Water and Sewage in Loudoun County

In the past generation Loudoun County has grown from a predominantly rural area with a few small towns like Middleburg, and Leesburg to a booming high density suburb. The population has exploded to an estimated 336,000 in 2013. With people comes human waste-sewage. Under the terms of an agreement dating back to the first development of the Dulles Airport area the sewage from Loudoun County that was not handled by private septic systems was pumped to be treated by the District of Columbia’s sewage treatment plant.

The District of Columbia's sewage system, one of the oldest in the United States is located on the southernmost tip of Washington DC and called the Blue Plains Advanced Wastewater Treatment Plant. While there are larger sewer treatment plants, that remove the solids and bacteria, the modern day Blue Plains also has Tertiary Treatment to remove nitrogen and phosphorus making Blue Plains the largest advance treatment plant in the United States. The plant sits on 150 acres and has a rated average daily capacity if 370 million gallons per day and a peak wet weather capacity of 1,076 million gallons a day. The system needs such a large storm rated capacity to accommodate the old central city combined sewer system that overflows with predictable regularity during large storms. Blue Plains is under a consent order from the Environmental Protection Agency, EPA, to meet new effluent limits for total nitrogen released and better control of the system during storms.

These problems and distance limited the long term ability of Blue Plains to treat waste water from Loudoun County. Today, 13.8 million gallons per day of the wastewater Loudoun County Service Authority (Loudoun Water) collects from the sewer system gets treated at Blue Plains Treatment Plant. Though that is still most of the waste water, Loudoun Water began treating waste water in Loudoun County in 2008. This was carefully tested and studied because Loudoun Water’s discharge is upstream of the of drinking water intakes for the three major Washington area water utilities, Washington Aqueduct, Fairfax Water, and Washington Suburban Sanitary Commission. These utilities serve over three million people in the Washington, D.C. region. While sewage treatment discharges upstream of drinking water intakes are not uncommon in Virginia, a more stringent set of regulations were developed for the Washington D.C. metropolitan area drinking water supplies. The goal of the regulation is to provide an even higher level of assurance that the drinking water supply for the millions of regional residents is protected. The Dulles Watershed Regulation specifies:

• The number of sewage treatment plants is limited to two and ownership is specified;
• The two sewage treatment plants must be a minimum of 10 miles upstream of a drinking water intake or proposed intake;
• The effluent limitations are very stringent, far exceeding what might otherwise be required to protect water quality standards and exceeding effluent standards that have been achieved elsewhere. 

Loudoun Water began planning more than a decade ahead of the need and were able to work with Virginia Tech‘s Department of Civil and Environmental Engineering, the Occoquan Watershed Monitoring Laboratory, to develop a treatment strategy and pilot the program to demonstrate its effectiveness. Loudoun Water staff and its consulting team presented their findings in May, 2001.

After demonstration of the technology, Loudoun Water built the Broad Run Water Reclamation Facility (Broad Run), a state-of-the-art plant that treats wastewater to the limits of today’s technology. In 2008, Loudoun Water began collecting more wastewater than they could send to Blue Plains, and the Broad Run plant went on-line on May 2, 2008, meeting permit requirements on the very first day. The facility discharges to Broad Run, a tributary to the Potomac River, can treat up to 11 million gallons a day and has demonstrated the waste water technology of the future as well as a water resource management strategy emphasizing water reuse.

From Loudoun Water web site- Broad Run

The Broad Run plant uses preliminary screening/grit removal, primary clarification, fine screening (2 mm), flow equalization, a membrane bioreactor, and activated carbon and UV disinfection. The membrane bioreactors are dispersed in twelve membrane tanks. Membrane filtration eliminates the need for clarifiers and settling tanks, and results in improved water quality that enables water reuse. The first water reuse projects in the county have been completed. So far Loudoun Water has installed over 30,000 feet of reclaimed water pipe called “purple pipe” to two data centers and the National Rural Utilities Cooperative Finance Corporation located along Route 28. These customers receive reclaimed water for irrigation, cooling towers and other non-potable uses, in order to meet LEED (Leadership in Environmental and Energy Design) criteria and other environmental and economic goals (recycled water is cheaper). Waste activated sludge from the Broad Run plant is centrifuge thickened, combined with primary sludge for stabilization in anaerobic digesters, and centrifuge dewatered prior to land application. Loudoun Water is proactively planning for the future of their region.

