A Million Gallons of Sewage Spill in Olney & 5 Million Gallons of Water Spill in Silver Spring

Last Tuesday, July 28, 2015 a resident near the Olney Theatre Center reported sewage coming up through the ground behind their home to the Washington Suburban Sanitary Commission (WSSC). A 20 inch pressurized sewer main was leaking. It was Wednesday morning before WSSC stopped the leak and by then about 460,000 gallons of raw sewage had been spilled. Within an hour the 20 inch sew main had sprung another leak about 100 feet away and another 534,000 gallons of sewage was spilled before that leak was stopped. WSSC repair crews located the second leak and repairs to the main were completed on Thursday.

from WSSC

By the time the sewer main was fixed, an estimated total volume of 994,226 gallons of raw sewage wastewater had been released. A portion of the sewage flowed into Lake Hallowell and James Creek. James Creek in turn feeds the Hawlings River, which joins the Patuxent River, then flows into WSSC’s T. Howard Duckett Reservoir, popularly known as Rocky Gorge. The clean-ups at the two break sites and the nearby Olney Wastewater Pumping Station have been completed, but WSSC is closing the Browns Bridge Recreation Area for 30 days. WSSC will also increase water testing to monitor the water quality of the stream, river and reservoirs and the drinking water they deliver to almost 2 million residents of Montgomery and Prince George Counties.

WSSC is confident that sewer spill, euphemistically called an “overflow” will not affect the drinking water. The raw sewage was diluted in the streams and will be further diluted by the 4.9 billion gallons of water in the Rocky Gorge Reservoir. In addition, WSSC points out that their water treatment includes filtration and disinfection as part of the process, and water testing is conducted continuously.

This sewage spill was almost 10 times the size of the average sewage spill in 2014. In 2014, WSSC experienced 160 “overflows” resulting in 8,028,449 gallons of untreated sewage being released. According to WSSC the majority of the “overflow” volume during 2014 was caused by instrumentation/mechanical failures and excess flow. Blockages in the pipes from grease, tree roots, and debris are the leading cause of “overflows” in WSSC's system, but sewer pipe failure, though less frequent causes larger spills.

In 2005 WSSC signed a consent decree with the U.S. Environmental Protection Agency (EPA) which required the WSSC to enact a 12-year plan to reduce sewage spills. Under the agreement, the entire plan is supposed to be carried out by late 2017, with most of the pipe rehabilitation work finished by later this year. Under the consent decree, WSSC was to rehabilitate (repair and replace) 274 miles of sewer pipe. However, as of January 2015 92 miles of pipe still need to be rehabilitated. WSSC sought an extension claiming that they were behind schedule because of the permitting delays. Or possibly, they just did not apply for the permits soon enough.

WSSC provides sewer service and drinking water to about 2 million people in a 1,000-square-mile area in Montgomery and Prince George's Counties. Their service area has approximately 5,400 miles of sewer mains that need to be maintained in addition, due to continued expansion and buildout of the region WSSC adds approximately 50 miles of new mains each year.

A couple hours after repairing the sewer main, a 16-inch water main on Colesville Road at Georgia Avenue in Silver Spring broke.  The 76-year-old pipe broke about 3:45 p.m. on Wednesday, and it took crews about 10 hours shut off the water, the shut-off valves were located under the water rushing from the break. Approximately 5 million gallons of water was lost. Though drinking water has been restored to all customers, work in the area will not be finished until later this week. WSSC’s contractor has been working 24 hour shifts since Wednesday.  

The broken section of pipe has been replaced and all other utilities in the area have been checked and repaired as necessary. WSSC reports that additional work will be finished on Monday because the latest concrete repairs need time to cure. Road paving and repair is expected to begin on Tuesday. Some of the traffic lanes northbound on Colesville Road and southbound on Georgia Avenue remain closed until the work is completed. Welcome to New Delhi, Maryland.

Potomac Watershed Roundtable- Reliability of Drinking Water Supply

On Friday, October 4th 2013 the Potomac Watershed Roundtable met at the offices of Loudoun Water in Ashburn, Virginia. Curtis Dalpra, Communications Manager for the Interstate Commission on the Potomac River Basin (ICPRB) presented the results of a study to examine what the impacts of Climate Change might be on Drinking Water Supplies in the Washington Metropolitan Area. Let’s back up to understand why and how this study was done.

