Spring- Time to Flush the Pipes

 As part of the annual maintenance program for the regional water distribution systems in Virginia and Washington DC, on March 21st , 2022 Fairfax Water, the Washington Aqueduct, Loudoun Water and the City of Manassas will switch from chloramine to chlorine to disinfect their water. During this time, Arlington Department of Environmental Services, DC Water, the Prince William Service Authority, Loudoun Water and Fairfax Water will begin flushing their water distribution systems. Each spring these water distribution companies flush their water mains by opening fire hydrants and allowing them to flow freely for a short period of time.

Fairfax Water will disinfect with chlorine from March 21st  to June 13th and the water systems the flushing of the water mains in Fairfax and Prince William will occur during that time. Crews from the Service Authority and Fairfax Water will open hydrants throughout their service area in brief intervals in order to draw water more forcefully through the distribution system and scrub out the pipes. This helps to dislodge sediment that may have collected in water mains over the past year. In DC, Arlington and  Falls Church, the flushing will occur from March 23 through May 9th , 2022. Those jurisdictions purchase treated drinking water from the Washington Aqueduct. Loudoun Water also announced they will be starting their program on March 21st.

For most of the year, chloramines, also known as combined chlorine, is added to the water as the primary disinfectant. During the spring the water treatment plants for Fairfax Water, Loudoun Water and the Washington Aqueduct switch back to chlorine in an uncombined state, commonly referred to as free chlorine. This free chlorine reacts with sediments suspended during flushing and kills bacteria that may be in the bio-film that forms on the pipe walls. Many water chemistry experts believe this short exposure to a different type of disinfectant maintains a low microbial growth in the bio-film and improves the quality and safety of the water.

This change in disinfection is an annual program to clean the water distribution pipes and maintain high water quality throughout the year. The U.S. Army Corps of Engineers Washington Aqueduct provides water to the District of Columbia, Arlington County, and other areas in Virginia. Fairfax Water provides water to Fairfax County and parts of both Loudoun and Prince William County. WSSC does not switch their disinfectant.

You may notice a slight chlorine taste and smell in your drinking water during this time, this is not harmful and the water remains safe to drink. Depending on your location within the distribution system, it could take up to a week for your drinking water to transition from combined to free chlorine at the beginning of the flushing program, or from free chlorine to combined chlorine at the conclusion of the flushing program. You may want to use filtered water to drink or leave an open container of water in the refrigerator for a couple of hours to allow the smell to dissipate. Refrigerator filters remove chlorine so you do not have to worry about ice. Water customers who normally take special precautions to remove chloramine from tap water, such as dialysis centers, medical facilities and aquarium owners, should continue to take the same precautions during the temporary switch to chlorine. Most methods for removing chloramine from tap water are effective in removing chlorine. The annual chlorination is important step to remove residue from the water distribution system. Free chlorine is better suited to remove residue that may have collected in the pipes than chloramine and a coordinated opening of fire hydrants serves to flush the system and scrub the pipes.

WSSC, Winter and Water Main Breaks

 

Water main breaks can leave hundreds of people without service and can also cause serious traffic problems, making the daily commutes even more challenging. WSSC takes winter preparations very seriously; however, every time there is a cold snap the number of water breaks and leaks increases. There is a direct connection between dropping water temperatures in the Potomac River and the increase in water main breaks. In the chart above you can see the response to temperature changes in the increase or decrease in water main breaks. 

According to the WSSC, they typically see an increase in water main breaks a few days after the Potomac River temperature hits a new low. The dropping water temperature can “shock” water mains, and though the pipes become accustomed to the cold water; whenever water temperatures hit a new low, there is a spike in breaks. Aging pipes is also a critical factor in breaks and leaks. The older, often brittle pipes are “shocked” by the colder water, causing them to break. Approximately 40% of the water mains in WSSC Water’s systems are more than 50 years old.

When the temperature drops the incidence of water main breaks rise. There are approximately 5,800 miles of water mains in the WSSC distribution system. On average, WSSC crews repair more than 1,800 water main breaks and leaks each year, with the vast majority of them, approximately 1,100, occurring between November and February. January 2018, the year the polar vortex hit our region had the most repairs of any month on record, 802 water mains were repaired in January alone. You can see the surge in water breaks that year in the chart below along with the seasonal pattern. 