There are sections of Loudoun County that are not served by Loudoun Water. These area are either served by private well and septic system or community systems. As Loudoun County was expanding, developers began building free standing Community Water and Wastewater Systems. These systems provide water to a rural development, village or hamlet and may also provide wastewater treatment utilizing what is called a packaged treatment facility. Treated wastewater is discharged either on site (to a drip irrigation field) or to local streams and rivers. These packaged systems are limited and have a permitted capacity of about 170 gallons per day of waste water per house that should not be exceeded. Loudoun County's Comprehensive General Plan does not allow central water and sewage service into the Rural Policy Area. To get this changed would require a Comprehensive Plan Amendment (CPAM).

The Report Card on America’s Infrastructure

Every four years the American Society of Civil Engineers, ASCE, grades the infrastructure in the United States, from water mains, sewer systems and plants, power lines connected to homes and businesses and the electrical grid spanning the U.S.; the neighborhood streets and the national highway system, dams, rail roads, airports. Infrastructure is the foundation of our economy, connecting businesses, communities, and people, making us a first world country. For the U.S. economy to be competitive as a place of business, we need a first class infrastructure system – transportation systems that move people and goods efficiently and at reasonable cost by land, water, and air; transmission systems that deliver reliable, low-cost power from a wide range of energy sources; and water systems that deliver clean reliable water 24/7 and remove wastewater for treatment and often reuse.

Yet much of our nation’s infrastructure was built during the 20th century, expanded during the post-World War II period, and frankly taken for granted by Baby Boomers. For some time our infrastructure systems have failed to keep pace with the current and expanding needs, and investment in infrastructure had faltered as an unseen way to cut costs- until the systems fail. However, it seems the tide has begun to turn. The 2013 Report Card grades are in, and America’s cumulative GPA for infrastructure rose slightly to a D+ from the D we received in 2009. The grades in 2013 ranged from a high of B- for solid waste to a low of D- for inland waterways and levees. Solid waste, drinking water, wastewater, roads, and bridges all saw incremental improvements, and the rail systems due to an influx of private investment jumped from a C- to a C+. No categories saw a decline in grade this year.

Highlights from the national report:

The grade for drinking water improved slightly to a D. In many parts of the nation, much of the piping that delivers water to our homes and businesses is almost a century old, nearing the end of its useful life. There are an estimated 240,000 water main breaks per year in the United States. Assuming every pipe would need to be replaced, the cost over the coming decades could reach more than $1 trillion, according to the American Water Works Association (AWWA), though new technology is being demonstrated to extend the life of older piping systems. The United States still has one of the safest drinking water systems in the world, but in many communities the pace of water main replacement will have to increase. Even though pipes and mains are frequently more than 100 years old and in need of replacement, outbreaks of disease attributable to drinking water are rare because of the good treatment systems and positive pressure on the drinking water distribution systems.

The grade for wastewater improved slightly to a D. The ASCE estimates that $298 billion will be required over the next 20 years to maintain and upgrade the nation’s wastewater and stormwater systems. As in the water delivery systems pipes represent the largest capital need, three quarters of the costs. Fixing and expanding the network of pipes will reduce sanitary sewer overflows, combined sewer overflows, and other pipe-related issues like urban sinkholes. Investment in wastewater treatment plants will have to increase due to new regulatory requirements as the U.S. Environmental Protection Agency, EPA, expands mandated nutrient and sediment management standards and water recycling programs across in the nation. In the past five years EPA regulations have required cities to invest more than $15 billion in new pipes, plants, and equipment to eliminate combined sewer overflows. Stormwater management is still small compared with sanitary pipes and treatment plants, and its growth may be managed by Low Impact and Green Infrastructure strategies. Even with these lower cost strategies, EPA programs like the Chesapeake Bay TMDL will dramatically increase that investment in wastewater infrastructure during the coming decades, but may maintain and improve water quality even with a growing population.

