Thursday, May 31, 2018

WSSC to Eliminate Class B Biosolids

WSSC announced this month that their Commissioners have approved the first phase of a $250 million project that will transformation of WSSC current Class B Biosolids into Class A (pathogen-free) Biosolids material, recovering energy and reducing disposal costs along the way. The first phase is a $44 million contract that will allow WSSC to begin design and site preparation of the Piscataway Bio-Energy Project which will be located at the Piscataway Water Resource Recovery Facility (formerly the Piscataway waste water treatment plant) in Prince George’s County.

The Water Resource Recovery treatment process uses screens to remove large solids from wastewater, and performs some rudimentary treatment to remove crude solids of human waste and skim off grease, oil and fat. Wastewater sits in settling tanks where most of the heavy solids fall to the bottom of the tank, where they become thick slurry known as primary sludge.

The sludge is separated from the wastewater during the primary treatment is further screened and allowed to gravity thicken in a tank. Then the sludge is mixed with the solids collected from the secondary and denitrification units. The combined solids are pumped to tanks where they are heated to destroy pathogens and further reduce the volume of solids. With treatment sludge is transformed (at least in name) to Biosolids. Currently, WSSC treats their sewage Biosolids to only Class B at their 5 Water Resource Recovery Facilities (formerly waste water treatment plants). The problem, however, is how to dispose of the never ending supply of Biosolids.

To ensure that Biosolids applied to the land as fertilizer do not threaten public health, the EPA created the 40 CFR Part 503 Rule in 1989 that is still in effect today. It categorizes Biosolids as Class A or B, depending on the level of fecal coliform and salmonella bacteria in the material and restricts the use based on classification. The presence of other emerging contaminants in the Biosolids is not tracked. The land application of Class B Biosolids has been a growing area of concern. Research at the University of Virginia found that organic chemicals persist in the Class B Biosolids and can be introduced into the food chain. The new Biosolids treatment system will reduce the overall amount of Biosolids and improve their safety by producing only Class A Biosolids-free of pathogens.

WSSC says that this facility is the largest and most technically advanced project ever constructed by WSSC in its 100-year history.

“The Piscataway Bio-Energy Project will save our customers more than $3 million per year and underscores our commitment to green energy,” said WSSC General Manager and CEO Carla A. Reid. “Through cutting-edge technology, we will be able to recover vital resources from the wastewater treatment process and reduce our greenhouse gas emissions.”

In the future, the Biosolids (sludge) will be screened and dewatered at each plant then hauled from the four treatment plants to the Piscataway plant. The new plant will have thermal hydrolysis trains, digesters, dewatering equipment and a combined heat and power plant at a cost now estimated to be $250 million. The new digester system will use thermal hydrolysis (heating to over 160 degrees under high pressure) followed by anaerobic digesters. The system will produce methane gas which will be captured and used to run turbines to produce power that will meet Piscataway’s electric demand and the digestion process is projected to destroy nearly one half of the total Biosolids and produce Class A Biosolids reducing the chemical treatment costs and the transportation costs to get rid of the Biosolids. This is projected to save WSSC $3 million a year. Even with all these savings the project has a payback of over 83 years, so this was not about savings, but rather better sewage treatment, tighter EPA regulation for disposal of Class B Biosolids and meeting the Chesapeake Bay TMDL. Class A Biosolids are safer and easier to use in agriculture.

As an added benefit, the process to create the Class A Biosolids will generate renewable fuel to help run the plant. This new process produces methane gas, which will be captured to provide the Piscataway facility with a reliable power source that is completely off the grid. The new process will reduce WSSC’s greenhouse gas emissions by 15%.

The $44 million contract for the first phase of the project was awarded to PC Construction Company. The first Phase of work includes design and demolition of existing on-site facilities and relocation of existing utilities. Phase Two is expected to be awarded fall 2019. The entire project should be complete and operational in spring 2024.

Monday, May 28, 2018

Coliform “PRESENT”- How to Fix it

This spring in the well water clinic we run each year we found 25 wells out of 114 that had coliform "PRESENT." On a state level, the occurrence of coliform is higher. Of the approximately 7,000 households that participated in the Virginia Household Water Quality Program clinics from 2007 to 2015  they found that 41% of the wells had coliform bacteria, and 9% had E. coli bacteria. Though the 7,000 households may not be representative of all private drinking water wells in Virginia, it is the largest database on private drinking water wells available. It is safe to say that coliform contamination is widespread. 