Turn a tap in most places of the Washington Metropolitan region, and water, primarily from the Potomac River, flows. The system that today provides ample water to the area does not provide unlimited water. The water supply for the region will become less reliable in coming decades, especially during droughts, as the population continues to grow and as surface flow to the Potomac River decreases by changes in the land use of the watershed and changes in climate impact the river.

The Washington Metropolitan region population and development has reached the point that during times of drought, natural flows on the Potomac are not always sufficient to allow water withdrawals by the utilities (including power generation which takes an awesome amount of water) while still maintaining a minimum flow in the river for sustaining aquatic resources. ICPRB allocates and manages water resources of the river through the management of the jointly owned Jennings Randolph Reservoir (built in 1981), Potomac River Low Flow Allocation Agreement (1978) and the Water Supply Coordination Agreement in 1982 which designated a section of the ICPRB as responsible for allocating water resources during times of low flow. These steps improved reliability of the water supply and ensured maintenance of in-stream flows to meet minimum aquatic habitat requirements. The section of ICPRB responsible for all this is known as the Section for Cooperative Water Supply Operations on the Potomac (CO-OP.

An important aspect of the Water Supply Coordination Agreement of 1982 is periodically forecasting the region’s future needs for water and assessing the current water supply system’s ability to meet those needs. This analysis is conducted every five years to look 30 years in the future to incorporate new data and ideas and allow time for the water utilities to develop new supply or operating parameters in time to meet demand. Careful future planning has ensured and uninterrupted water supply though several significant droughts.

The 2010 Washington Metropolitan Area Water Supply Reliability Study -Demand and Resource Availability for the Year 2040 was done as two studies. The 2010 study estimates that water demand in the Washington Metropolitan region will rise from its current level of approximately 500 million gallons per day to between 610 and 665 million gallons a day by the year 2040. Over this same period, population in this area is projected to increase from 4.2 million to 5.3 million.

According to that portion of the study, the Washington Metropolitan Area’s current water supply system will likely meet demands through the year 2030, under a range of hydrologic conditions similar to those experienced during the past 78-year period of historical record. However by the year 2040, the current system may have difficulty meeting the region’s demands during periods of severe drought without emergency water use restrictions, and/or the development of additional supply resources.

The key assumption for that report was that the future flow of the Potomac River will mirror the hydraulic conditions for the past 78 years. If hydraulic conditions are changing or a 78 year period is inadequate to predict the possible extent of droughts, this could impact the availability of water. So the ICPRB engaged a study for various climate scenarios of water supply availability from Potomac Watershed to determine if the water supply would be adequate to serve the population. The National Research Program of the U.S. Geological Survey (USGS) actually performed the study using six of the global climate models and three atmospheric CO2 scenarios to create 18 separate possible scenarios. The USGS then “downscaled” the 18 global climate predictions to the Potomac River basin and to other areas as part of a separate project on climate change being conducted by the Chesapeake Bay Program Office and the USGS’s Virginia Water Science Center (your tax dollars at work). In addition, the Chesapeake Bay Program’s Phase 5 Watershed Model was used to estimate the impact of changing temperatures and precipitation on Potomac basin stream flows.

There is tremendous uncertainty in projecting the future climate of the earth, especially at the regional scale. Though global climate models are continually being refined and improved, they do not capture complexity of the interrelations of earth’s land, water, and atmospheric systems that we do not yet fully understand. Local nuisances can be lost in the broad sweeps of mathematical modeling of a living system. Scientific confidence in global model projections is higher for temperature than for precipitation, higher for global scales rather than small regional scales, and higher for longer time frames than shorter ones.

Though the modelers have always claimed greater accuracy for temperature forecasts than precipitation, they have not done a good job of forecasting surface temperature for the past decade. The average surface temperature of earth has actually not increased in the past decade and none of the climate models have been able to adequately explain that anomaly. For the period of 1970 to 2000 the median surface temperature as recorded by measurements increased 0.3 ± 0.04°F per year. However, there has been little further warming of the surface of the planet, particularly over the oceans in the most recent 10 to 15 years. Nonetheless, with all those disclaimers, the USGS did get some predictions out of their 18 scenarios.