  

The weather has snapped cold again. WSSC requests lease report water main breaks or leaks anytime 24/7 by calling 301.206.4002 or by email at EmergencyCallCenter@wsscwater.com. DC Water reports that they average between 400 and 500 water main breaks per year. Fairfax Water does not post their average total annual leaks and breaks, but has a live interactive site listing all current leaks. To report a leak Contact Us | Fairfax Water - Official Website.

 

Polar Vortex Brings Water Main Breaks to WSSC

 

from WSSC

As the chart above shows, there is a direct connection between dropping water temperatures in the Potomac River and the rate of water main breaks. When the temperature drops the incidence of water main breaks rise. The river is the primary source of drinking water for 1.8 million WSSC Water customers in Montgomery and Prince George’s counties. When a new low temperature is reached, the colder water can shock pipes, increasing the number of breaks and leaks a few days later.

On average, WSSC crews repair more than 1,800 water main breaks and leaks each year, with the vast majority of them, approximately 1,200, occurring between November and February. In the chart above you can see the increase number of breaks this past week. WSSC has been working hard to repair breaks. Fortunately, the number of water main breaks has stayed below the record of 2017.

Of the 5,700 miles of water mains in their distribution system, approximately 2,900 miles are cast iron pipe, which were used from 1916 to through 1976. These pipes are more prone to break in cold weather because cast iron is a brittle material and becomes more so after 60 years. Pipe age is a primary factor in the majority of breaks. Nearly 40% of WSSC water mains are more than 50 years old.

Why WSSC Pipes Are Failing

The Washington Suburban Sanitary Commission (WSSC) provides water and sewer service to nearly 1,000 square miles in Prince George’s and Montgomery counties in Maryland. Established in 1918, WSSC is one of the largest water and wastewater utilities in the nation, with a network of nearly 5,600 miles of fresh water pipeline and over 5,400 miles of sewer pipeline. WSSC supplies water and sewer service to 1.8 million residents in approximately 460,000 households and businesses.

In addition to the water and sewer pipeline systems, WSSC operates 3 reservoirs, the Triadelphia, Rocky Gorge, and Little Seneca, that have a total holding capacity of 14 billion gallons. A regional reservoir, the Jennings Randolph Reservoir, holds an additional 13 billion gallons of water is shared with the other two regional water utilities, Fairfax Water and the Washington Aqueduct.

WSSC also operates 2 water filtration and treatment plants – The Patuxent (max 56 million gallons per day and the Potomac (max 285 million gallons a day) plants that together produce an average of 167 million gallons per day of safe drinking water. Despite the recent brown or rust colored water problems reported over the past 6 months in Montgomery County, the water reportedly remains safe if unappealing. The brown water problem is become symbolic of the problems with WSSC. About 15 years ago WSSC ceased flushing the water distribution system with chlorine each spring.

Though WSSC operates 6 wastewater treatment plants – Western Branch, Piscataway, Parkway, Seneca, Damascus, and Hyattstown with a total capacity to handle 71.08 million gallons of wastewater per day, most of their waste water is treated at Blue Plains. The Blue Plains Advanced Wastewater Treatment Plant, operated by DC Water, handles as much as an additional 169 million gallons a day of waste water under a cost sharing agreement with the WSSC, treating on average approximately 65% of WSSC’s wastewater annually.

When WSSC was founded Prince George’s and Montgomery counties were mostly rural. The utility was overseen by the two County Councils. During the 1960s and continuing through the late 1980s, WSSC experienced growth rates that were unprecedented. For most of that time WSSC charged only nominal fees for new customers to join the system instead of the actual cost to run the piping, instead WSSC used debt to finance the expansion of the system. In the mistaken belief that growth and increasing revenues would solve the debt problem. However, by the end of the last century, debt service (principal and interest) on bonds used to finance the system expansion accounted for one-half of WSSC’s total revenues and revenues were falling.