If your water is contaminated with coliform but not fecal coliform or E. coli, don't panic. 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 the well, failed grouting or surface drainage to the well. If your well had coliform bacteria present you should shock chlorinate the well, 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 your well test PRESENT for coliform standard protocol is:
  1. Carefully check the well and water system for points of contamination. Make sure you have a sound and secured sanitary well cap and that the soil around the well is packed to drain water away from the well. 
  2. Then treat the well and plumbing system with chlorine for 12-24 hours to disinfect system (the 12-24 hours is essential). Then flush the chlorine from the system- not to your septic system. Make sure that this is done correctly
  3. Retest the water after the chlorine has left the system in about 10 days to two weeks. If coliform bacteria is “ABSENT” you’re done. If not, then it is time to install a long term disinfection system. (UV light or continuous chlorination)

In an existing well system that formerly was bacteria free look for these defects:
  • A missing or defective well cap and check seals around wires, pipes, and where the cap meets the casing may be cracked, letting in contaminants. 
  • Contaminant seepage through the well casing - cracks or holes in the well casing allow water that has not been filtered through the soil to enter the well. This seepage is common in the wells made of concrete, clay tile, or brick. This can also happen to a steel pipe well that was hit by a piece of equipment such as a car, snow blower, lawn tractor or mower or that has rusted. 
  • Contaminant seeping along the outside of the well casing - many older wells were not sealed with grout when they were constructed or the grouting has failed. Check the grouting carefully especially if water seems different after severe rains. 
  • Well flooding - a common problem for wellheads located below the ground in frost pits that frequently flood during wet weather. 
Coliform bacteria are commonly found in soil, on vegetation, and in surface water. Some coliform bacteria strains can survive in soil and water for long periods of time. Coliform bacteria will not likely cause illness. Coliform bacteria do not occur naturally in most aquifers. Fractured or creviced bedrock aquifers that are close to the surface are the exception. Be aware that there are three different groups of coliform bacteria; total coliform, fecal coliform and Escherichia coli (E. coli) each has a different level of risk. If your water is contaminated with coliform but not fecal coliform or E. coli, then you have a nuisance bacteria problem.

Bacteria washed into the ground by rainfall or snowmelt are usually filtered out as water seeps through the soil, so properly constructed water wells do not typically harbor Coliform bacteria. However, coliform bacteria can persist within slime formed by naturally occurring ground water microorganisms. The slime (or biofilm) clings to the well screen, casing, drop pipe, and pump and may even invade filter systems. Disturbances during pumping or well maintenance can cause the slime to dislodge, releasing the coliform bacteria.

Keep in mind that coliform bacteria do not always show up in every sample. They can be sporadic and sometimes seasonal when they occur in a water supply. You should not continue drinking water contaminated with coliform, either boil the water drink bottled water until you disinfect your well. Bring the water to a rolling boil for one to five minutes (the higher the elevation the more time is necessary) to kill the bacteria. You may also want to consider using bottled water as a temporary drinking and cooking water source.

You may have received a total coliform count. This gives you a general indication of the sanitary condition of a water supply and extent of the problem. Bacteria can be introduced into a new well during construction and can remain if the water system is not thoroughly disinfected and flushed. Well construction defects such as insufficient well casing depth, improper sealing of the space between the well casing and the borehole, corroded or cracked well casings, and poor well seals or caps can allow surface water or insects to carry coliform bacteria into the well. These problems are common and the most likely source of the coliform bacteria contamination. Unplugged abandoned wells can also carry coliform bacteria into deeper aquifers.

Since bacterial contamination cannot be detected by taste, smell, or sight, all drinking water wells should be tested at least annually for Coliform bacteria.

a sanitary well cap

typical drilled well

Thursday, May 24, 2018

Reduce first then Reuse and finally Recycle

I was at the University of Virginia graduation last weekend. As we walked up to the lawn a gentleman offered us water bottles. It was humid and hot and my husband and I took one and said we would share. As I looked around waiting for the diploma ceremony to begin I thought about all those water bottles. There we recycle bins everywhere I looked, but the truth is that recycling encourages single use products like water bottles, straws, disposable plates etc. Recycling is only beneficial only if it reduces the production of virgin plastic from oil, not if it encourages more single use products. It is reported in New Scientist that 50% of PET plastic is collected for recycling, but only about 7% is turned into new bottles. Why, it is cheaper to make new plastic.

