Thursday, November 29, 2018

Explore Climate Projections on a Local Level

The following are excerpts from Volume I and II, of the Fourth National Climate Assessment. Volume I released last year, provides a detailed analysis of how climate change is affecting the physical earth system across the United States and provides the science that the assessment of impacts in in Volume II is based.
Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, B. DeAngelo, S. Doherty, K. Hayhoe, R. Horton, J.P. Kossin, P.C. Taylor, A.M. Waple, and C.P. Weaver, 2017: Executive summary. In: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 12-34, doi: 10.7930/J0DJ5CTG.

“Our world is warming overall, but temperatures are not increasing at the same rate everywhere. The average global temperature is projected to continue increasing throughout the remainder of this century due to greenhouse gas (GHG) emissions from human activities; however, high latitudes are expected to continue warming more than lower latitudes; coastal and island regions are expected to warm less than interior continent regions.”

“Climate models differ in the way they represent various processes (for example, cloud properties, ocean circulation, and aerosol effects). Additionally, climate sensitivity, or how much the climate will warm with a given increase in GHGs (often a doubling of GHG from preindustrial levels), is still a major source of uncertainty. As a result, different models produce small differences in projections of global average change. Scientists often use multiple models to account for the variability and represent this as a range of projected outcomes. Finally, there is always the possibility that there are processes and feedbacks not yet being included in projections of climate in the future.”

“The figure below from the shows the Fourth National Climate Assessment shows annual average surface temperature for the contiguous U.S. (black line) from 1960 to 2017, and the long-term warming trend (red line).”

 However, as you can see in the chart from the same report the warming has not been uniform across the nation. 

“Because warmer air can hold more moisture, heavy rainfall events have become more frequent and severe in some areas and 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.”

The bottom line here is no matter what mankind does, in the next couple of decades the expected impacts from climate change and are going to happen. The only future mankind actions can impact at this point are in the second half of the 21st century.

“Because Earth’s climate system still has more energy entering than leaving, global warming has not yet equilibrated to the load of increased greenhouse gases that have already accumulated in the atmosphere (for example, the oceans are still warming over many layers from surface to depth). Some greenhouse gases have long lifetimes (for example, carbon dioxide can reside in the atmosphere for a century or more). Thus, even if the emissions of greenhouse gases were to be sharply curtailed to bring them back to natural levels, it is estimated that Earth will continue warming more than an additional 1°F by 2100.”

So, this brings me to the really cool aspect of the Fourth National Climate Assessment- Climate Explorer. "With advances in computing power, the future effects of climate change can be projected more accurately for local communities down to the county level or you can look at the projected future on a state level. You simply hit this link and the click on the state you are interested in. "Local high-resolution (downscaled) climate modeling was used to produce data at a scale of 1–20 miles. These projections show climate-related impacts at the local level and can be an important tool for community planners, decision-makers, or for choosing where you want to live. The “Climate Explorer, projection data are derived from the global climate modeling experiments known as the Coupled Model Intercomparison Project Phase 5 (CMIP5). In the updated version, graphs and maps will display county-scale data generated using a new statistical downscaling technique called Localized Constructed Analogs (LOCA).”

When we were choosing a community to retire in, I had to manually extrapolate to climate projections available and simply guess at what the future might bring to any location. We chose a location in Virginia and the new Climate Explorer tool produced a very satisfying report for our location. You might want to look at the climate forecasts for your location and make sure that you make a well informed decision of where to live.

Monday, November 26, 2018

Climate Science Special Report

Every four years the U.S. Global Change Research Program (USGCRP) delivers a report to Congress and the President that “1) integrates, evaluates, and interprets the findings of the Program…; 2) analyzes the effects of global change on the natural environment, agriculture, energy production and use, land and water resources, transportation, human health and welfare, human social systems, and biological diversity; and 3) analyzes current trends in global change, both human-induced and natural, and projects major trends for the subsequent 25 to 100 years.”.

On Friday the federal government released the Fourth National Climate Assessment Volume II. In 2017 volume I, of the Fourth National Climate Assessment was released. Volume I released last year, provides a detailed analysis of how climate change is affecting the physical earth system across the United States and provides the science that the assessment of impacts in in Volume II is based. Volume II focuses on the human welfare, societal, and environmental elements of climate change and examines the variability in observed and projected risks, impacts, and implications under different mitigation pathways. The report contains many examples of actions underway in communities across the United States to reduce the risks associated with climate change, increase resilience, and improve livelihoods that made me feel good.