Results for the 18 climate scenarios fell into three categories: minor impact, moderate impact, and major impact. The biggest impact is the ability of the regional water utilities to continue to supply water on demand during droughts as the climate changes (or not). Six of the scenarios are predicted to have little impact on the system during a moderate drought and the projected population of the region can be supplied with drinking water from the Potomac River and current systems and operations. Six of the climate change scenarios fall into the “moderate impact” category. Under these scenarios the region is predicted to experience more frequent and stricter water use restrictions, but no water supply shortages during a moderate drought. Reservoir levels are predicted to fall to significantly lower levels during a drought than would occur in the absence of climate change with the projected and assumed increase in population.

Water Stays On In Prince George County

From Middlesex County

Last Thursday sensors that had just recently been installed on a water main began hearing the pings they were listening for indicating an imminent failure of a concrete water main in Prince Georges County. Washington Suburban Sanitary Commission, WSSC, immediately planned a shut-down and replacement of the section of piping that began Tuesday evening. WSSC announced that water in the affected area of Prince George’s County was expected to be out for several days as the concrete water main is replaced with a more durable steel pipe because the nearest valve that would have limited the shutdown had failed. However, two WSSC employees were able to repair the 48 year old valve in place and the repair held. Diminished water supply remains in Southwest Prince George County. Mandatory water restrictions remain in place for the area to preserve the reduced water supply to the system. WSSC had warned the public that there would be no water for up to 5 days. Though it was responsible to warn the public of that possibility, especially after the valve failures during the fourth of July water main replacement in 2010, they have impaired their credibility for future warnings.

This shut down is how the sensor system that cost more than $21 million over the past six years is supposed to work. If you will recall, one of these massive water mains in the WSSC system exploded back in March in Chevy Chase without warning despite sensors being present in that section of piping. According to the Washington Post the March 18, 2013 pipe explosion created a 50-by-70-foot crater in Chevy Chase Lake Drive and adjacent stream bank, and the lack of warning was because the failure occurred in a joint. In  2010 a water main needed to be replaced over the fourth of July weekend forcing water restrictions on Montgomery and Prince George counties as the replacement did not go smoothly due to valve failures. In addition, in late 2008, a concrete main 66 inches in diameter burst in Bethesda, causing a torrent of frigid water that stranded cars and drivers. Other large water-main breaks in the past several years have led to advisories to boil-water for homes, businesses and hospitals as well as the temporary closure of schools and day-care centers.

The WSSC has approximately 350 miles of concrete mains designed to carry high volumes of pressurized water. These concrete water mains came into use in the United States and other nations in the late 1950’s and continued in use for water systems into the mid 1970’s when they were found to suffer from early failures. Water systems are built by the lowest bid contractor. During the rapid growth during the 1960’s concrete pipes reinforced and wrapped with steel wire were the least expensive method to build out the water infrastructure in the rapidly expanding communities, and the only option at the time for the largest diameter pipes.

This type of steel reinforced concrete pipe has failed catastrophically across the nation decades before their promised 100-year life expectancy would have predicted. Though the actual failure rate is still small at fewer than 1,000 known incidents in the 28,000 miles of this type of pipe installed nationwide, it is expected to increase as these pipes age. Unfortunately, WSSC has the second largest number of miles of this type of piping in the nation. In addition, the low-bidder supplier, Interpace, may have produced inferior pipe- most of the recorded failures of this type of pipe were in the Class IV wire Pre-stressed Concrete Cylinder pipe manufactured by Interpace. The company was successfully sued by WSSC and others and is now out of business. Nine of the WSSC’s concrete mains have blown apart since 1996.

The large diameter concrete pipes are the trunk lines or backbone of the WSSC’s 5,600-mile water distribution system for Montgomery’s and Prince George’s counties. The large transmission mains carry water from the treatment plants and feed the smaller pipes that reach into neighborhoods, homes and businesses. The pressure in the mains keeps the water pure and flowing. WSSC estimated that it would cost $2.9 billion to replace all 350 miles of large diameter concrete mains and instead they installed the sensor system to warn of an imminent rupture.

Fairfax Water has 109 miles of concrete pipe and has experienced 3 breaks since 1996. Only a small fraction of their concrete pipe is the large diameter pipe supplied by Interpace. Fairfax Water replaced about five miles of concrete Interpace pipe a decade ago. Moreover, most of Fairfax Water’s concrete mains are three feet in diameter or less. Not only would failure would be far less catastrophic, but the smaller pipes have experienced less failure.

