Millions of gallons of untreated sewage released in Greensboro in 2018

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Lake Higgins (City of Greensboro)

Untreated sewage discharges increased significantly in Greensboro in 2018, releasing more than 3.5 million gallons of untreated sewage into communities. Blockages, old infrastructure and increased rain from climate change pose risks to the city’s sewer system.

In 2018, Greensboro sewer lines released more than 3.5 million gallons of untreated sewage onto roads and, often, into waterways. The city experienced 64 untreated sewage discharges, otherwise known as sanitary sewer overflows or SSOs that year. So far this year, the city has experienced 13 SSOs — 10 in January and three in February — amounting to more than 21,000 gallons.

The largest overflows in 2018 occurred in September and October when Hurricane Florence and Michael dumped massive rainfall over the Carolinas. Combined, the hurricanes caused more than three million gallons of untreated sewage to overflow in the city.

According to the EPA website, SSOs can “contaminate our waters, causing serious water quality problems, and back-up into homes, causing property damage and threatening public health.”

The agency estimates that there are at least “23,000 to 75,000 SSOs per year” in the United States.

Based on a 2013 report card by the American Society of Civil Engineers, the oldest national engineering society in the country, North Carolina scored a C on wastewater infrastructure. The country as a whole, scored a D+ in the same category in 2017.

“North Carolina has documented a need of over $4 billion of additional wastewater infrastructure investment needs through the year 2030,” the report stated. “These funds are needed to replace aging facilities, comply with mandated Clean Water Act regulations, and provide as well as keep pace with economic development.”

The report found that at least $271 billion would be needed to “meet current and future demands” for the country’s wastewater infrastructure.

There are more than 1,600 miles of sewer lines and close to 40,000 manholes in Greensboro, according to city data. The 64 incidents and 3.5 million gallons of discharges in 2018 were an increase from 51 discharges and 91,000 gallons in 2017 and 41 discharges and 794,000 gallons in 2016. Similarly sized cities like Winston-Salem and Durham had 65 and 24 spills respectively during the 2017-2018 fiscal year.

A graph provided by the city however, shows a downward trend in sewer overflows per 100 miles of line since 2011.

Almost a quarter of the discharges in 2018 in Greensboro were caused by grease build-up in the lines. Debris and roots were the second and third most frequent causes.

“On Battleground Avenue where we have a lot of businesses that have services, it can produce grease,” says Mike Borchers, the assistant director of Greensboro’s water resources department. “Sometimes the grease traps don’t work or aren’t maintained properly. The grease can clog up the line and when it gets into the system, it can congeal. It comes from homes too. That’s why we tell people not to dump grease down drains.”

Grease buildup in sewer lines (courtesy photo)

Borchers says that most of the time the discharges come out of manholes and spill out into the street. State law requires overflows of more than 1,000 gallons to be reported within 24 hours and for overflows that reach water sources like rivers, streams or surface water to be reported within 24 hours, regardless of volume. Each report includes items like the number of gallons released, location, date, cause of discharge and waterways affected. The equipment used to treat the discharge as well as the result is also included.

According to Borchers, employees respond quickly to reports of sewage discharge and address the problem immediately. If there is build-up in the lines, they use a jet to clean it out and will wash the surrounding area and put lime down to disinfect. In instances where sewage enters a waterway, employees will “flush” the creek by adding more water to dilute it as it flows downstream.

Many of the reports include the North and South Buffalo tributaries as affected waterways. Both feed into the Cape Fear River which starts near the county line between Lee and Chatham county and flows southeast all the way to the Atlantic Ocean at Wilmington.

A 1998 EPA report found that 40 percent of waterways monitored by states were impaired by contaminants typically found in sewage. While the cause was not concrete, the report found SSOs to be a possible contributing factor.

Other environmental impacts of sewage include hypoxia, or decreased oxygen in water, algal blooms, habitat degradation and impacts to wildlife.

Raw sewage contains disease-causing pathogens, including viruses, bacteria, worms and protozoa and can cause illnesses like the stomach flu and even life-threatening illnesses like cholera and dysentery, according to the EPA. The agency lists ways in which people can be exposed to raw sewage including from drinking water sources, direct contact with areas like basements, lawns or streets, and through eating contaminated shellfish.

A 2006 study published in Environmental Health Perspectives found that there was an association between SSO events and ER visits for GI illnesses in northeastern Massachusetts.

However, Borchers says the likelihood of residents getting sick from these discharges is minimal.

“The good news for us is that we are at the headwaters,” Borchers says. “That means that the Cape Fear River Basin starts up here in Guilford County. SSOs in most cases, won’t go into our lakes.”

Greensboro gets its drinking water from Lake Townsend, Lake Higgins and Lake Brandt. When SSOs enter lakes, Borchers says the city works quickly to isolate the area and then treat it.

In a few instances in 2016 and 2018, contractors working on the lines accidentally broke the pipes, causing thousands of gallons of sewage to enter creeks that flowed downstream to Burlington. In these events, Borchers says they make sure to contact their neighbor right away.

Eric Davis, the water and sewer operations manager for Burlington says they never really saw an impact from the discharges because the amounts are so small compared to the volume of the streams.

Instead, Davis points to the increased amounts of rain that can impact water quality and cause SSOs.

2018 untreated sewage discharge events in Greensboro (Sayaka Matsuoka)

During mid-September last year, more than two million gallons of untreated sewage were released in Greensboro when Hurricane Florence overwhelmed sewer systems. The next month, Hurricane Michael caused another million to be released.

Due to the increasing effects of climate change, scientists predict that both overall precipitation and amount of rain in heavy downpours will continue to increase in the US. According to data from the Applied Climate Information System, North Carolina has seen an almost 30 percent increase in heavy downpours since 1950.

Inflow — which is caused by excessive rain like the instances caused by hurricanes — and pipe failure accounted for approximately 14 percent of the discharges last year. According to the city, the average age for Greensboro’s sewer line is 39 years compared to the country average which is 33. Some of the lines in the city, however, are close to 100 years old. The composition of the lines also varies. The newer ones, Borchers notes, are made from iron but older laterals, or those that connect houses to the street lines, are made of terra cotta or clay. These are more susceptible to breaks which can cause SSOs.

“The clay can crack because the tree needs moisture,” Borchers explains. “The root system will migrate to where the water source is.”

In addition to fixing and cleaning the lines when there is an incident, Borchers says the city schedules preventative maintenance on its lines and actively rehabilitates old or problem ones.

“We try to get up to one percent of our system year over year,” Borchers says. “Doing one percent, hopefully we’ll touch all the lines over a 100-year period. We’re fixing lines that have met their life expectancy or are overworked.”

According to city data, in 2018, 48,421 feet or a little more than 9 miles of sewer lines were rehabilitated at a cost of $5,021,048. This amounts to just .56 percent of the city’s lines, falling short of the yearly one percent goal.

Most of the money to repair and upgrade the pipes comes from residents’ water utility bills, Borchers says. The department has a $120 million budget each year. He also says that there are several active and open revenue bonds totaling close to $260 million to help subsidize the repairs and upgrades.

“We try to be as proactive as we can,” Borchers says. “Our goal is not to have any SSOs. It’s not our intention nor do we want them. We want to thank our customers for their patience and understanding as we move forward to address these issues.”

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