The report is long!! I have only looked at a couple of chapters, and I believe that the two report together with the appendixes total more than 1,600 pages. You have three choices here go to your favorite news source and read their opinion to confirm whatever point of view you have. Or you could read the 196 page summary of findings  at the link below. I do, however recommend reading the 18 page summary of impacts.

Finally, if you might want to read the 62 page Frequently Asked Questions in Appendix 5 of Volume II which is an amazing summary of the entire topic of climate change and its implications. In 62 pages you are caught up with the entire field of study and are prepared to have opinions and make informed decisions in your life and talk intelligently at social gatherings. Topics covered are:
  • Introduction to climate change 
  • Temperature and Climate Projections 
  • Climate, Weather, and Extreme Events 
  • Societal Effects 
  • Ecological Effects

Volume I Citation:
Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, B. DeAngelo, S. Doherty, K. Hayhoe, R. Horton, J.P. Kossin, P.C. Taylor, A.M. Waple, and C.P. Weaver, 2017: Executive summary. In: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 12-34, doi: 10.7930/J0DJ5CTG.

Volume II Citation:
USGCRP, 2018: Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA. doi: 10.7930/NCA4.2018.

Thursday, November 22, 2018

Rules for Septic Systems

  1. Only toilet paper and human waste should go down the toilet. Do not flush wipes, facial tissues, paper towels, floss, cotton swabs or other items such as coffee grinds, kitty litter. 
  2. Do not use the garbage disposal to dispose of food scraps. A garbage disposal adds solids, grease and increases the biological load on a septic system. (Don’t ask me why they installed it, I use mine to break up soap bubbles.) 
  3. Do not put hazardous household wastes down the drain or in the toilet EVER. Do not wash paint brushes or containers in the sink. 
  4. Minimize the use of bleach, chemical disinfectants and antibacterial agents. As little as of 1.85 gallons of liquid bleach added to a 1,000-gallon septic tank can cause a die-off of the bacteria in a septic tank. 
  5. Never do more than two laundry loads a day. Laundry uses a lot of water and too much water in a single day will stir up to solids and scum and push them through the system. 
  6. Service your septic system regularly. At a minimum pump your septic tank every 3-5 years it will extend the life of your system.
The septic system is designed so that with proper maintenance it will last 20 to 30 years, but only if you treat it properly. Replacing a septic system is reported to cost $20,000-$40,000. The functioning of a septic system is based on natural ecological cycles. It needs to be treated kindly and kept in balance. When a system is that is not pumped out on a regular basis has an excessive demand put on it, sludge (solid material) flows into the leach (absorption) field, potentially clogging it beyond repair. Excessive load from toilets and garbage disposal, putting grease, coffee grinds, kitty litter or any kind of trash down the drain will effectively decrease the size of the tank and the time that the solids have to settle out. This will decrease the life of and potentially overload the system. Even with proper use and maintenance the system will wear out. A garbage disposal adds solids, grease and increases the biological load on a septic system.

A typical septic system has four main components: a pipe from the home, a septic tank, a leach field (alternative systems might have drip fields, sand mounds or peat tanks where a leach field is not possible or has failed), and the soil. Microbes in the soil digest or remove most contaminants from wastewater before it eventually reaches groundwater. Many systems also have pumps to move the liquids from the home to the septic tank or from the septic tank to the drain field. There are also Alternative systems that have additional components such as; float switches, pumps, and other electrical or mechanical components including additional treatment tanks.

The septic tank is a buried, watertight container typically made of concrete, fiberglass, or polyethylene. It holds the wastewater long enough to allow solids to settle out (forming sludge) and oil and grease to float to the surface (as scum). It also allows partial decomposition of the solid fecal materials. Compartments and a T-shaped outlet in the septic tank are intended to prevent the sludge and scum from leaving the tank and traveling into the leach field area. Some newer systems have screens and filters to keep solids from entering the leach field.

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 (multiple laundry loads or every relative you have taking a shower at the same time), there will not be enough time for the solids and liquids to settle out before the tank starts releasing waste. Water containing large amounts of fecal waste will be released to the drain field. Also, if there is too much grease and scum floating on top, the scum will be released to the leach field.

