Thursday, June 21, 2018

Health of the Chesapeake Bay



Last Friday the University of Maryland Center for Environmental Science released their 11th annual report card on the health of the Chesapeake Bay. Overall, in 2017 the Chesapeake Bay Scored 54% for the University’s Health Index, the same score as 2016. There are seven indicators that make up the Bay Health Index for the Chesapeake Bay Report Card; total phosphorus, total nitrogen, dissolved oxygen, water clarity, benthic community, chlorophyll and aquatic grasses. Each indicator is compared to scientifically derived thresholds or goals and scored to determine the overall grade.

Total phosphorus, total nitrogen, dissolved oxygen, and aquatic grasses are showing positive improvements. These improvements are encouraging for water quality, and have positive impacts on the ecosystem. Water clarity and chlorophyll a have significantly declining trends. Benthic community shows no significant change in health over time.

Overall Chesapeake Bay Health Scores have been variable in the past and bounced around a bit. However, since 2015, Chesapeake Bay Health Scores have consistently been in the high C range (53, 54, 54). These consecutive scores have contributed to an overall positive trajectory based on the average trend as seen below. It does seem odd that the Chesapeake Bay health has seemingly lost the variability that characterized it in the past. This may be an indication of the method of evaluation. I think more time is necessary to actually see if the current trend is sustainable and if the Health Index can break out of the range it has been stuck in for two decades

Over the years there have been changes in the methods of evaluation. Going forward, University of Maryland Center for Environmental Science plans to improve the Chesapeake Bay Report Card over the next several years. This process will incorporate new indicators for Chesapeake Bay health including some indicators of watershed health.

The new indicators are planned to reflect goals for sustainable fisheries, healthy watersheds, and engaged communities outlined in the Chesapeake Bay Agreement. The planned stakeholder-centered approach will hopefully allow for a stronger report card and improved understanding of how ecosystem health interacts with other factors throughout the Chesapeake watershed.


Monday, June 18, 2018

Anacostia River Health Improves



For the first time in the almost 20 years that the Anacostia Watershed Society has been grading the health of the River, the Anacostia River received a passing grade in overall health. The grade a 63, or D- for levels of toxins, trash and other environmental issues is a noteworthy improvement.

In truth there are limits when creating water quality scores because many of the variables that impact water quality are impacted by the intensity and frequency of rain. More heavy rain storms result in more sewer overflows and an increase in polluted runoff from streets and parking lots. So the comparison of indicators for wet and dry years can mask the underlying conditions and trends. Long term trends are generally more helpful and reliable for understanding the river.

The grade for the overall health of the Anacostia River has gone from 44 in 2014 to 63 in 2018. Despite the various weather patterns we’ve seen in the past 5 years, dry weather or wet, the trend of water clarity have been improving gradually and steadily. The long­ term improving trend toward clearer water was also seen in the return of submerged aquatic vegetation or underwater grasses seen in the 2015 Report Card for the first time since they disappeared from the Anacostia River in 2003.

Next year, the Anacostia Watershed Society expects even greater improvement in the River’s health. That’s because DC Water opened the new 7-mile-long, 23-foot-wide tunnel that runs between RFK Stadium and the Blue Plains Wastewater Treatment Plant on March 20th this year, too late to be counted in the river assessment. According to John Cassidy, program for the Clean River Project at DC Water, since opening, the Anacostia sewage tunnels have prevented about a billion gallons of combined-sewer overflow from being dumped into the Anacostia River. This is amazing progress on reducing fecal bacteria in the river. The tunnels should also help reduce stormwater runoff in coming years.

Due to the age of the Washington DC sewer system, parts of those systems are what is called combined systems where sewer and stormwater are carried through the same pipes. In the past, when it rains, untreated sewage and stormwater (combined sewage) was discharged into Washington DC’s rivers and creeks. The storage tunnel system are "diversion facilities" at strategic locations to capture this untreated sewage and divert it to the tunnel system where it can be stored and conveyed to the Blue Plains Advanced Wastewater Treatment Plant for treatment when the capacity is available.

