but an aphid. This bug was first detected in Virginia in January 2018 and now has been confirmed in Prince William County. This pest destroys grapes, peaches, hops and apples.

The spotted lanternfly is native to China and is present in several Asian Countries.  In 2014 it was found in Pennsylvania where it has spread to 26 counties and to Virginia. The first counties to be infested were Clark and Frederick. Though the Virginia Department of Agriculture and Consumer Services (VDACS) established a Spotted Lanternfly Quarantine for Frederick County and the city of Winchester to try and slow the spread of the spotted lanternfly to uninfected areas of the Commonwealth, it has arrived in Prince William County.

Spotted Lanternfly will lay egg masses on trees, but can also lay them on almost any other surface such as bricks, stone, lawn equipment, vehicles, and wood. The preferred tree species for Spotted Lanternfly as an adult and late stage nymph is "tree of heaven", Ailanthus altissima.  Tree of heaven is a non-native invasive tree that can be found throughout Prince William County.  It is often in disturbed habitats, particularly along wood edges and is often confused with similar looking natives. The long narrow leaves arranged in pairs across the plant’s stem do look like the black walnut; however, the reddish-brown twigs make it stand out. The tree of heaven is also known by a number of other names including stinking sumac, Chinese sumac, varnish tree and stink tree, the plant releases a strong, offensive smell, particularly from its flowers.  .  

Spotted Lanternfly nymphs and adults can be seen crawling up and down trees and will also congregate together in large groups to feed.  SLF feeds on sap.  Feeding can lead to oozing sap visible on the surface of trees and dark mold or fungi growing beneath the feeding area which can attract other insects. In late fall, Spotted Lanternfly adults will lay egg masses on host trees and nearby smooth surfaces like stone, outdoor furniture, vehicles, and structures. Keep your vehicles garaged (if you can)  to prevent the infestation from hitching a ride on your vehicle and infesting other parts of Virginia. 

You can help stop the spotted lanternfly in Virginia by making sure you don’t carry it to other locations and helping Virginia Cooperative Extension track its spread. Look for the distinctive bug to help. If you want to report a possible Spotted Lanternfly, snap a picture and go to Ask Extension:

The pictures below are from Viginia Tech as is the video above.

Sunday, May 23, 2021

Why is my Septic System Alarming?

You hear a muffled buzzing sound and finally step outside and realize your septic system is alarming. Many modern and alternative septic systems have alarms to notify the homeowner of a potential problem. In some locations like Prince William County the system also alarms in the house. So, what does it mean if an alarm sounds and what should you do? First of all, don’t panic.

There are a series of straightforward steps to take.

  • Silence the alarm so you can think and you do not annoy the neighbors. There is considerable variation in septic systems and alarms. There should be a toggle switch on the outside of the control box. Flick it to the off or silent position. Here in Prince William County, we also have an alarms in the basement. You will have to silence that one too.
  • Determine what type of alarm it is. Typically, it is either a high-water alarm or if you have a blower for an ATU tank the blower may be out.
  • If you have a blower, feel the casing of the blower motor to make sure that the blower is operating. You can also often hear the hum of the blower. If not, call a licensed and certified septic repair company (not a septic pump out company) to replace the blower. You have a day or two before the undertreated sewage starts flowing to your leach field and begins to damage it. Get it fixed before that happens.
  • If it is not the blower, then the alarm was probably a high water level alarm in your septic tank or your secondary tank.

A high water alarm is caused by either too much water going into the tank or not enough going out. A high water alarm if not properly addressed will cause septic waste to ultimately back up into your house, though that may occur after your drainfield is fully damaged. A typical septic system has four main components: a pipe from the home, a septic tank (or two), a drainfield (alternative systems might have drip fields, sand mounds or peat tanks where a traditional drainfield is not possible or has failed), and the soil. Many systems also have pumps to move the liquids from the home to the septic tank or from the septic tank to the drainfield, and all systems have pipes connecting the tanks and drainfield. There are also Alternative systems that have additional components such as; float switches, pumps, and other electrical or mechanical components including additional treatment tanks and filters which can clog if not cleaned and replaced regularly (depending on what you flush down the toilet or pour down the drain). It is the alternative systems and systems with pumps that typically have alarms.

A high water alarm is caused by one of two things:

  1. Too much water flowing into the septic tank or
  2. Not enough water flowing out.

If too much water is flowing in you either have a plumbing leak or a running toilet. After several years, the flapper in the toilet tank should be replaced because it does not always seal properly. Check every toilet (and tank) as well as all sinks for dripping faucets. Usually, it takes something like an incompletely closed faucet or running toilet and many hours to cause a septic tank to over fill. According to the U.S. Environmental Protection Agency, one out of every 10 homes has a leak that is wasting at least 90 gallons of water per day, look carefully for leaks.