Monday, November 19, 2018

Flooding from Hurricane Florence

The U.S. Geological Survey has released their report: "Preliminary Peak Stage and Streamflow Data at Selected U.S. Geological Survey Streamgaging Stations in North and South Carolina for Flooding Following Hurricane Florence, September 2018." The report is by Toby D. Feaster, J. Curtis Weaver, Anthony J. Gotvald, and Katharine R. Kolb. The article below is from that report and the news release.
Area of Study for the report USGS

Early Friday morning on September 14, 2018, Hurricane Florence made landfall as a Category 1 hurricane at Wrightsville Beach, North Carolina (North Carolina Department of Public Safety, 2018). The storm was reported to be nearly 400 miles wide. Once over land, the forward motion of the hurricane slowed to about 2 to 3 miles per hour; and over the next several days, the hurricane drenched the Carolinas,  delivering historic amounts of rainfall across North and South Carolina. In many communities in both states this caused substantial flooding (Feaster and others USGS 2018).

The maximum 4-day rainfall total reached almost 36 inches in some areas of North Carolina and almost 24 inches in some areas of South Carolina, resulting in historic flooding in many communities within both States. In addition to the catastrophic flooding from Hurricane Florence, the coastal and central parts of North and South Carolina experienced previous catastrophic flooding over the years and recently in 2016 and 2015 from two other storm events. In October 2016, Hurricane Matthew brought heavy rainfall to the eastern and central parts of the Carolinas (Weaver and others, 2016). In October 2015 a low-pressure system over the Southeast funneled tropical moisture from Hurricane Joaquin into South Carolina causing historic rainfall amounts (Feaster and others, 2015), which resulted in historic flooding in the central and coastal parts of the State. The scientists at the USGS looked at stream flow data for gauges that had at least 10 years of data to look at both the magnitude of the flooding from Hurricane Florence and the probability of future flooding.
from USGS Feaster and others 2018
“Many of the new peaks of record set by Hurricane Florence broke previous records set by Hurricane Matthew in 2016,” said Toby Feaster, USGS Hydrologist and lead author of the study. “...Several of the 28 streamgage sites we analyzed had more than 30 years of historical data ..., it was interesting that a majority of the number one and two records were from back-to-back flooding events.”

There were some sites with more than 70 years of historical data that set new flood records, but there were others where the peak flood event was more than a hundred years ago. In North Carolina, French Broad River at Asheville, N.C., has one of the longest records with peak streamflows going back to 1896 (fig. 16 id from Feaster and others USGS 2018). The peak of record was recorded on July 16, 1916, at 23.1 ft and a peak streamflow of 110,000 ft3/second, which is about two and one-half times larger than the second largest peak that occurred on September 8, 2004. Historic information indicates the 1916 peak was likely the largest peak since at least 1791(Feaster and others USGS 2018). 

The new report analyzed the estimated annual exceedance probability for the Hurricane Florence peak streamflow to determine how likely a reoccurance at the 28 streamgages studied. They found that 9 of the streamgages was less than 0.2 percent, which in terms of recurrence intervals is greater than a 500-year flood event. At three streamgages, the estimated annual exceedance probability was equal to 0.2 percent, and at six streamgages, it was between 0.2 and 1 percent (between a 500- and 100-year recurrence interval, respectively). For the remaining 10 streamgages, the estimated annual exceedance probability was between 1.5 and 7.1 percent, which in terms of recurrence intervals is approximately a 67- to 14-year event, respectively (Feaster and others USGS 2018). Frequent flooding events is a given for the region and often these events occur with back to back storms. This would explain a real estate requirement that my husband learned from his father- that you should always live on high ground- My father-in-law's people were from North Carolina.

To read the full report see:

Feaster, T.D., Weaver, J.C., Gotvald, A.J., and Kolb, K.R., 2018, Preliminary peak stage and streamflow data for selected U.S. Geological Survey streamgaging stations in North and South Carolina for flooding following Hurricane Florence, September 2018: U.S. Geological Survey Open-File Report 2018–1172, 36 p.,

Thursday, November 15, 2018

Michael’s Damage and the Future of Hurricanes in the Atlantic

This past October, the Florida panhandle was hit with hurricane Michael. Storm surge, coastal erosion and inland flooding are among the most dangerous natural hazards unleashed by hurricanes. The USGS, the National Hurricane Center and other agencies closely monitor hurricanes. The USGS has computer models for forecasting the storm’s impact, and sophisticated equipment for monitoring actual flood and tide conditions. In addition, the USGS compares the National Oceanic and Atmospheric Administration coastal photos taken in 2017  to NOAA photos collected the day after Hurricane Michael made landfall in order to document the hurricane’s impact on the coast, and to fine-tune coastal change forecasting models.
Mexico Beach before Michael from USGS