Since the beginning of the 20th century mankind has made an estimated 8,300 million metric tons of plastic. Around 6,200 million metric tons has been thrown away and almost 5,000 million metric tons of plastic pollutes the environments (our oceans, river and streams, estuaries, along roadways etc.) or dumped into landfills. This is an environmental catastrophe on a global scale in the making. Already there are areas in the developing world where people live ankle deep in plastic trash and filth.

The biggest challenge to solving the plastic pollution problem is human behavior. The best approach is to reduce your consumption of plastic. If we do nothing, much of the world will be knee deep in plastic in a generation. We must reduce plastic waste. Here are the 5 things you can do to reduce plastic waste:
  1. Eliminate single-use plastic- water bottles, straws, disposal plates. However, think what you substitute. A steel water bottle needs to be used 500 times for its carbon footprint to shrink below the carbon footprint of a single use PET plastic bottle. A permanent plastic bottle is a better substitute.
  2. Reduce Packaging you buy. By buying large containers and avoiding single serve containers. Use bar soap instead of a pump bottle.
  3. Buy your Products in concentrated form. Buy your detergents and soaps in concentrated form, less packaging and less weight to ship. You can dilute it at home.
  4. Do not buy any products with mixed material packaging. These materials cannot be recycled. These include the food pouches especially popular in baby food and bags used for chips, pretzels and the like. Also, avoid using those black plastic food containers which are not easily sorted by the infrared sorting lights in recycling plants and are often simply trashed.
  5. Finally, consider consuming less packaged food, and fewer plastic items. Reduce.

Monday, May 21, 2018

Microplastics in Our Environment

The ubiquitous use of plastic in our modern world and inadequate management of plastic waste has led to increased contamination of freshwater, estuary and marine environments. The U.N. Food and Agriculture Organization (FAO) estimated that in between 4.8 million to 12.7 million metric tons (tonnes) of plastic waste each year.  Research on pollution from small plastic particles less than 5 millimeters in size, called micro plastics, has long focused on ocean pollution where most of the plastic residue ends up. Over the past 14 years, researchers have documented and studied microplastics contamination of earth’s oceans. Tremendous advances have been made in understanding the sources, fate and impact of microplastics and their associated chemical in the oceans and marine environment.

However, recently, scientists have begun to study the microplastics in freshwater and land. It was first reported that microplastics were found in freshwater lakes in 2013. Though oceans represent the largest sink of persistent plastic waste, an estimated 80% of the microplastics pollution in the oceans comes from the land. The plastics flow to the oceans and lakes from our rivers. Microplastics contamination as seen in marine animals has also been found in freshwater organisms.

Though scientists expect the effects of microplastics on freshwater organisms to be similar to those observed on marine organisms, the research has just begun. Microplastics end up in the soil environment from sewage sludge that is widely applied to agricultural lands. Fibers from laundry end up in the sewage sludge and it is spread on the land. Other sources of microplastics are weathering and disintegration of plastic sheeting used in agriculture, the fragmentation of plastic litter and plastic items both litter and in landfills. 

So far the limited studies of microplastics in the freshwater and land environments suggest that microplastics contamination is as ubiquitous on land and in freshwater as in oceans. More research needs to be done, but it is very clear that plastics are responsible for a vast array of ills from poisoning and injuring marine life, disrupting animal and human hormones, littering beaches and landscapes and clogging our waste streams and landfills, the exponential growth of plastics is threatening our planet. It will take a multi-prong approach to reduce this threat.

Each year we hold the Potomac River Watershed Cleanup which is the largest regional event of its kind and happens over several weekends each spring. Year after year volunteers clean our roadways, streams, rivers, and streambeds of trash (most of it plastic) that started as litter and was carried along by stormwater and wind into our waterways and parks or items that were illegally dumped in the woods or carried by off by storms.