Progress on trash reduction has been slow. Efforts have included installing trash traps in Washington DC and charging fees on plastic bags in Washington DC and Montgomery County. Now, the local jurisdictions have new laws that prohibit the use of Styrofoam as food and beverage containers. The proliferation of beverage containers in river trash is a major problem. Non-floatable trash is also a significant problem; trash monitoring shows 70% of trash by count is non-­floatable.

Year after year at the annual Earth Day cleanup volunteers remove tons of trash from the river. More work needs to be done to address this and it seems we need to change our behavior. Our food packaging and trashing habits need to change so that food wrappers (chip bags, etc.) cup, bottles and cans will not be dropped on the ground, tossed out car windows, or carelessly discarded.

The Anacostia Watershed Society was founded in 1989

Thursday, June 14, 2018

A Wet Year

The Washington Post recently reported that due the very rainy few weeks we just had, the Potomac river hit its highest levels since March 2010 in areas all over the Washington, D.C. area. The Interstate Commission on the Potomac River Basin (ICPRB) reports that we have water and that there is a below normal probability of needing water from the Washington metropolitan area’s back-up water supply reservoirs for the 2018 summer and fall seasons.

Our backup water supply is held in the Jennings Randolph and Little Seneca reservoirs. The need to release water from the reservoirs is triggered by low river flows brought about by a combination of low summer precipitation and low groundwater levels.

This year the average precipitation in the Potomac basin has been significantly above normal for the month of May. Recent rainfall has caused flooding in many areas of the basin. Streamflow data from the U.S. Geological Survey shows that flows are above or much above normal. Their gauges reported that the flow rate of the Potomac at Goose Creek was over 4 times the long term median, and at Point of Rocks the flow of the Potomac River was over 3 times the long term median.

Groundwater levels are near normal. According to the Middle Atlantic River Forecast Center, the outlook for water resources and water supplies is good in the Potomac Basin. At present, there is sufficient flow in the Potomac River to meet the Washington metropolitan area’s water demands without augmentation from upstream reservoirs. The latest U.S. Drought Monitor did not report any areas of Virginia in drought or even dry.

Data from the National Weather Service’s Middle Atlantic River Forecast Center (MARFC) shows that the Potomac basin upstream of Washington, D.C. has received a precipitation total above normal for April, and that precipitation was abundant for the month of May. In the past week alone, heavy rain (generally 2-6 inches over the region, and locally much greater) fell across much of Virginia, Although southern Virginia did not receive the very heavy rainfall that was reported just to its north, it still received enough to eliminate any residual dryness. Finally, it looks like we’ve got your wet year to recharge the basin. 

The ICPRB, through its Section for Cooperative Water Supply Operations on the Potomac, coordinates water supply operations for the regional water utilities during times of drought and recommends releases of stored water. These operations ensure adequate water supplies for Washington metropolitan area water users and for environmental flow levels. The water supply outlooks are published on a monthly basis between April and October.

Monday, June 11, 2018

Signs that a Well is Going Dry

The most common reason a well stops producing water is a mechanical problem like pump failure, pressure switch failure, loss of power or other mechanical problem. Failure of the well itself is rarely sudden, but rather happens slowly over time. If your water supply has lost pressure, and seems to be drizzling out of your faucet your problem could simply be a loss of pressure in the pressure tank from damage to or a leak in the bladder or simply a failed pressure switch. If your water pulses as it comes out of the faucet, the most likely cause is short cycling of the pump, which could be caused by inadequate water supply as the well goes dry or another faulty component in the system like the pressure switch. However, there are times that the problem is the well and the water supply. The major signs that a well is going dry are:
  1. Water pulsing or sputtering out of the faucet. 
  2. The water is muddy and filled with sediment and sand. 
  3. Loss of water pressure after doing laundry and bathing, but restored water overnight 
As mentioned above, these can also be signs of other problems, so actually measuring the water level and recharge rate in your well should be done before you spend money replacing equipment or thinking of drilling a new well. In a well, a diminished water supply can be caused by drop in water level in the well due to drought or over pumping of the aquifer, or the well could be failing in several other ways.