Mexico Beach after Michael from USGS

When a storm is about to strike the U.S. Atlantic or Gulf coast, the team forecasts the likelihood of coastal erosion and other changes, using a computer model that incorporates the National Hurricane Center’s storm surge predictions and National Oceanic and Atmospheric Administration wave forecasts. The USGS model adds information about the beach slope and dune height to predict how high waves and surge will move up the beach. The model forecasts three types of storm impact to the dunes that protect coastal communities: erosion, overwash, and inundation, or flooding that reaches over and behind the dunes.

According to Kara Doran, the USGS Coastal Change Hazards team leader the low-altitude oblique photos give a clearer view of the beach and dunes. The USGS can see whether the storm surge and waves altered or eliminated that protective barrier, and what happened to the houses and roads behind the dunes. Though the destruction as seen above is shocking according to Doran the USGS’s preliminary analysis indicates that the forecasting models performed fairly well at predicating what areas would be affected by storm surge overtopped the dunes.

One area that saw significant coastal change that was not predicted by model was on T.H. Stone Memorial St. Joseph Peninsula State Park. As seen in the photos below, Michael’s rough waves and surge carved a new breach into the peninsula, washing out the road and turning part of the park into an island as seen below in the USGS photos.

It is not known if this kind of damage is the future of the coastal areas as the climate warms. According to NOAA, observed records of Atlantic hurricane activity show some correlation, on multi-year time-scales, between local tropical Atlantic sea surface temperatures and the power of the storms. "If this statistical relationship between Atlantic sea surface temperatures and hurricane activity is used to infer future changes in Atlantic hurricane activity, the implications are that the forecasted large increases in tropical Atlantic sea surface temperatures projected for the late 21st century would imply very substantial increases in hurricane destructive potential–roughly a 300% increase by 2100."

On the other hand, Swanson (2008) and others noted that Atlantic hurricane power dissipation is also well-correlated with other Atlantic sea surface temperature indices besides tropical Atlantic sea surface temperature alone. "This a crucial distinction, because the alternative statistical relationship between the hurricane destructive potential and the relative sea surface temperature measure implies only modest future long-term trends of Atlantic hurricane activity with climate warming. So, we don't really know."

From Department of the Interior, U.S. Geological Survey press release.

Monday, November 12, 2018

Life Expectancy of a Water Well

How long a well lasts depends on many factors; the geology and hydrology of the region, the amount of ground cover nearby, how the well was constructed, what equipment has been installed “down hole,” and what maintenance activities have been performed to date.

Prince William County first implemented county wide well construction regulations in 1970’s. Those regulations were very progressive for their time and quite similar to the current state wide regulation implemented in 1992 and still in effect today. When a well is drilled the well driller must fill out the “Water Well Completion Report.” This report is chock full of information about the well. Some of the information is : location, type and class of well, the well depth and diameter, the depth to bedrock, and total depth of casing, the presence and size of screen and or mesh, the location of water zones, the static water level (unpumped level measured) and the stabilized yield. The only water sampling that takes place under regulation is a coliform bacteria test after the well has been disinfected and the residual chlorine has dissipated.

As a water well ages, the rate at which water may be pumped referred to above as the well yield tends to decrease. The mechanical components and the well structure, screens and casing all age and deteriorate. Well maintenance and monitoring of the water and well’s performance is important in keeping the water flowing. A well owner must think about their well in terms of stewardship over the long term, long before your well fails.

To ensure water quality, well water should be tested annually for total coliform bacteria and E. coli bacteria by an accredited testing laboratory (states keep lists of accredited labs). Water wells should also be inspected annually for obvious signs of damage or contamination. Be sure the area within 100 feet around the well is clear of debris or items that might pollute the water supply. In addition, wells should have their static water level, pumping water level and flow rate tested and recorded when the well is new, and tracked occasionally over the years. Establishing benchmarks, for static and pumping water levels, flow rate, and specific capacity, is critical for tracking well performance and will help identify trouble long in advance of well failure. In most cases, the well owner will have several years to react to problems that are manifesting in the well and possibly take remedial action before it’s too late.