This year our annual Upper Occoquan River Cleanup took place over the April 21st  weekend and covered a ¼ mile of Broad Run, and a 25 mile stretch of the Occoquan River from below the Lake Jackson Dam past Riverview Estates, Occoquan Forest, Canon Bluff, Lake Ridge Marina and Hooes Run. There were 294 Volunteers  from these communities who collected 410 trash bags, 59 tires and 10-55 gallon barrels. Volunteers cleaned up debris on the water, land or assisted in moving the debris on shore to waiting trucks or dumpsters. In all they removed 10,600 pounds of trash, but more needs to be done. 

There are lots of opportunities for you to volunteer to help cleanup our streams. Contact the Prince William Soil and Water Conservation District. You can  join our programs or simply start with the most basic steps: Don’t litter and teach your children not to litter. Reduce your use of plastics. 

Eliminating litter is the best way to prevent trash along our roads, streams and waterways. The trash does not magically disappear, but finds its way carried by stormwater to our waterways and park lands disrupting the natural water flow and beauty of our natural world.

Also, reduce your use of plastics. Begin with reducing plastics that we use once and discard- like bottles of water. This is becoming a critical problem of global proportion. Plastics are some of the most commonly littered items in the world and they are drowning our planet. Plastics are present in furniture, construction materials, cars, appliances, electronics and countless other things. Be mindful of what you buy and how you use it. 

Thursday, May 17, 2018

New Homes in California Required to Have Solar Panels

Last week (May 9, 2018), the California Energy Commission voted unanimously to require solar panels on all new single-family homes and apartment buildings that are less than three stories tall. If confirmed by the California Building Standards Commission, which typically adopts the Energy Commission's recommendations when it updates the state's building codes the regulation will go into effect in 2020. The new regulations would require a solar system of a minimum 2 to 3 kilowatts, depending on the size of the home. A typical household in California consumes approximately 600 kilowatt-hours of electricity per month on average and this size system would produce about 400 kilowatt hours a month. So the homes subject to this mandate will continue to draw power from the electric grid.

The proposed regulations include exceptions to solar panel installation when solar panels are not feasible, such as when a home does not receive sufficient sunlight for electrical generation, and builders can construct a shared solar-power system serving a group of homes in lieu of providing solar panels on each residence.

In the news release the Energy Commission estimated the solar panel mandate will add $9,500 to the construction cost of an average single-family home, but the Energy Commission estimated that the solar panels will save homeowners approximately $19,000 in energy and other expenses over 30 years-less than a 2.5% return and less than the cost of financing the project as part of the mortgage. This will increase the purchase cost of a home in California, and further exacerbate California's significant housing shortage and affordability crisis. Currently, there are more than 5 million homes in California that use solar power for either electrical generation or to heat hot water. California is the nation's leader in the number of solar panel installations, but it is also the most populous southwestern state.

With solar panels included in the price of a new home, this simplifies financing of solar panels and allows homeowners to finance them as part of a mortgage. Homeowners could avoid the challenges that the California's Property Assessed Clean Energy (PACE) loan program has faced. The PACE program, started in 2008, provided loans to California homeowners to fund energy-efficient home improvements that could be repaid through the home's property tax bill. However, applicants for PACE financing often encounter difficulties with obtaining the subordination of their home loans to PACE financing and there were allegations of abuse of the program (kickbacks to contractors, misleading homeowners on the loan requirements etc.).

Monday, May 14, 2018

2018 Prince William County Wells

On May 8th 2018 we had the results meeting for the 2018 Prince William County Water Clinic. What we 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. The chart below shows what was found in the 114 samples tested in Prince William County in April 2018.
 In order to determine if treatment is necessary, water test results should be compared to a standard. The standard we use is 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.

The 2018 Prince William County water clinic found that almost 22% of the wells tested present for coliform bacteria. 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 home 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 water 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 the well, failed grouting or surface drainage to the well. If your well had coliform bacteria present you should shock chlorinate the well, 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 filtration system. Disinfection 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.

Membrane filtration is the usual treatment for these parasites- a one micron or smaller membrane is required for this. There are new filter systems that combine carbon and one micron or smaller membrane a a special filter designed for this purpose. To ensure that a filter removes Cryptosporidium, you can look for "NSF 53" or "NSF 58" and the words "cyst reduction" or "cyst removal." Reverse osmosis can also accomplish parasite removal, but typically only treats one sink rather than a whole house, wastes a lot of water, and if your water is at all hard requires a water softening system.