The high water alarm is not likely to be caused by excess sludge in the waste tank, but it can happen when the tank has not been pumped for years and you have a couple of days of high volume usage or doing a month’s worth of laundry in a single day. That is what typically causes the septic system to backup during holidays and parties. A broken septic tank lid or cracked tank can also allow rain and runoff to enter the septic tank and over fill the tank. If it has not rained recently, or you were not running the hoses or a sprinkler, then that is unlikely to be the cause of a high water alarm.

If the problem is not the water entering the tank, then there is a problem with water leaving the tank. This could be caused by pump failure, a blockage in the line to the drainfield which may include a clogged filter, or clog in the drainfield itself. You need a septic service company to determine what is causing the problem, though check your circuit breakers to make sure that any pumps have power and you could pull the filter in the white pipe between your tanks and clean it out.

The basic design of a septic tank will only work if the sludge is not too thick on the bottom and the grease and scum is not too thick on top, and if the flow to the tank is not excessive. If there is too much waste on the bottom of the tank or too much water flowing to the tank, there will not be enough time for the solids and liquids to settle out before the tank starts releasing water containing large amounts of fecal waste to the drain field. The fecal waste will over time clogs the drainfield. Also, if there is too much grease and scum floating on top, the scum will be released to the drainfield. A septic system is not a trash can. Don’t put dental floss, feminine hygiene products, condoms, diapers, cotton swabs, cigarette butts, coffee grounds, cat litter, paper towels, latex paint, pesticides, or other hazardous chemicals into your system they can end up clogging the filter and/or lines if carried from the tank.

In addition, the National Small Flows Clearinghouse has seen septic distribution pipes plugged with a “noxious fibrous mass” that was grease and cellulose from toilet paper that only occurred in homes with water softening systems. A clog in the distribution system will also cause a high water alarm as the septic water cannot be released or pumped to the drainfield. It is believed that the brine in the conventional septic tank interferes with the digestion of the cellulose fibers and can be carried over into the septic systems drain field. A study in Virginia involving two adjacent septic field dispersal systems in a shared mound have shown that the trenches that received the septic effluent with water softener brine discharges formed a thick, gelatinous slime layer that clogged the infiltrating surface, while the trenches receiving no salt water discharge remained open with a normal microbial clogging layer. Commercial septic tank additives may assist in the breakdown of fecal waste, but do not eliminate the need for periodic pumping and can be harmful to the system. Saving money by not pumping your septic tank could result in the need to replace your drainfield.

Septic tank wastewater after preliminary settling and in alternative septic systems undergoing secondary treatment flows to the drainfield, where it percolates into the soil, which provides final treatment by removing harmful bacteria, viruses, and nutrients. The waste cannot contain too much solid material or scum. High quantities of solids in the waste stream will overwhelm the drainfield. Initially, nitrogen and fecal bacteria will be released to the groundwater as the soil becomes saturated with solids and scum. Eventually the perforations in the pipes to the leach field through which wastewater flows become clogged and the waste backs through the system. If a high-water problem is left unaddressed, the septic system will eventually back up into your home. Before the septic backs up into your home the high-water alarm will sound, attend to it.

This is an update and reprint of an older article.

Wednesday, May 19, 2021

My Water Well Results 2021

After the data transposition was corrected, the findings of my water analysis can be seen below. None of the chemicals or bacteriological indicators tested for exceeded U.S. EPA SDA recommended levels. This was a happy, but not unexpected result since this was the 15th  year in a row I have tested my water. However, when I first received my results the findings for fluoride and nitrate had been transposed. Since neither of those items should have had a sudden change of that magnitude in this geology. I did not believe it and contacted the Program Coordinator, Erin Ling, at the Virginia Household Water Quality Program, Biological Systems Engineering Department at Virginia Tech to investigate and verify. The transposition error was found and my report and 62 others were corrected.  

I test my drinking water at least once every year.  In the first few years that I owned this well I tested for all the primary and secondary contaminants in SDW act as well as a suite of pesticides using a certified laboratory. When we bought our home I tested the well using a certified laboratory and having the laboratory personnel draw the samples. I wanted data I could later use in court if I ever had to. For the certified data completed on a rush basis I ended up spending  a lot of money because I could only negotiate a 10 day contingency period and had to pay a huge premium for that rush. Still, I did not test for everything, nobody could afford to (I think there are 80,000 or more known chemicals).