The water level in a groundwater well usually fluctuates naturally during the year. Groundwater levels tend to be highest in the early spring. Groundwater levels begin to fall in May and typically continue to decline during summer. Natural groundwater levels usually reach their lowest point in late September or October when fall rains begin to recharge the groundwater again. The natural fluctuations of groundwater levels are most pronounced in shallow wells that are most susceptible to drought. Older wells tend to be shallower.

However, deeper wells can also be impacted by an extended drought. Land use changes that increase impervious cover and stormwater velocity preventing recharge from occurring over a wide area and can make existing wells more susceptible to drought. Significant increases in groundwater use can overtax and aquifer.

Unless there is an earthquake or other geological event groundwater changes are not abrupt and problems with water supply tend to happen slowly over time. If your well tends to dry out during the summer when you try to do a load of laundry, you might want to address the problem before there is a drought when your well is likely to go dry. Addressing the problem could be as simple as implementing water conservation measures, or could require replacing water fixtures, lowering a pump or deepening or replacing the well.

In a well, a diminished water supply in a failing well is characterized by a short period of adequate water in the morning (or after resting the well for hours or days) and then almost a complete loss of water. Most modern pumps will automatically shut off when the well runs out of water. This is why a dry well is often mistaken for a failed pump.

Another symptom of a drying out well is loss of water after doing a load or two of laundry. (A top loading washing machine uses about 51 gallons of water and a front loader uses 27 gallons.) What is happening is overnight the well bore hole is filling with as much water as it can still produce and when there is water in the bore hole the pump will turn on in response to the pressure switch and the pressure tank gets filled. Even a tenth of a gallon a minute will still be able to fill the pressure tank overnight and give you enough water for a bit of a wash up in the morning (depending on whether you have low flow toilets, sinks and showers).

  • This low flow to the well can be caused by many things some which are fixable, some which are not: 
  • A drop in water level in the well due to drought or over pumping of the aquifer. 
  • The fractures that feed water to the well could be failing due to a buildup of dirt, sediment and gravel reducing the flow to the well. 
  • There are times that the steel casing that lines the first 40-60 feet of a well does not extend deep enough and the well walls crumble over time filling the well with dirt and gravel. 
  • Geological events can cause a sudden failure of a well. 

One or more of these factors could be the cause of a well problem. If your water loss seems to be from failure of the well itself, the first step is to call a well driller and measure the water level and recharge rate of the well. That information will tell you what you are dealing with and what choices you have to fix the problem. For the next steps


Thursday, June 7, 2018

Water Level Shows Seasonality and Rain’s Impact on Wells



The recent rains in this part of Virginia not only allowed me to find four leaks in my roof where the solar panel rack was not flashed and the black jack finally failed, but also restored the groundwater aquifer to 8 feet below grade after a dry winter when levels fell to 12 feet below grade. If your water is supplied by a well, you need to be aware of the condition of the groundwater aquifer that supplies your well and live within your water resources. There are dry years and wet years and water will vary, though it is not always obvious.

The groundwater aquifer you tap for water is not seen, but you still need to be aware of your water budget and live within it. The daily household water needs here in Virginia is about 75 gallons/day per person according to the U.S. Geological Survey. The water level in the aquifer that supplies a well does not always stay the same. Droughts, seasonal variations in rainfall, and pumping affect the level of the water table as you can see in the graph above. If a well is pumped at a faster rate than the aquifer around it is recharged by precipitation or other underground flow, then water levels in the well can fall. This is what happens during times of drought and dry spells when there is little or no rain.

The quantity and quality of ground water in Prince William County varies across the county depending on the geologic and hydrogeologic group you are in. Within the county there are four distinct geologic provinces: (1) the Blue Ridge, (2) the Culpeper Basin, (3) the Piedmont, and (4) the Coastal Plain. The U.S. Geological Survey divides the four geologic provinces of the county into seven hydrogeologic groups based on the presence and movement of the ground water calling them groups: A, B, B1, C, D, E and F. The age of the groundwater in your well is dependent on the hydrogeologic group.

Direct determination of the groundwater level in your well requires a water level meter which most of us do not have, but a less direct indication of the status of your well might be obtained from a proxy well. The U.S. Geological Survey, USGS, maintains a group of 171 groundwater monitoring wells in Virginia that measure groundwater conditions daily and can be viewed online. One of the Virginia wells is just up the road from me in the same hydrogeologic group and the ten year history of the well can be seen above. The seasonality of groundwater wells can be clearly seen in the graph.