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. None of the wells in our group of 114 samples had nitrate levels above the MCL. The MCL for nitrate is 10 mg/L. Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill from blue-baby syndrome and, if untreated, may die. Symptoms include shortness of breath and a blue ting to the skin common in blue-baby syndrome. The NO3 dissolves and moves easily through soil which varies seasonally and over time as plants use up the nitrate over the summer. Testing in the spring will usually produce the highest levels. Nitrate may indicate contamination from septic tanks, but do not boil the water- boiling water reduces the water and actually INCREASES the concentration of nitrates. Reverse osmosis, or ion exchange is necessary to control the nitrate. None of the wells tested exceeded the MCL.

This year we had 7% of homes have 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 none 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. In the homes that had elevated lead in the first draw, it tends to be negatively correlated with pH values and copper pipes. 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 well components, but can also result from flaking of scale from brass fittings and well components unrelated to corrosion and corrosion control techniques such as adjusting pH or alkalinity that are commonly used to neutralize aggressive water will not work in those cases. For most instances, though, a neutralizing filter and lead removing activated carbon filters can be used to remove lead. 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. 11.4% of the wells tested exceed the iron standard and 3.5% 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 not recommended for just this purpose. 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 7.5. 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 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. The sodium based systems will increase the salt content in the water. 6.1% 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. As the mineral level climbs, bath soap combines with the minerals and forms a pasty scum that accumulates on bathtubs and sinks. You either must use more soap and detergent in washing or use specially formulated hard water soap solutions. 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. One well tested at 571.7 mg/L, but overall 18.4% of homes tested had hard water. 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.

Water softening systems are used to address the problem are basically an ion exchange system. The water softening system consists of a mineral tank and a brine tank. The water supply pipe is connected to the mineral tank so that water coming into the house must pass through the tank before it can be used. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions 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 is often used to charge the resin beads. Water softeners can be used to remove small amounts of other metals like iron and some forms of arsenic. As the water is softened, the sodium ions are replaced and small quantities of sodium are released into the softened water, thus the salty taste of softened water. When the water softening system is recharged the excess sodium solution carrying the calcium and magnesium is flushed to the septic system which may shorten the life of the drain field.

At the present time the EPA guidance level for sodium in drinking water is 20 mg/L. This level was developed for those restricted to a total sodium intake of 500 mg/day and does not necessarily represent a necessary level for the rest of the population. Based on taste of the water levels of sodium should be below 30 to 60 mg/L based on individual taste. Water softeners are often sold to solve every water quality problem because they have some ability to remove other contaminants and are quite profitable. The resin bed used will determine specific contaminant removal. Softened water can have a low pH and high levels of chloride, corrosion control problems and softening systems can encourage the growth of reducing bacteria. Water softening systems add sodium. Reverse osmosis systems and distillation systems remove sodium and are safe for household use, but addressing hard water by using vinegar to descale pots and dishwashers, regularly draining hot water heaters, and using detergents formulated for hard water might be a better solution for you if your water like mine is only modestly hard.

No 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 can also be an indication of industrial or pesticide contamination. Arsenic can be very tricky to remove depending on its form and the other contaminants present. Possible solutions for elevated levels of naturally occurring arsenic are reverse osmosis system or iron oxide filter system.

Thursday, May 10, 2018

Trying to Save a Tree from Emerald Ash Borer

The ash tree (left) in my side yard
This spring when I walked my garden assessing the winter and storm damage from the past two years I noticed the D shaped exit holes that are the signs of Emerald Ash Borer infestation on the ash tree on the side of my house. I love that tree and want to save it. Fortunately, I noticed the infestation while there is still hope.

Over the past few years the woods covering the back 7 acres of my land had become infested with Emerald Ash Borer. I noticed the damage first the summer before last when I was cleaning out trash from the river. The trees in my wood cannot be saved, but maybe there is still hope for the big ash on the side of the house. I called an arborist at “SavATree” to see what could be done. Pesticides can be applied to individual trees to protect them against Emerald Ash Borer and reportedly can save an ornamental lawn tree. For the pesticides to work the trees must be healthy and have at least 30% of their leaf canopy remaining. There is more than that on my ash.