In June, the U.S. Environmental Protection Agency (EPA) released the results of their 2011 Drinking Water Infrastructure Needs Survey and Assessment. The survey showed that $384 billion in improvements are needed for the nation’s drinking water infrastructure through 2030 for systems to continue providing safe drinking water to 297 million Americans 24 hours a day 7days a week. That estimate only covers infrastructure needs to maintain current systems and excludes costs for raw water supply (dams and reservoirs), water system expansions necessary for population growth, and water system operation and maintenance costs. These costs are not included in the EPA estimate, but do appear as part of the estimates of the American Water Works Association, AWWA, who estimated that the cost would be significantly higher than the EPA estimate, and could top $1 trillion. In addition, AWWA believes that WSSC may have the largest problem of failed Class IV wire Pre-stressed Concrete Cylinder pipes in the nation, but certainly in the east. We can not take for granted 24/7 water, sewer and electricity, or we will not have them.

Prince William County the Retirement Mecca that will Survive Climate Change

The climate of the earth is constantly changing. Scientific studies have indicated that over the past century the earth has warmed 1.3 degrees Fahrenheit. This warming is not particularly alarming in itself given our planetary history, but the speed of this temperature increase and the fact that the warming is projected to continue at an accelerated pace is worrisome. The planetary warming is forecast to cause sea levels to rise due to melting of sea ice in parts of the world, and changes in weather and patterns and precipitation. If carbon dioxide (CO2) concentrations in the atmosphere are the driving force in earth’s temperature that many scientists believe, then these trends are likely to continue. On a whole earth basis the climate models show at this point there is nothing that we can do to stop global warming and climate change.

As the concentrations of CO2 in the atmosphere increase, the warming produced by the greenhouse gas effect is strengthened. Computer modeling of the climate predicts that there will be feedbacks that significantly increase the impact from the increasing CO2. Even if the concentration of CO2 in the earth’s atmosphere were to stabilize at this level, the changes in the climate of the earth in response to the atmospheric CO2 levels would continue for hundreds of years. In reality, the global emissions of CO2 will not stabilize or decrease any time soon and will continue to rise for at least a generation. What is going to happen will happen, so we need to plan for change and make decisions for the next 30-50 years based on likely outcomes.

It is my plan to live for another 40 years. My relatives do pretty well and I am an optimist and a “real food” and exercise devotee. So when it came time to select a place to live in retirement, climate change was one of the factors taken into consideration- water availability, distance from the coast, elevation, along with proximity to family, medical service and an airport and several other factors. Now, I find myself in northwest Prince William County a place that the Washington Post recently described as becoming “a regional retirement mecca, a small-scale version of Florida on the outskirts of Washington.” I made my choices based to a large extent on general projections of climate released by various groups, not having the tools or resources to do much more.

Now, however, the Interstate Commission on the Potomac River Basin (ICPRB) has completed a study in water supply availability and the health of the Potomac Watershed for various climate scenarios. The focus of their study was the Potomac River, which supplies water to the Washington Aqueduct, Washington Suburban Sanitary Commission (WSSC), and Fairfax Water who all funded the study. The Potomac River supplies 78% of the regions drinking water and the water utilities of the region must plan for the future. In addition, there must be adequate flow of the Potomac below Little Falls to ensure that the balance of saline and fresh water for the health of the Chesapeake Bay estuary. So, on the water rate payer’s nickel I get to see what the future might look like here in in Prince William County.

The National Research Program of the U.S. Geological Survey (USGS) actually performed the study using six of the global climate models and three atmospheric CO2 scenarios to create 18 separate possible scenarios. The USGS then “downscaled” the 18 global climate predictions to the Potomac River basin and to other areas as part of a separate project on climate change being conducted by the Chesapeake Bay Program Office and the USGS’s Virginia Water Science Center (your tax dollars at work). In addition, the Chesapeake Bay Program’s Phase 5 Watershed Model was used to estimate the impact of changing temperatures and precipitation on Potomac basin stream flows.

The most advanced types of models currently being used to project future global climate are general circulation models (GCMs). A GCM is a numerical model which represents the important physical, chemical, and biological processes on the Earth’s surface, in the atmosphere, and/or in oceanic systems that affect climate. The USGS used models from the National Center for Atmospheric Research (USA), Norway, Australia, Russia and Japan as listed in the chart below.