The water level in a groundwater wells naturally fluctuates during the year. Groundwater levels tend to be highest in the early spring after winter snowmelt and spring rainfall when the groundwater is recharged. Groundwater levels begin to fall in May and typically continue to decline during summer as plants and trees use the available shallow groundwater to grow and streamflow draws water. Natural groundwater levels usually reach their lowest point in late September or October when fall rains begin to recharge the groundwater again. It is concerning that the monitoring well recorded several extreme lows.

This well is in hydrogeologic group B in the northwestern part of Prince William County and consists of sedimentary rocks of the Culpeper Basin. The predominant rock types are conglomerates, sandstones, siltstones, shales, and argillaceous limestones. This is a fractured rock system with moderate to excellent water-bearing potential with very little overburden. The highest reported yields in the county are from wells located in hydrogeologic group B and this is where I live. The downside to this formation is that the hydrogeologic group is susceptible to contamination- the fractures that carry water can easily spread a contaminant and without adequate overburden spills could flow to depth through a fracture. Another potential problem is in an extended drought there is limited storage, recharge is quick, though. As you can see below in hydrogeologic group B, the storms of this past April and May are clearly visible in the well monitoring data.


Monday, June 4, 2018

Study Reveals Possible Cause of Induced Earthquakes in Oklahoma

Oklahoma has been the site of thousands of earthquakes associated with the deep injection of wastewater from hydraulic fracturing or more commonly fracking. This induced seismicity, has been puzzling to seismologists because most of the earthquakes have not occurred on known faults, making seismic hazards difficult to estimate, predict or prevent by choosing a "safer" geology. Now, in a recently published study the U.S. Geological Survey and the Oklahoma Geological Survey believe that they have identified a potential cause of these earthquakes.

In hydraulic fracking on average 2.5-5 million gallons of chemicals and water is pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. While geologists and engineers believe that there is little risk that the fracking itself will cause an earthquake in areas not associated with known faults,  now concern is focused in on the disposal of the flowback water that has be found to induce earthquakes in ways we do not yet fully understand.

Airborne magnetic surveys were conducted in Oklahoma from August 11th, 2017-October 28th, 2017. The U.S. Geological Survey (USGS) and the Oklahoma Geological Survey (OGS) used the airborne magnetic data to image rocks where the earthquakes are occurring miles beneath the surface. The magnetic maps created reveal boundaries or contacts between different rock types, some of which are linear, similar to faults. A number of these types of contacts, are aligned with sequences of earthquakes. This suggests that some of them represent ancient faults that have been reactivated due to wastewater injection, which generates, or “induces” earthquakes.

According to USGS scientist Anji Shah, lead author for the study, the data show that there is a dominant “grain” direction to the magnetic contacts (like wood grain) in the deep rocks where the earthquakes are occurring. This “grain” was formed hundreds of millions of years ago and may be composed in part by faults that are oriented favorably to move in response to natural background stresses within the earth. This alignment of deep features may contribute to the high levels of seismicity occurring in response to the fracking wastewater injection.

According to Dr. Jeremy Boak of the OGS the scientists are hoping to be able to use this data to ultimately find answers to “some of the mysteries of induced seismicity in Oklahoma,” They are hoping to be able “ ... to bring these data to bear on addressing the persistent seismic activity and sharing our interpretations with Oklahomans and other stakeholders regarding this challenging issue.”

Many of the possible deep faults highlighted by the magnetic data are different from those on previous fault maps. According to the USGS this discrepancy is probably because the previous maps reflect relatively young faults in the shallow rocks, whereas the magnetic data image the deeper, older rocks. The USGS attributes the differences in the fault directions between these rock types to the different histories of ancient tectonic and magmatic events that shaped the rocks.

The citing for the research is:

Shah, A.K., and Finn, C.A., 2018, Airborne Magnetic Surveys over Oklahoma, 2017: U.S. Geological Survey data release, https://doi.org/10.5066/F7ZG6RJP

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.