The Emerald Ash Borer was first found in Prince William County in 2010. In the following years it spread across the county. At this point many ash trees in the county show the symptoms of infestation; epicormic branching (water sprouts), canopy die back, woodpecker damage, and bark splits. To tell if you have Emerald Ash Borer in your trees look for the 1/8th inch diameter D shaped exit hole and larval galleries that are the signs of Emerald Ash Borer infestation.

According to the Forest Service, protocol in areas were groundwater is used for drinking water is for either emamectin benzoate or a specific formulation of imidacloprid to be injected directly into the base of the tree trunk. The insecticide is transported within the vascular system of the tree from the roots and trunk to the branches and leaves- if it works. This reduces hazards to groundwater and to other plants from drift and protects the applicator from exposure, and has less impact on beneficial insects and other non-target organisms (like me).

Imidacloprid is not particularly soluble in water. The pesticide profile presented in the Extension Toxicology Network Pesticide Information guide concluded there is generally not a high risk of groundwater contamination when products are used as directed and appropriate precautions are taken. Similarly, the Canadian Water Quality Guidelines for the Protection of Aquatic Life noted that when imidacloprid is used correctly, it does not characteristically leach into soil layers leaving the groundwater unimpacted.

Drilling through the outer bark of the ash tree creates a wound in the tree. The response of the tree to these wounds is affected by factors such as the size and depth of the hole and the health of the tree. In recent studies, the injury associated with drilling holes and injecting two insecticide products into trunks of ash trees was examined. In nearly all cases, ash trees that were relatively healthy and properly injected showed little evidence of damage. New, healthy wood was produced over the injection sites and there was no evidence of pathogen infection, decay, or other signs of serious injury.
The ash tree is very near my well head

These injections should take place in late spring when the canopy is full. That should be in a couple of weeks or so. It is reported by the Forest Service that tree injections are tolerated in healthy green ash trees, especially if treatments are applied once every two years, small volumes of product are injected, and injection holes are small and shallow. That is the plan.

Monday, May 7, 2018

Virginia will Plan for Water

Thanks to a recently passed law every county in Virginia must plan to have adequate and sustainable water available for all their businesses and citizens. Water is our most valuable resource and how we manage its use or allow its abuse may determine the fate of mankind. The earth's total water supply is vast, estimated to be about 333 million cubic miles of water, over 96 % of which is saltwater. Fresh water represents only 4% of the total water of the earth. Over two thirds of the freshwater on earth (68%), is locked up in ice and glaciers (until they melt), about 30% of freshwater is in the ground as groundwater, and surface-water sources, such as rivers, streams and lakes, only represent about 2% of the fresh water and 1/10,000th of 1% of the total water on earth. The fresh water available on earth for mankind to use is finite, though constantly renewed by rainfall and snowmelt. Groundwater supplies can become polluted or be overdrawn and the soils through subsidence can lose the capacity to store water or be recharged.

According to the US Geological Survey about 26 % of the freshwater used in the United States in 2000 came from ground-water sources; the other 74 % came from surface water. Groundwater is an important natural resource and in nature serves to supply base streamflow during dry periods. Groundwater is a renewable resource, but not in the way that sun light is. Groundwater recharges at various rates from precipitation and other sources of infiltration.

The US Geological Survey estimated that the nation receives about a trillion gallons of recharge to the groundwater aquifers each day. (USGS circular 415). The recharge is not spread evenly across the nation or even where the water is needed. There limits to the amount of groundwater available for extraction from the aquifer. The amount of groundwater removed from an aquifer needs to be sustainable and should ideally match the recharge rate.

Groundwater availability and recharge rates vary locally and regionally and can be impacted by man. Over pumping of groundwater in the Costal Plain has lowered the groundwater tables for both aquifers. In the confined artesian system, the result has been salt water intrusion in areas. Development often is characterized by pavement and building that prevents the infiltration of precipitation that occurred before development.

In some regions groundwater that is currently being pumped was stored in the aquifer a millennia ago when the climate in that area was wetter. That water is not being replaced under current climate conditions and may ultimately be used up. Centralized wastewater systems further compound the problem by collecting the used groundwater, treating it and releasing the water into a stream or to the ocean in costal areas rather than distributed infiltration back into the ground by septic systems.