Why was testing the water so important to me, that it was our one contingency. I wanted to make sure that the well was drawing from a groundwater aquifer that was not contaminated. While you can treat, you cannot really "fix" groundwater.  In addition, I wanted a well that was fine without any need for water treatment to address naturally occurring contaminants. I ended up testing for all the contaminants in the Safe Drinking Water Act and for a group of common pesticides because the home was on the site of a former farm.   

I tested for 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, TDS, alkalinity; 4 Trihalomethanes (THMs) and 47 Volatile Organic Chemicals (VOCs) including Benzene, Methyl Tert-Butyl Ether (MTBE) and Trichloroethene (TCE). Organochlorine pesticides, herbicides and PCBs. 

There was no treatment equipment in the house, so I was able to do only one set of water tests (thank goodness). Always test the raw water so that you know what you are buying, What you can live with in terms of water treatment equipment is really a personal decision. I preferred to have water that was not in need of any treatment and was a little hard because I like the taste of hard water (and soft water is often associated with slightly acidic water). I was more willing to renovate the kitchen than treat the water. It took me 10 years to get around to renovating the kitchen, but that whole time I've remained happy with my water.


Sunday, May 16, 2021

The Wells of Prince William County 2021


Last week all 81 well owners who participated in the 2021 Prince William County Well Water Clinic received their results by email. After a little hiccup for a data transposition error (nitrate and floride were transposed). If you received a report make sure you are looking at the corrected report. Above you can see the summary of what was found in the 81 wells tested. What VA Tech tested for were 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. These are the most common contaminants that effect drinking water wells.

To determine if treatment is necessary, water test results should be compared to a standard. The standard used was the U.S.EPA Safe Drinking Water Act (SDW) limits. Though private wells do not fall under the regulatory authority of the U.S. Environmental Protection Agency (EPA) or the Safe Drinking Water Act, the SDW act has primary and secondary drinking water standards that we use for comparison. Primary standards are ones that can impact health and from the tested substances include coliform bacteria, E. coli bacteria, nitrate, lead, and arsenic. Secondary standards impact taste or the perceived quality of the water.

Just because your water appears clear does not mean it is safe to drink. The 2021 Prince William County water clinic found that 21% of the wells tested present for coliform bacteria. This is lower than previous years. Coliform bacteria are not a health threat itself; it is used to indicate other bacteria that may be present and identify that a well is not properly sealed from surface bacteria. The federal standard for coliform bacteria is zero, but the federal standard allows that up to 5% of samples can test positive for coliform during a month.

One of those wells tested positive for E coli. Fecal coliform and E. coli are bacteria whose presence indicates that the water is contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and those with compromised immune systems. However, people can drink water contaminated with fecal bacteria and not notice.

If your well is contaminated with coliform but not fecal coliform or E. coli, then you have a nuisance bacteria problem and the source may be infiltration from the surface from rain or snow melt. Typical causes are improperly sealed well cap, well repairs performed without disinfecting or adequately disinfecting the well, failed grouting or surface drainage to the well. Very low levels of coliform (1-5 MPN) may present during extremely wet periods.

If your well had coliform bacteria present you should shock chlorinate the well (according to the procedure from VA Tech), repack the soil around the well pipe to flow away from the well and replace the well cap. Then after at least two weeks and the next big rainstorm retest the well for coliform. If coliform bacteria is still present then a long-term treatment should be implemented: using UV light, ozonation, or chlorine for continuous disinfection. These systems can cost up to $2,000 installed.

If you have fecal coliform in the well or E. coli, your well is being impacted by human or animal waste and you are drinking dilute sewage. If there is not a nearby animal waste composting facility, then you are probably drinking water from a failed septic system- yours or your nearest neighbors or in some older areas a leaking sewer line. To solve this problem you need to fix or replace the septic system that is causing the contamination, replace the well or install a disinfection and micro filtration or reverse osmosis system. Disinfection while killing the bacteria does not kill Giardia or Cryptosporidium, two microscopic parasites that can be found in groundwater that has been impacted by surface water or sewage. Both parasites produce cysts that cause illness and sometimes death.

The failing septic systems can often be identified by using tracer dyes. While continuous disinfection will work to protect you from fecal bacteria and E. coli, be aware that if your well is being impacted by a septic system, then the well water might also have present traces of all the chemicals and substances that get poured down the drain. Long term treatment for disinfection, and micro-filtration should be implemented: using UV light, ozonation, or chlorine for continuous disinfection, carbon filtration, and anything that is used for drinking should be further treated with a reverse osmosis systems or micro membrane system that works by using pressure to force water through a semi-permeable membrane. Large quantities of wastewater are produced by reverse osmosis systems and need to bypass the septic system or they will overwhelm that system creating more groundwater problems. Reverse osmosis systems produce water very slowly, a pressurized storage tank and special faucet needs to be installed so that water is available to meet the demand for drinking and cooking.