A well can last 50 years (I know of one well that did). However, a drop or complete loss of water production from a well can sometimes occur even in relatively young wells due to a lowered water level from persistent drought, nearby development, or over-pumping of the well which can dewater the water-bearing zones. More often, the fall in well yield over time can be caused by changes in the water well itself. According Penn State Extension these changes can include:
  • Encrustation by mineral deposits 
  • Bio-fouling by the growth of microorganisms 
  • Physical plugging of groundwater aquifer by sediment 
  • Well screen or casing corrosion 
  • Pump damage 
Monitoring of a well’s performance brings everything into view, good or bad, and should a well owner go for decades without major trouble, at monitoring over the years can give you peace of mind. Monitoring can prevent being surprised by well failure when, in a panic, patchwork or inappropriate work is done. Often the money spent on patchwork by the well owner is lost. Monitoring of the well’s performance allows for preventive maintenance.

Generally, a decrease of 25% or more in well yield indicates that rehabilitation of the well is needed. Delaying rehabilitation can significantly increase costs and in some cases make rehabilitation impossible. Measures taken to correct these problems are referred to as well rehabilitation or restoration. A successful well rehabilitation will maximize the flow of water from the well. The chances for successful rehabilitation are dependent on the cause or causes of poor well performance and the degree to which the problem has progressed.

The two most common methods to rehabilitate a water well are:
  • chemicals to dissolve the encrusting materials from the well 
  • physically cleaning the well 
Encrustation caused by mineral buildup or by bio-fouling are common causes of well failure. Encrustations are mineral deposits which buildup on well screens and in the rock fractures or openings that deliver water to the well. Mineral buildup is caused by minerals that fall out of solution depositing on the well screens and well fractures. The primary cause of bio-fouling, or biological clogging, of well screens and rock fractures is attributed to iron bacteria. These and other similar bacteria create a slimy bio-film. Avoiding this is why I regularly chlorine treat my well.

The usual methods for rehabilitation of chemical encrustation involves the use of strong acid solutions to dissolve encrusting materials combined with physical methods that include using a brush attached to a drilling rig, high pressure jetting, hydro fracturing of the well (hydrofracking), and well surging.

A portion of the loss in well performance over time can be caused by the accumulation of fine particles from the aquifer in the borehole and clogging the well screen. These particles can also cause pump damage, and result in short lifespan of replacement pumps. It may be necessary to replace the well screen or protect the pump. The most important preventative measure to avoid sediment from plugging a well is proper well development, as required by modern well regulations. A well developed and healthy well should not require a sediment filter.

Thursday, November 8, 2018

Water Rates Increase Unevenly in the Region

Most water and sewer utilities in our region are a separate, government enterprise fund established to be self-supporting. That means that the majority of their revenue is from charges for services provided to customers, including service charges, account charges, new connection charges and the charges for water and sewage by the gallon. These charges, both variable and fixed, are to cover the costs of renewing the buried pipes and distribution networks as well as the costs to operate and maintain the treatment plants.

Recently, Fairfax Water announced its intention to raise their water rates next spring. There will be a public hearing on Thursday, December 13, 2018, on the proposed rate increase held at Fairfax Water’s main office at 8570 Executive Park Avenue in Fairfax. This rate increase is part of their ongoing program to ensure that the water infrastructure in Fairfax County is maintained. The proposed rate increase will go into effect April 1. 2019.

The need for infrastructure replacement is an issue that has caused significant service problems and rate increases in other parts of the Washington Metropolitan region. Fairfax Water Board of Directors have dedicated funding to infrastructure maintenance and replacement for many years, and has forecast future capital needs for replacing water mains in the system. In addition, Fairfax Water is planning for additional water storage within their system by developing the Vulcan Quarry as a reservoir.

As they do every time they propose to raise water rates, Fairfax Water performed a comparison of the water costs throughout the Washington Metropolitan region. This comparison is based on rates as of July 1, 2018 and on 18,000 gallons of residential water use for an established account over a three month period. I also compared these rates to the comparison that was done in 2017.


Manassas Park continues to have the highest rates in the region, despite not have raised their rates last year. Manassas Park is a small utility system with fewer than 5,000 customers. In addition, tucked into that overhead is debt service for the city’s Enterprise Fund. Manassas Park is responsible for paying City utility bonds, and also to make the annual principal and interest payments on the bonds sold to build the City Schools, Police Station, and Fire Station & Community Center. While diverting water funds to other city needs, Manassas Park failed to properly maintain their water distribution system.