Our freshwater resources need to be managed as a whole. The utilization of groundwater resources in an unsustainable manner can result in impacts to the entire region, including the decrease in water level and aquifer storage, reductions in stream flow and lake levels, loss of wetland and riparian ecosystems, land subsidence, saltwater intrusion and changes in groundwater quality. Each watershed is unique and must be managed individually, and the data necessary to understand and manage water resources must be gathered locally over time to track and respond to changes in groundwater quantity and quality as well as stream flow.

This past winter the Virginia Legislature passed SB 211 which was signed into law by the Governor. This bill amends the enabling legislation for comprehensive planning to emphasize availability, quality and sustainability of groundwater and surface water resources on a County level as part of the comprehensive plan.

Comprehensive planning is already required and is not new. Groundwater and surface water are protected under current legislation. This bill makes one change to current law: in preparation of a comprehensive plan, the local planning commission must consider not only groundwater and surface water; but groundwater and surface water availability, quality and sustainability.

This bill carried by Senator Stuart and part of the legislative agenda endorsed by the Virginia Association of Conservation Districts Board of Directors on September 20, 2017 and ratified by the membership at their annual meeting in December 2017.

Virginia is dependent on groundwater. According to Virginia Tech there are approximately 1.7 million Virginians who get their water from a private well. In addition, according to the U.S. Geological Survey there are almost 750,000 Virginians who get their water from public and private community supply groundwater wells. In total that means that approximately 30% of Virginians are entirely dependent on groundwater for their drinking water.

Our other communities are dependent on surface water or a mix of groundwater and surface water. Surface and groundwater resources are limited. Having a comprehensive plan that lets people run out of water or has inadequate water to meet current or future zoning and planned development is not much of a plan.

Water resources can only be managed on a local level. There are already problems with availability, quality and sustainability of groundwater in Virginia in places such as Fauquier County, Loudoun County and the Coastal Plain. In addition, there is new information that was not previously available. Using their satellites, NASA can now measure groundwater depletion from space. They found that over the ten years (2003-2013) all of Virginia’s groundwater aquifers were being depleted, using groundwater faster than it was being recharged.

Thursday, May 3, 2018

Water Use in the United States 2015- fewer use private wells

The U.S. Geological Survey (USGS) has estimated water use in the United States every 5 years since 1950. The USGS has recently released some of the data for 2015 in an interim report. This report provides an overview of total population, public-supply use, and self-supplied domestic water use in the United States for 2015.

Total water for public supply were about 39,200 million gallons per day (Mgal/day) in 2015 (Dieter and others, 2017). Sixty-one percent of these withdrawals were from fresh surface-water sources (24,000 Mgal/day), 38 % were from fresh groundwater sources (14,900 Mgal/day), less than 1% was from saline groundwater sources (263 Mgal/day), and less than 0.5% was from saline surface-water sources (7.21 Mgal/day). Sixty percent or almost 23,300 Mgal/day of the total public-supply withdrawals were delivered to homes.

The average domestic use of water for people on public supplied water was 82 gallons per person. The range of use of water was huge, domestic per capita use ranged from 35 gallons/day in Connecticut to 184 gallons/day in Idaho. From 2010 to 2015, California reported a 17% decrease in total domestic use of water. In 2015, California was enduring one of the worst drought years on record and mandatory water restriction went into effect in 2014.

In 2015, the total population of the United States, reported by the U.S. Census Bureau, was about 325 million people. There were nine states with populations of more than 10 million people each: California, Texas, Florida, New York, Illinois, Pennsylvania, Ohio, Georgia, and North Carolina. The population in these nine states totaled 164 million people, or 51% of the total population of the United States. During a period where the total population of the United States increased 4 %, or approximately 12 million people, from 2010 (313 million people) to 2015 (325 million people), the number of people using private wells fell.

The domestic self-supplied population decreased by 1.4 million people from 44.0 million people in 2010 to 42.6 million people in 2015. This was a 3% reduction in the number of people who supply their own water. The domestic self-supplied withdrawals decreased eve more , 9 % from 3,570 Mgal/day in 2010 to 3,260 Mgal/day in 2015. This represents a continued decline in self-supplied domestic withdrawals observed from 2005 to 2010 (Maupin and others, 2014). Total domestic self-supplied withdrawals in 2015 were at the lowest levels since prior to 1980 (approximately 3,400 Mgal/day) when the total population was much smaller. Today, an estimated 42.6 million people in the United States, or 13 % of the population, provided their own water for domestic use in 2015.