Nitrate can contaminate well water from fertilizer use; leaking from septic tanks, sewage and erosion of natural deposits. One of the wells in our group of 81 samples had nitrate levels above the MCL. The regulatory limit for nitrate in public drinking water supplies, 10 mg/L,  was set to protect against infant methemoglobinemia, but other health effects were not considered.

Dr. Mary Ward of the Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute has lead several important studies comparing all the research on the health impacts from exposure to nitrate in water. The first review was of studies published before 2005. In 2018 Dr. Ward was lead author on a review of more than 30 epidemiologic studies on drinking water nitrate and health outcomes.

This year they found 9% of homes had first draw lead levels above the SDWA maximum contaminant level of 0.015 Mg/L. After the flushing the tap for at least one minute no homes had lead levels above the 0.15 mg/L level; however, many scientists do not believe that any level of lead is safe to drink over an extended period of time. Often homes that have elevated lead in the first draw, have lower pH values.

Houses built before 1988 when the ban on lead went into effect and have low pH water typically have higher lead concentrations. Lead leaches into water primarily as a result of corrosion of plumbing and components in the well itself, but can also result from flaking of scale from brass fittings and well components. Corrosion control techniques such as adjusting pH or alkalinity that are commonly used to neutralize aggressive water will not work in to reduce lead being leached from well components. For most instances, though, a neutralizing filter and lead removing activated carbon filters can be used to remove lead leaching from plumbing pipes, solder and fixtures. Recently, some home water treatment companies are offering in home treatment systems that neutralize the water and add orthophosphate other phosphate solution to coat the piping to prevent further corrosion. It should work, but I have never seen such a home system and am not aware of any testing.

Iron and manganese are naturally occurring elements commonly found in groundwater in this part of the country. 9.9% of the wells tested exceed the iron standard and 7.4% exceeded the manganese standard. At naturally occurring levels iron and manganese do not present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing and discolored water. The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese can be detected by taste, smell or appearance. In addition, some types of bacteria react with soluble forms of iron and manganese and form persistent bacterial contamination in a well, water system and any treatment systems. These organisms change the iron and manganese from a soluble form into a less soluble form, thus causing precipitation and accumulation of black or reddish brown gelatinous material (slime). Masses of mucous, iron, and/or manganese can clog plumbing and water treatment equipment.

All systems of removing iron and manganese essentially involve oxidation of the soluble form or killing and removal of the iron bacteria. When the total combined iron and manganese concentration is less than 15 mg/l, an oxidizing filter is the recommended solution. An oxidizing filter supplies oxygen to convert ferrous iron into a solid form which can be filtered out of the water. Higher concentrations of iron and manganese can be treated with an aeration and filtration system. This system is not effective on water with iron/ manganese bacteria but is very effective on soluble iron and manganese so you need to do further testing to determine what type of iron/manganese you have before you install a treatment system. Water softeners can remove low levels of iron and are widely sold for this purpose because they are very profitable but are now being banned in some locations due to rising sodium and chloride levels.

Chemical oxidation can be used to remove high levels of dissolved or oxidized iron and manganese as well as treat the presence of iron/manganese (or even sulfur) bacteria. The system consists of a small pump that puts an oxidizing agent into the water before the pressure tank. The water will need about 20 minutes for oxidation to take place so treating before a holding tank or pressure tank is a must. After the solid particles have formed the water is filtered. The best oxidizing agents are chlorine or hydrogen peroxide. If chlorine is used, an activated carbon filter is often used to finish the water and remove the chlorine taste. The holding tank or pressure tank will have to be cleaned regularly to remove any settled particles.

The pH of water is a measure of the acidity or alkalinity. The pH is a logarithmic scale from 0 – 14 with 1 being very acidic and 14 very alkaline. Drinking water should be between 6.5 and 8.5. For reference and to put this into perspective, coffee has a pH of around 5 and salt water has a pH of around 9. Corrosive water, sometimes also called aggressive water is typically water with a low pH. (Alkaline water can also be corrosive.) Low pH water can corrode metal plumbing fixtures causing lead and copper to leach into the water and causing pitting and leaks in the plumbing system. The presence of lead or copper in water is most commonly leaching from the plumbing system or well rather than the groundwater. Acidic water is easily treated using an acid neutralizing filter. Typically these neutralizing filters use a granular marble, calcium carbonate or lime. If the water is very acidic a mixing tank using soda ash, sodium carbonate or sodium hydroxide can be used. The acid neutralizing filters will increase the hardness of the water because of the addition of calcium carbonate. 16% of the wells tested were found to have acidic water this year.