Water rates in Prince William from both the Service Authority and Virginia American Water have not increased in the past year and due to the method of calculating rates for comparison appear to have fallen slightly for Virginia American Water. The City of Manassas had a significant increase in rates as did the Town of Leesburg and Arlington. Customers should track their water utility to verify that rate increases are being appropriately applied to maintaining the infrastructure and operations and are not being diverted to other purposes as happened in Manassas Park. 

Monday, November 5, 2018

Water Treatment Systems- What should I buy?

Before even considering treating your well water, get a fairly comprehensive water analysis and test for iron bacteria. This provides you with a full list of the contaminants in your water, pH, hardness and other characteristics that might impact taste or water quality and the effectiveness of any water treatment equipment. Water treatment equipment is a commitment, in money and maintenance. Not only is proper selection of treatment equipment or system essential, but proper maintenance is also key. Treatment adds complexity to your system, which increases the items that can go wrong and the time necessary to ensure it is working properly.

At best, improperly maintained treatment equipment may not do its job. At worst, it can cause other problems with your water system. Improper equipment selection may cause other problems that in turn need to be treated. Sometimes, you might need or want treatment for a particular contaminant, but there might be other, contaminants or constituents in the water that affect how well certain treatment devices work or might be trying to treat water for iron when iron bacteria is the problem.

Contaminants that indicate potential or are health risk need to be addressed. Contaminants that are likely to cause some sort of aesthetic problem can be ignored in some cases. . Before deciding on treatment, you should determine exactly where contaminants are coming from. Some sources of contamination are obvious, others are not so obvious. Coliform bacteria, for example, or high chloride, could come from any number of sources. It’s always best to eliminate the source first. If you are able to do that, then continued, long-term treatment might not be needed.

Home treatment is typically either Point of Use (POU) or Point of Entry (POE). POE treatment is at the point where water enters the home and provides whole home treatment. This type of treatment is generally more expensive because you are treating more water. It’s necessary, however, if you are treating for a contaminant that impacts health or renders the water aesthetically unusable (E. coli, hydrogen sulfate, radon come to mind). POU units are typically used to treat water for drinking and cooking at a specific tap or faucet. These systems are used to treat a contaminant that is a health risk if ingested, or that might cause taste issues. They only treat a portion of the water coming into your home.

Filters are a common water treatment device that can be used for a number of different applications. Some are membrane filters or tight media that prevent particles or contaminants that are over a certain size from passing through. Others include media or resins that help bind or adsorb certain contaminants that are attracted to the media. Most whole house model water filters are pressure filters, a fully enclosed tank type filter that operates at the same pressure as the water delivery system so that you do not need to buy a booster pump or re-pressurize the water.

These devices are used for a variety of water treatment purposes such as taste and odor improvement, iron and manganese removal and removal of suspended matter (turbidity) in water. The water treatment performed by a pressure filter is determined by the filter media that is inside the tank.

Reverse osmosis is a point of use filtration through a membrane. It works by forcing water through a semi-permeable membrane that lets some molecules through, but prevents the contaminants from going through. These systems can remove uranium contamination, any many other contaminants. The effectiveness of a reverse osmosis system depends the type of membrane, the pressure pushing the water, and the quality of the source water. These systems do not work for bacteria, but are excellent for other larger contaminants. Reverse osmosis are usually mounted under kitchen sinks and waste between 4 and 10 gallons of water for every gallon of water treated.

If you buy a home with a well and preexisting water treatment equipment, you need to determine what your raw water looks like and if any existing equipment is needed, appropriate and working. The best way to begin is to test the water before any treatment equipment and after any treatment. Groundwater is dynamic and can change over time and equipment available for the home market has changed over the years.

Thursday, November 1, 2018

Fixing a Weird Smell or Oily Sheen in Well Water - why I regularly chlorinate my well

Some of the weirdest water problems turn out to be iron bacteria. Generally, iron bacteria produce unpleasant tastes and odors commonly reported as: "swampy," "oily or petroleum," "cucumber," "sewage," "rotten vegetation," or "musty." The taste or odor may be more noticeable after the water has not been used for some time and are not easily explained by other causes. There is often a discoloration of the water with the iron bacteria causing a slight yellow, orange, red or brown tint to the water. It is sometimes possible to see a rainbow colored, oil-like sheen on the water. Though the most classic symptom of iron bacteria is a rust colored slime, it may be yellow, brown, or grey. A quick screen for iron bacteria would be to feel the rubber flapper in your toilet tanks. The iron bacteria tends to accumulate there.