From ICPRB publication

In addition, the three CO2 emissions scenarios were based on IPCC’s Climate Change 2007: Synthesis Report (IPCC, 2007c). The USGS used relatively low emissions (B1), medium emissions (A1B), and high emissions (A2) temperature forecasts for each model to create the 18 scenarios.

IPCC Climate Change 2007

There is tremendous uncertainty in projecting the future climate of the earth, especially at the regional scale. Though global climate models are continually being refined and improved, they do not capture complexity of the interrelations of earth’s land, water, and atmospheric systems that we do not yet fully understand. Local nuisances can be lost in the broad sweeps of mathematical modeling of a living system. Scientific confidence in global model projections is higher for temperature than for precipitation, higher for global scales rather than small regional scales, and higher for longer time frames than shorter ones. Nonetheless, with all those disclaimers, the USGS did get some predictions out of their 18 scenarios.

Though it is predicted by the climate models that precipitation will increase on a global scale, when dealing with only the Potomac River basin, the models differed on whether precipitation will increase or decrease. The models project that the total annual precipitation varies from plus 9% to minus 9% or that the rainfall/ snowmelt that averaged 42.2 inches during the reference period (1988-1999) may stay within 4 inches of that average. Though, it is to be noted, that year to year weather variations in rainfall in the region are large, precipitation has varied from over 80 inches to below 20 inches in the past. Also, in the 18 climate scenarios, the increase in annual average temperature by 2040 increases for the area from 1.3 to 4.1 degrees Fahrenheit when compared with the reference period of 1988 to 1999. The average increase, over all scenarios is 2.7 degrees Fahrenheit. (These temperature predictions were the basis of the energy savings and water savings projects for my home that were geared for a slightly warmer, drier climate, though I am still hoping for wetter.)

Though annual rainfall increases in half of the climate change scenarios, flow in the Potomac River falls in most scenarios. Changes in both temperature and precipitation affect stream flows. Changes in rain or snow affect the amount of water that runs off the land surface and enters streams during rainfall. Precipitation also affects the amount of water recharging groundwater aquifers, which are the primary source of stream flow during dry weather periods. Increasing temperatures will cause more rain to be lost to evaporation from the soil, streams, and will increase transpiration, the water released to the atmosphere by plants. These increases in evaporation and transpiration will tend to reduce flow in streams which in turn reduces flow in the Potomac. With rising population, this could require changes in water use and supply for the area and reduce groundwater availability for private well owners like me.

Average annual basin-wide evaporation and transpiration is predicted to increase by 6-8%. Groundwater recharge decreases under all but three of the climate scenarios, and as I watch the statistically low water level in the monitoring well up the road, I worry about my well water supply. According to study results, the seasonal pattern of groundwater recharge does not change significantly under climate change, with January, February, and March remaining the months of greatest recharge. However, the average annual amount of groundwater that provides base flow to streams and the water in my well, is predicted to decrease in 16 out of the 18 scenarios by as much as 34% in one case.

Results for the 18 climate scenarios fell into three categories: minor impact, moderate impact, and major impact. The biggest impact is the ability of the regional water utilities to continue to supply water on demand during droughts as the climate changes. Six of the scenarios are predicted to have little impact on the system during a moderate drought and the projected population of the region can be supplied with drinking water from the Potomac River and current systems and operations. Six of the climate change scenarios fall into the “moderate impact” category. Under these scenarios the region is predicted to experience more frequent and stricter water use restrictions, but no water supply shortages during a moderate drought. Reservoir levels are predicted to fall to significantly lower levels during a drought than would occur in the absence of climate change with the projected and assumed increase in population.

However, the remaining six climate change scenarios are scary. Under these dreadful six scenarios, unless we make changes in the water supply systems we run out of water. These scenarios predict that both mandatory and emergency water use restrictions would be imposed and most system reservoirs would become empty or close to empty during a moderate drought. In addition, these six scenarios predict on some days of the drought the Potomac River would fail to provide sufficient water to meet demand and environmental needs. Our regional water utilities: The Washington Aqueduct, Washington Suburban Sanitary Commission (WSSC), and Fairfax Water working together with the ICPRB can make changes to the structure and operation of the water supply system to make it more robust. The Potomac River will continue to supply water to the region, we will have to use it more wisely to ensure adequate water supply in the future, but there will be water.  Clearly though, development in the groundwater recharge zones (mostly the Rural Crescent in Prince William County) and open areas needs to be limited to protect the groundwater and stream base flow that supplies our water.