Water that contains high levels of dissolved minerals is commonly referred to as hard. Groundwater very slowly wears away at the rocks and minerals picking up small amounts of calcium and magnesium ions. Water containing approximately 125 mg/L can begin to have a noticeable impact and is considered hard. Concentrations above 180 mg/L are considered very hard. Hard water can be just a minor annoyance with spotting and the buildup of lime scale, but once water reaches the very hard level 180 mg/L or 10.5 grains per gallon, it can become problematic. Overall 7.4% of homes tested had hard water.

Two methods are commercially available (and certified) to treat hard water. A water softener and a water that work through a process called template assisted crystallization (TAC), have been certified by DVGW-W512 and are available in whole house units. In template assisted crystallization, water flows through a tank of TAC media. When the hard water comes into contact with the media, the magnesium and calcium ions are caught by the nucleation sites. As more calcium and magnesium ions build up within the sites, small micro-crystals form and flow through your plumbing. They do not attach themselves to your water pipes as scale.

The ubiquitous water softening system is an ion exchange system consisting of a mineral tank and a brine tank. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions (along with small amounts of other minerals) are positively charged and are attracted to the negatively charged beads. This attraction makes the minerals stick to the beads as the hard water passes through the mineral tank. Sodium from salt is used to charge the resin beads. The brine tank is flushed out when the resin beads are recharged carrying the salty solution to the environment. The salinity of surface waters and groundwater is an emerging environmental concern. Research has shown that salinization has affected over a third of the drainage area of the contiguous United States even in areas without road salt. At the present time the EPA guidance level for sodium in drinking water is 20 mg/L. Given the number of homes with elevated sodium and our local geology, it is probably a reflection of the number of homes with water softeners-50.6% of the wells tested had elevated sodium.

1.2% of wells were found that had arsenic exceeding the EPA MCL for drinking water of 10 ppm. While arsenic is a naturally occurring element found in soil and groundwater it is not typically found at significantly elevated levels in this geology. Arsenic is best removed by water treatment methods such as reverse osmosis, ultra-filtration, distillation, or as a last choice ion exchange (water softeners). Typically, these methods are used to treat water at only one faucet. Though anionic exchange systems (water softeners) are whole house systems, they may not be the best choice.

Wednesday, May 12, 2021

The New Climate Normals

Every decade the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information updates the “Climate Normals.” The U.S. “Climate Normals” are the collection of data that provide information about typical climate conditions for thousands of locations across the United States. Normals act both as a ruler to compare today’s weather and tomorrow’s forecast, and as a predictor of conditions in the near future. The official Normals are calculated for a uniform 30 year period across the United States and the world, and consist of annual/seasonal, monthly, daily, and hourly averages and statistics of temperature, precipitation, and other climatological variables from almost 15,000 U.S. weather stations. 

The official U.S. Normals are recalculated every 10 years in keeping with the requirements of the World Meteorological Organization (WMO) and National Weather Service (NWS), and this has just been completed. The 1991–2020 U.S. Climate Normals are the latest in a series of decadal Normals first produced in the 1950s. These data allow travelers to pack the right clothes, farmers to plant the best crop varieties, and utilities to plan for seasonal energy usage as well as allow water utilities for forecast supply.  Many other important economic decisions that are made beyond the predictive range of standard weather forecasts are either based on or influenced by climate Normals.

NOAA has just released the updated set of climate “Normals.” These new normals include things like average highs, average lows, average temperature, average precipitation, and average snowfall for 15,000 locations in in the United States. The normal cover a 30 year period overlapping with the data from the previous set released in 2010. This way the new set of climate normals  evolves slowly and smoothly over time and keeps a good baseline for the climate, which will continue to change over time. 

NOAA’s normals give weather forecasters, businesses and us a way to compare today’s conditions to 30-year averages. Temperature and precipitation averages and statistics are calculated every decade so we can put today’s weather into proper context and make better climate-related decisions. Two maps below show the changes in the normals from the last data group.

Temperatures change very slowly, but there seems a larger change in precipitation. The data shows that changes over the past decade and input into the series have seen an uneven change.  Even in Prince William County the change has been uneven. As you can see in the detail below, the eastern portion of the county has gotten warmer than the western portion and the precipitation has seemingly increased only in the western portion of the county. The 1991–2020 U.S. Climate Normals are the latest in a series of decadal normals first produced in the 1950s. These data allow travelers to pack the right clothes, farmers to plant the best crop varieties, and utilities to plan for seasonal energy usage. Many other important economic decisions that are made beyond the predictive range of standard weather forecasts are either based on or influenced by climate normals.