While WSSC was incurring a pile of debt to expand the system, the differences between the commissioners appointed by Prince George’s and Montgomery counties resulted in deadlocked decision-making, preventing the needed investment in repairing, replacing and rehabilitating the oldest parts of WSSC’s water and sewer systems, which were approaching the end of their useful life. WSSC had also lost a class action suit when they tried to impose increased hookup charges and capital charges as a System Expansion Offset Charge. In its 1984 decision, the court found that WSSC did not have the authority to adopt the charge and that the System Expansion Offset Charge as adopted was unreasonable.

Though the General Assembly finally gave WSSC the explicit authority to impose a system expansion charge, but by that time WSSC had already inherited a legacy of debt-financed expansion costs and an operating culture that did not have preventive maintenance and viewed inappropriate cutting of system maintenance and upgrade as cost savings, rather than what they were. No investment in the infrastructure took place unless it broke or was a mandated upgrade by the regulators. The majority of the investment in the systems was spent at the central waste water treatment plants and water treatment plants.

About 15 years ago WSSC went so far as to cut the annual flushing of the water distribution system. Flushing of the water distribution system removes sediments comprised mostly of minerals (including iron and manganese) which have accumulated over time in the pipes. An annual flushing program helps to keep fresh and clear water throughout the distribution system. Removing the residue ensures that when the water arrives in your home, it is the same high quality as when it left the water treatment plant. While these programs continued with Fairfax Water and DC Water, WSSC stopped. The recent increasing occurrence of brown or rust colored water in Montgomery county is probably the result.

WSSC representatives initially claimed the brown water was caused by an increase in the sodium from the winter’s road salt triggered increased leaching of manganese from the soil, into groundwater and then into the Potomac River. Iron and manganese can cause discolored water, but would have been seen in the water exiting the water treatment plant, though reportedly elevated sodium and manganese levels were seen in the finished water, it was within drinking water standards and clear. In addition, neither Fairfax Water nor DC Water customers have been experiencing increased incidences of brown water. If the water was clear leaving the water treatment plant the problem was in the distribution system. Now, WSSC has revised their theory and believes that the salty snowmelt and elevated sodium levels loosened the buildup of rust and manganese in their distribution system. The root cause, the failure to flush the distribution system for years, has caught up with them. Despite the appearance, WSSC reports that the water remains safe if unappealing. This is just one symptom of the problems at WSSC.

WSSC officials say the amount of water pumped, sold and paid for, dropped from a daily average of 130 million gallons in 2004 to 95 million gallons in 2013 due to federally mandated water conservation like low flow toilets and water saving appliances and water awareness brought on by drought. Water consumption which has been the basis of revenue is falling as costs are mounting to upgrade sewer systems and repair and replace aging water pipes and sewer pipes, some more than a century old, that are bursting after decades of decay and neglect. Meanwhile, WSSC’s costs for electricity, chemicals and labor have continued to rise with inflation.

A crisis is brewing because the sustainability of WSSC is eroding. Much of the WSSC’s service areas was built out in the building boom of 1960s and continuing through the late 1980s. The pipes installed in 1960 are 55 years old, in the next decades WSSC will have to replace a significant portion of their piping systems. Over the next 10 years WSSC will have to replace over 2,000 miles of water pipe and similar amount or sewer pipes at an average cost of $1.4 per mile of pipe (2009 WSSC figure) that is almost $6 billion to replace the piping that has exceeded it design life. However, WSSC estimates that they will have to spend about $2.6 billion dollars in the next five years on capital improvement projects and has been studying how to pay for those needs. Issuing more debt and extending the maturities of the existing and future debt to 30 years will simply push their problems down the road a few more years and not develop a plan to renew the water and sewage systems for this century. This is in addition to operating costs, upgrades necessary to water treatment and Blue Plains.

Customers of WSSC might want to consider their own water treatment systems. Chlorination, the oldest method of disinfection can also be used to solve the most vexing problems with minerals. Chlorine will oxidize iron and manganese so they can be filtered out and also oxidize hydrogen sulfide to reduce or eliminate the rotten egg order that can render water here undrinkable. Chlorination followed by a media filter or a rechargeable carbon filter to capture particles and precipitate and the free chlorine can produce pleasant, sanitary water.