About six or seven years ago I tested my well water for iron bacteria. Though I test my well water each year during the annual water clinic the Prince William Extension Office hosts and every few years for all primary and secondary pollutants, iron bacteria is not part of those suite of tests. The standard bacteria tests do not test for iron bacteria. Iron bacteria assay test can be purchased from National Testing Laboratories for $59.99 these days (excluding shipping). My test found “Iron Related Bacteria” present with an estimated population of 2,300 cfu/mL.

Iron bacteria once introduced into the well will not get better, but continue to get worse destroying your pump and ultimately fouling the well. Iron bacteria can grow on pump intakes and screens openings causing plugging, corrosion, and reducing the yield and efficiency of the well. The iron bacteria can reduce well yield and damage well equipment. In addition, the slime produced by the iron bacteria reduces the ability of regular chlorine treatments to kill disease-causing organisms. Finally, though, there is no health risk associated with the bacteria, ultimately it will make the water unpleasant.

Iron bacteria can be introduced into a well during drilling, repair, or service if tools, equipment, or devices used during well drilling or pump servicing were not properly disinfected. It is believed that the bacteria must be introduced into the aquifer and cannot infect the water without human help.

Elimination of iron bacteria once a well is heavily infested can be extremely difficult. Iron bacteria cannot be eliminated by most common water filtration methods or water softeners. However, though it is difficult to eliminate, it is actually very easy to control – just oxidize the heck out of the well.

Normal treatment for a problem such as this would be to chlorine “shock,” but iron bacteria can be particularly persistent and chlorine treatment of the well may be only partly effective. Typically, a chlorine concentration of 50-200 parts per million is used for decontamination of a well impacted by coliform bacteria. A significantly higher concentration of chlorine is recommended by the literature for iron bacteria. Recommended concentrations are between 500-1,000 parts per million. Be warned that too high a concentration can make the well alkaline and reduce effectiveness, so don’t go crazy. In addition high concentrations of chlorine may affect water conditioning equipment, appliances such as dishwashers, and septic systems, so do not pull the heavily chlorinated water through equipment and the plumbing system.

The recommended strategy is to treat the well with a 500-1,000 parts per million chlorine hold for 12 hours and then dilute the remaining water in the well. This can be accomplished by allowing a significant amount of the water to runoff to a safe disposal location using hoses until the water runs clear. Use chlorine test strips to verify that there is still residual chlorine in the water and allow the well to refill and then introduce the water into the house water system to disinfect the household treatment units, appliances and piping with lower concentrations circulated through the water system and hold for an addition 12 hours. Flush the system completely using hoses not your drains and septic system.

The Idaho Water Resources Research Institute recommends an initial treatment at 1,000 ppm including scrubbing and disinfecting the pump and an annual maintenance disinfection of 500 ppm leaving the pump in place. My initial treatment was about 600-800 ppm with the pump in place for 12 hours and then running off the slimy rust colored crude that came out for a few hours, topping up the chlorine concentration to about 200 ppm and pulling the chlorinated water throughout the household plumbing system.

I chlorine treat the well ever couple of years to keep knocking back the iron bacteria. I gave up testing for the iron bacteria because it did not seem worth the expense. Because you never really get rid of iron bacteria, prevention is the best safeguard against the bacteria and their accompanying problems. The bacteria will eventually grow back so be prepared to repeat the shock treatments from time to time. With my well that translates to even years.

Chlorination for iron bacteria can also rehabilitate the well. As a water well ages, the rate at which water can be pumped (commonly referred to as the well yield) tends to fall. This can be caused by Incrustation from mineral deposits or bio-fouling by iron bacteria. The most common methods to rehabilitate a water well are: acids or chlorine to dissolve the encrusting materials and bacterial slime from the well; and physically cleaning the well.

Chlorination can dissolve the encrustations and extend pump function. These days regularly treating a well with chlorine is the recommended strategy to extend the life of a well and equipment and can improve the taste of the water. See well maintenance tips from Penn State University Extension. Last week with the help of someone who wanted to see how a well was chlorinated I chlorine shocked my well. Just in time before the cold weather.