Detail from NOAA map

Detail from the NOAA map above

The U.S. Climate Normals are a large suite of data products that provide information about typical climate conditions for thousands of locations across the United States. Normals act both as a ruler to compare today’s weather and tomorrow’s forecast, and as a predictor of conditions in the near future. The official normals are calculated for a uniform 30 year period, and consist of annual/seasonal, monthly, daily, and hourly averages and statistics of temperature, precipitation, and other climatological variables from almost 15,000 U.S. weather stations. 

U.S. Climate Normals are designed—and best-suited for—better understanding what is happening today. Rather than assess long-term climate trends, Normals reflect the impacts of the changing climate on our day-to-day weather experience. Normals are thirty years of U.S. weather station observations are compiled, checked for quality, compared to surrounding stations, filled in for missing periods, and used to calculate not only averages, but many other measures. These then provide a basis for comparisons of temperature, precipitation, and other variables to today’s observations.

Below are the monthly normals for Manassas, VA. The weather we are likely to see. An interesting note is the increase in precipitation over the period.


Locally, in the western portion of the county the weather has gotten a little wetter and about half a degree warmer. The data for the drought in the 1980’s was deleted and replaced with the recent wet years. So the average rainfall has increased to more than 47 inches per year. The variation in temperature is much less pronounced.


Sunday, May 9, 2021

The Plan for Conowingo Pollution Releases

The Conowingo Dam is a large hydroelectric dam on the Lower Susquehanna River about 10 miles upstream from where the river flows into the Chesapeake Bay at Havre De Grace, Maryland. The three dams at the downstream end of the Susquehanna River have been important in mitigating the downstream transport of nitrogen, phosphorus, and suspended sediment from the Susquehanna River watershed to the Chesapeake Bay. The Conowingo, the last dam in a series of three traps polluted sediment from the Susquehanna River in its 9,000 acre reservoir.

When the Chesapeake Bay Total Maximum Daily Load (Bay TMDL) was established in 2010, it was estimated that the reservoir behind the Conowingo Dam would trap sediment and associated nutrients through 2025. However, studies conducted over the last several years demonstrated that the reservoir has reached dynamic equilibrium (i.e., the reservoir is near full capacity).

The Conowingo Dam will no longer be able to trap sediment in the Susquehanna River and prevent them from entering the Chesapeake Bay. The Susquehanna River flows 464 miles from Cooperstown, New York to Havre De Grace, Maryland collecting sediment and nutrient runoff along the way. The Susquehanna drains an area of more than 27,000 square miles and is the single largest source of fresh water flowing into Chesapeake Bay. The river currently provides nearly half of the Bay’s freshwater, 41% of its nitrogen, 25% of its phosphorus and 27% of its sediment load. Without the Conowingo removing sediments containing nitrogen and phosphorus the reductions in sediment, nitrogen and phosphorus will have to come from somewhere else.

The Chesapeake Bay Program’s has developed a separate Conowingo Watershed Implementation Plan (WIP) that outlines the programmatic and numeric commitments that need to be taken to reduce the adverse water quality impacts to the Chesapeake Bay resulting from Conowingo Dam infill, as well as a timeline at which those reductions could be achieved. The Conowingo WIP strategy primarily focuses on the even more implementation of agricultural BMPs to reduce 6 million pounds of nitrogen in the Susquehanna River Basin.

A draft Watershed Implementation Plan (WIP) was developed by a committee consisting of representatives from the Chesapeake Bay Commission and each Chesapeake Bay watershed jurisdiction – Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia – and supported by the Center for Watershed Protection to assign the additional reduction of 6 million pounds of nitrogen and 0.26 million pounds of phosphorus needed to mitigate the water quality impacts of Conowingo Dam infill.

EPA states in their news release that it “recognizes that the Conowingo WIP will continue to evolve based on implementation successes and challenges,” but noted that “critical to the successful implementation of the Conowingo WIP is to ensure that the plan complements and does not compete with the jurisdictions’ Phase III WIPs in terms of opportunities for BMP implementation and resources, including technical assistance, staffing, and funding.”  The evaluation states that “it is currently unclear” how the two efforts will be distinguished and recommends that the final CWIP “provide more detail on where exactly implementation will be targeted and the affected stakeholders.”

The EPA evaluation also recognizes that the Conowingo WIP financing strategy is still under development, but notes “there is currently little confidence that the Conowingo WIP will be fully implemented to meet the necessary nitrogen reductions without dedicated funding mechanisms in place and the commitment from the public sector to provide an initial investment to initiate Conowingo WIP implementation.”