It is Not Your Imagination, WSSC Pipe Failure Has Increased

Last Wednesday, August 12, 2015, a 20-inch pressurized sewer main on Rose Theatre Circle in Olney broke causing 270,791 gallons of raw sewage to flow from the pipe and from sewer manholes. Within three and a half hours of the break the Olney Wastewater Pumping Station was shut down to stop the sewage flow so the pipe could be repaired. However, shutting down the Olney Wastewater Pumping Station did not stop the sewage from entering the system and manholes in the area began to overflow with sewage after a couple of hours and did not stop until after the Olney pumping station was put back in service. WSSC brought in septic haulers that were able to prevent approximately an additional 123,425 gallons of sewage from overflowing into the nearby waterways.

This sewage spill may sound a bit familiar, but it is new. What you are recalling is that on Tuesday, July 28, 2015 a different section of the same 20 inch pressurized sewer main began leaking. It was Wednesday morning, July 29th before WSSC stopped the leak and by then about 460,000 gallons of raw sewage had been spilled. Within an hour the same 20 inch sewer 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, July 30th. Now less than 2 weeks later another section of the pipe is leaking.

This is the third break in this sewer 20 inch diameter pressurized sewer pipe in two weeks. Though there were 160 sewer “overflows” in 2014, most of these were caused by blockages in the pipes from grease, tree roots, and debris not pipe failure. Sewer pipe failure, though less frequent cause’s larger spills, this is especially true of sewer pipes that flow under pressure. On Friday WSSC used closed circuit television cameras to examine the pressured sewer main and surprise, it found severe deterioration of the pipe. WSSC has hired a consultant to inspect the condition of the entire main and see if there are more leaks and is planning to develop a comprehensive solution that will eliminate future breaks. WSSC plans to insert a camera inside the pipe to better assess the condition of the sewer main to help determine a long-term solution. After three breaks in the same sewer main, replacing the entire sewer main seems like a sensible long-term solution.

WSSC emphasizes that the water and wastewater systems are separate. The sewage spill will not impact drinking water in anyway. However, the drinking water distribution system is in only slightly better condition than the sewer system. Last Wednesday while dealing with the Olney sewer problem, WSSC had two 90-year-old water main pipes break. The first break, in a 12 inch water main located on East-West Highway at Route 1 in Prince George’s County, was repaired fairly quickly restoring water service to all area customers. The second break in a 10 inch water main, at Flower Avenue and Piney Branch Road in Montgomery County, needed to have Washington Gas fix a gas line before repairs can be completed.

These pipe breaks last week during the summer serve to highlight the issue of aging infrastructure in WSSC’s system. Though, WSSC is currently replacing about 55 miles of water mains per year and 274 miles of sewer pipe over a 12 year period, that is not enough. That rate of pipe replacement would replace the sewer system in 236 years and the water system in 101 years. Pipes do not last that long. WSSC reports that approximately 37% of the water system delivery pipes are over 50 years old. Though age is not the only factor that causes pipe failure, most of the system’s pipes were designed for an average lifespan of 65 years. The break rate for pipes increases after 60 years. Age alone, however, cannot always be used as an indicator of failure, but it is a good predictor in warm weather breaks. There is a relationship between water temperature and pipe breaks. A sudden temperature drop provides a kind of shock to the pipes. Water temperature below 40 degrees Fahrenheit can also cause pipes to become more brittle, and break. That leads to increased pipe breaks in the winter, and why water utilities typically report their February number of breaks- when most breaks take place.

Established in 1918, WSSC is one of the largest water and wastewater utilities in the nation, with a network of nearly 5,600 miles of fresh water pipeline and over 5,400 miles of sewer pipeline. For decades WSSC has deferred maintaining their piping systems, choosing instead to repair pipes as they failed. It is not your imagination, the piping is failing more frequently and is about to get worse. Much of the WSSC’s service areas was built out in the building boom of 1960s and continuing through the late 1980s. The pipes installed in 1960 are 55 years old, in the next decades WSSC will have to replace a significant portion of their piping systems. Over the next 10 years WSSC will have to replace over 2,000 miles of water pipe and similar amount or sewer pipes. WSSC estimates that they will have to spend over $2.6 billion dollars in the next five years on capital improvement projects and has been studying how to pay for those needs.

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.