The grade ASCE gave for solid waste was a big bright spot improving in 2013 to a grade of B-, the highest grade for any category. In 2010, Americans generated 250 million tons of trash. Of that, 85 million tons were recycled or composted. This represents a 34% recycling rate, a vast improvement from the 14.5% recycling rate in 1980. Per capita generation rates of waste have been steady over the past 20 years and have declined since 2006. Though there is plenty of room for improvement, a generation raised on “Reduce, Reuse, Recycle,” seems to be having a big impact.

The grade for energy remained at a D+ despite the boom in gas and oil due to weakness in the distribution systems. The weaknesses in the electrical grid were highlighted in the extended outages during the storms that pounded the east coast in the past two years especially in New Jersey and Maryland. Investment in power transmission has increased in recent years, but ongoing permitting issues, weather events, and limited maintenance have contributed to an increasing number of failures and power interruptions. Use of electricity in the U.S, has yet to regain the peak reached in 2007, but the demand for electricity, natural gas, and oil is forecast to increase in the next decades as the population increases and efficiency savings are used up. Though, recent booms in oil and gas production could supply the energy demand, regulation on carbon generation from electrical generation plants requiring replacement of a significant portion of the generation capacity and about 17,000 miles of additional high-voltage transmission lines (to expand the power grid and connect wind power generation farms and large solar power generation installations to the power grid) and significant oil and gas pipelines are needed to meet the demand for power and regulatory mandates.  Growing permitting and siting issues threaten construction of the generation and distribution systems needed.

Railroads are experiencing a resurgence in both freight transportation and passenger service. As a result freight and passenger rail have been investing heavily in their tracks, bridges, and tunnels as well as adding new capacity spending more than $75 billion since 2009. Increasing investment and utilization was highlighted by the purchase of Burlington Northern Santa Fe LLC, the largest U.S. railroad, by Warren Buffett’s Berkshire Hathaway. That company alone spent $400 million on terminals in 2012 while a group of oil and gas pipeline operators, Plains All American Pipeline LP plans to spend about $1 billion on rail depot projects to substitute for stalled pipeline projects to move oil and gas from drilling sites to processing locations. Private investment resulted in the grade for rail moving up to a C+ in 2013.

Much of the transportation infrastructure-bridges, inland waterways, ports, roads, airports are far more visible and have a much higher public awareness of the needs of the systems, but are primarily funded by public monies. The nation’s infrastructure needs a strong representation for budget allocations because it is our future. The maintenance of the power grid and the water treatment and distribution systems have suffered from neglect due to the way that utility rates are calculated from costs. Regulated monopolies that supply electricity, water, sewage have been cutting maintenance capital budgets to cut overhead while maintaining or increasing profits while limiting rate increases.

Virginia’s 2013 report card has not yet been completed. We received an overall grade of D+ in 2009, but I am hopeful that when the new report is complete that we will have improved to match (or crush) the C- that Maryland received.  Maryland’s report card appears below. 

ASCE report card

Sinkholes In America

According to the Infrastructure Report Card from the American Society of Civil Engineers, New York’s waste water infrastructure needs an investment of $21.82 billion over the next 20 years to avoid failure. Just to emphasize the point in Bay Ridge Brooklyn not far from where I once lived in the 1970’s, the street suddenly caved in on August 1st and a 30 foot wide, 10 foot deep sinkhole appeared. This was the second sinkhole in this neighborhood of Brooklyn this year. The earlier sinkhole was twice as large. The city of New York immediately began repairs. According to the City, the sinkhole was caused by a 112 year old sewer pipe that gave way and washed away the soil under the road. The sewer pipe had no doubt been failing for a long time to erode that much soil.