Unlike the individual state WIP III,  EPA does not approve or disapprove the Conowingo WIP. However,  EPA does provide its evaluation and provide recommendations for strengthening the Conowingo WIP. The EPA has completed its evaluation of the draft Conowingo WIP to mitigate and additional 6 million pounds of Chesapeake Bay pollutants no longer being trapped in a reservoir behind the Conowingo Dam. The EPA has expressed concerns that there is no way to distinguish Conowingo WIP restoration actions from others already pledged, as well as the need for a dedicated funding mechanisms and public sector financial commitments for the additional work.

Let’s be honest here. Implementation of Agricultural BMPs in the Susquehanna River Basin has lagged even without these additional goals, and climate projections for our region forecast that on average, precipitation in the region  is projected to increase by around 8% by 2040, and temperature is projected to increase by 2.16 °C (3.9 °F). “Because warmer air can hold more moisture, heavy rainfall events ...are projected to increase in frequency and severity as the world continues to warm. Both the intensity and rainfall rates of Atlantic hurricanes are projected to increase with the strongest storms getting stronger in a warming climate. Recent research has shown how global warming can alter atmospheric circulation and weather patterns such as the jet stream, affecting the location, frequency, and duration of these and other extremes,”  says the Fourth National Climate Assessment.

The bottom line here is no matter what mankind does, in the next couple of decades the expected impacts from climate change are going to happen. At this point, Human's actions can only have impact  on the second half of the 21st century. The Conowingo Dam cannot be left full. It will not exist in some gentle equilibrium. The Conowingo and its sister reservoirs will not be constantly filled to capacity with sediments because of short-term changes from severe storms that cause scour and a subsequent reduction in exported sediments until the scoured amount is refilled. Therefore, the amount of sediment transported out of the reservoirs will not always be in equilibrium with the amount of sediment transported into the reservoirs. Dredge it. Just put the bill into one of the multitrillion dollar spending plans. The senators from Virginia, Maryland, New York, and Delaware could simply come together to require the inclusion of the restoration of the Conowingo Dam in one of the bills. Long term capital improvements are the sorts of things that should be financed.

See Also: Hirsch, R.M., 2012, Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality: U.S. Geological Survey Scientific Investigations Report 2012–5185, 17 p.

Wednesday, May 5, 2021

Powell's Creek Restoration


from Prince William County

The Prince William County Department of Public Works has just begun a project to restore a portion of Powell Creek. This project is the largest project Public Works has taken on, and will include clearing along the creek, temporarily rerouting Powell's Creek, removing existing sediment, channel relocation to restore the streambed, stream bank reinforcement and replanting with native plants and trees to finish the project and connect this section of Powell's Creek with its wetland system.

All the improvements will create a meandering creek with riffles, where water runs swiftly over rocks to introduce oxygen into the water, along with pools to bring equilibrium to the stream to control sediment. Once established, the new trees and native plants will stabilize the stream bank at the same time they provide shade and reduce algal growth. "Even though you're impacting the wetlands temporarily, they're going to be improved ... because we're reconnecting to the flood plain," said Prince William County Environmental Engineer Tom Dombrowski. "What we're trying to do is restore it to what it was, which is wetland forest. We're changing it to be what it was, the way nature intended it to be," said Tom Dombrowski.

The project will encompass nearly one-mile along part of Powell's Creek, just off Cardinal Drive and Merrily Way, behind the Montclair and Four Seasons subdivisions. The two-year project will establish wetlands along the boundaries of Powell's Creek to act as buffers against flooding. According to Tom Dombrowski "It is actually going to store the water in the wetlands that are on the flood plain and prevent any major flooding downstream ...”  

The Powell's Creek project will also improve degraded bank conditions that threaten a sanitary sewer main transmission line and reduce sediment and nutrient runoff to meet the U.S. Environmental Protection Agency (EPA) mandated reduction in these pollutants. The Chesapeake Bay and its tidal waters are impaired by  the release of excess nitrogen, phosphorus and sediment. These pollutants cause algae blooms that consume oxygen and create dead zones where fish and shellfish cannot survive, block sunlight that is needed for underwater grasses, and smother aquatic life on the bottom. The US EPA has taken control of the situation and has developed a federally mandated total maximum daily limit, TMDL, to restore the Chesapeake. 

The TMDL allocates a pollution budget among the states and localities including Prince William County that limit the daily amount of sediment, nutrients and other pollution going into their waterways. Deforestation decades ago, and ongoing development, continue to impact streams and make restoration necessary. If it's out of whack, it's because of how we developed the land around it. Stream restoration is one of the better ways to solve the problem," Dombrowski said.

While the primary goals of stream restoration are to protect infrastructure, clean up the watershed and protect property, completed projects create environments for a wide range of water-dwelling macro-invertebrates, fish, birds and mammals. Residents will be able to enjoy walking around the restorations. Once fully established, the riparian zone, or areas surrounding the stream, will not only protect the stream bank from erosion, but also take up nutrients before the nutrients can enter Powell's Creek, which runs to the Potomac River, which in turn, flows to the Chesapeake Bay. "By making these changes, we're achieving a goal of preventing pollution from going into the Chesapeake Bay. These goals are multi-faceted" said Prince William County Environmental Engineer Tom Dombrowski.

Sunday, May 2, 2021

Groundwater Wells are Drying Up

The  April 23, 2021 issue of Science Magazine showed up in my mailbox over the weekend. I was excited to see that the mainstream of science has finally recognized the importance and the building crisis in groundwater! The cover  (as clipped below) was a picture of an agricultural water well in India and a barren and dry land. The title of the issue was “DRY WELLS” with a subtitle “Falling groundwater levels threaten wells globally.” There are two articles in this issue addressing the building groundwater crisis and both are very worthwhile reading -free access is available through the public library. 

“The hidden crisis beneath our feet.” By James S.Famiglietti and Grant Ferguson; Science 23 April 2020; pages 344-345.

“Global groundwater wells at risk of running dry.” By ScottJasechko and Debra Perrone; Science 23 April 2021; pages 418-421.

I have been following the work of Dr. Famiglietti’s since his NASA days. Dr.  Famiglietti is a hydrologist and Executive Director of the Global Institute for Water Security at the University of Saskatchewan. He holds the Canada 150 Research Chair in Hydrology and Remote Sensing. Before moving to Canada, Dr. Famiglietti served for four years as Senior Water Scientist at NASA’s Jet Propulsion Laboratory at the California Institute of Technology. Before that he was on the faculties of the University of California, Irvine and the University of Texas at Austin where he and Dr. Matt Rodell developed the methods of using the GRACE satellite data to measure changes in groundwater storage.

Rodell, M., and J. S. Famiglietti. 2002. "The potential for satellite-based monitoring of groundwater storage changes using GRACE: The High Plains aquifer, central U.S." J. Hydrology, 263: 245-256.

Below are quoted and paraphrased some of the key points made by Drs. Jay Famiglietti and Grant Ferguson and Drs. Scott Jasechko and Debra Perrone in last weeks Science Magazine.

Water is at the core of a sustainable earth and is critical not only for economic development and healthy ecosystems, but for human survival itself. Ninety-six percent of the earth’s non-frozen freshwater is groundwater, fresh water (from rain or melting ice and snow) that soaks into the soil and is stored in the tiny spaces between rocks and particles of soil. Groundwater is the primary water source for billions of people and nearly half of irrigated agriculture. Groundwater is also an essential component of the baseflow of our rivers, streams and creeks. Because groundwater is unseen, mankind has been using it unsustainably. More than half of the world’s major aquifers are being depleted. 

Using the well construction data for 39 million groundwater wells in 40 different countries along with available monitoring data Drs. Jasechko and Perrone found that from India to the United States groundwater wells are already running dry from groundwater level declines. Because they are only a few meters below the water table, from 6%-20% of groundwater wells are in danger of running dry from declining groundwater levels, seasonality and drawdown. Though, newer wells tend to be deeper than older wells, it provides only short-term reprieve from declining water levels and increases the cost to construct and operate a well. 

Groundwater depletion is projected to continue in the areas where it is already occurring and expand into new areas not yet experiencing depletion. Millions of wells are at risk of running dry. Despite this not all areas and countries are engaged in long term groundwater monitoring. Here in Prince William County, Virginia we do not have a groundwater monitoring program. There is an opportunity right now with the county awash in stimulus money to establish a groundwater monitoring network within the county to develop the relationship to land use, weather and water use to sustainable water.

As the authors point out, existing groundwater wells are vulnerable to groundwater depletion because many wells are not much deeper than the local water table, making them likely to run dry with even modest declines in groundwater levels. Maintaining the water level above the well pump intake is critical to sustainable water use but has been ignored in favor of recording recharge rates in our own well completion reports. Predicting changes to water level requires that measurements be taken and the hydraulic properties of the subsurface be studied.  Drs. Famiglietti and Ferguson point out to ensure that groundwater remains a reliable component of water supplies new networks must be fostered to raise awareness of the urgency of the situation and encourage and coordinate stakeholder participation and help our local and state governments build the political will to protect groundwater as a key element of water security and sustainability.