Picture by CBS 2 Bay Ridge, Brooklyn sinkhole

The pipes made early in the 20th century were rated for an 80 year life span. New York sewer piping systems have reached the end of their design lives, but there are no plans of a replacement and upgrade of the system. There has been no systematic replacement program. New York has kept the sewer system alive by repairing what breaks after it breaks and spraying it’s mains with concrete. When the sewer systems were built in the 19th and 20th centuries, the Boroughs of New York still had autonomy and financed and built their own systems to address the problem in the least expensive way, by using a combined storm and sanitary sewer system. The Manhattan and Brooklyn systems were built around the same time modeling the designs of Hamburg, Germany. Nonetheless, the sewers were never designed for the ages, they need to be maintained and upgraded. New York and most of the United States has not maintained and upgraded our sewer systems. According to the U.S. Environmental Protection Agency, EPA, by 2020 half the sewer pipes in the U.S. will be crumbling and the U.S. risks reversing public health, and environmental gains of the past three decades.(Rose George in The Big Necessity, The Unmentionable World of Human Waste and Why it Matters.)

Failing sewer pipes can pose a significant threat to public health and the environment.  Systems with inadequate hydraulic capacity and/or blockages in the sewer pipes may lead to sanitary sewer overflows and sewage backing up into homes or onto streets.  Some of the health hazards associated with basement flooding by untreated wastewater include the potential presence of pathogenic microorganisms such as viruses, bacteria, and protozoa (in a nice moist dark environment). Pipe failures can be grouped into three general categories: hydraulic restrictions (e.g. blockage), hydraulic capacity, and structural condition.

Hydraulic restrictions are the most common problem in wastewater collection systems. Untreated wastewater carries sediment, grease, rags and whatever else you can think to put down the drain or flush down the toilet. The grease congeals with sediment and blockages form. In combined sewers, large items thrown or washed into the storm system create obstructions and restrictions during peak flow times. This can lead to street and basement flooding. Tree root intrusion, sediment accumulation, and grease build-up all contribute to hydraulic restrictions. Aging pipes that sag over time and joints that begin to fail can slow pipe flow and create more favorable conditions for solids to build up in pipes. An ongoing maintenance program for cleaning and flushing sewers is typically adequate to control blockages. However, budgeting for routine preventative maintenance and repairs has not taken place in New York or the rest of the United States. We fix it when it breaks.

Failure caused by inadequate flow capacity is common in combined sewer systems, but may also a sign of other types of problems such as structural defects or design defects. Major sources of pipe structural defects are cracks, broken pipes, and leaks. Pipes sag and sewage does not flow properly, areas of inadequate pipe slope can be due to loss of pipe bedding or inadequate initial slope. Structural failure as in Bay Ridge is typically caused by defects of the pipe wall and/or the soil envelope used to support the pipe.

The EPA reported that the total investment needs of America's publicly owned treatment works as of January 1, 2004, was $202.5 billion and increasing each year. Many systems besides New York have reached the end of their useful design lives, and the nation’s wastewater systems are no longer resilient in their ability to prevent failure, or restore service after a disruption. In addition, the electrical generation and distribution system, the energy sector, contributes to the lack of system’s resilience. Pumps and wastewater treatment plants do not operate without power and reduced reliability of the power supply is increasingly being addressed through the construction of dedicated emergency power generation at wastewater treatment plants and drinking water delivery systems.  Clean and safe water should be the national priority. If we had spent even a quarter of the  $821 billion of the American Recovery and Reinvestment Act of 2009 on the very unglamorous sewers and water treatment systems if the country we would have a cleaner environment, part of our infrastructure would be ready for another century and construction workers would have had jobs.