Responding to Flooded Wells

A sustainability issue

By Charles Job

Hurricane Matthew made landfall in North Carolina on October 8, 2016, with flooding causing massive damage and loss of life in 26 counties of the eastern part of the state.

It also resulted in water wells being flooded and needing service. The North Carolina Ground Water Association, its members, and state and local authorities were available to respond to well owner and groundwater needs for sustainable safe water supplies.

The Storm

Hurricane Matthew dropped more than 15 inches of rain in two days on three counties (Wayne, Sampson, and Cumberland) and significant precipitation amounts in adjacent counties in eastern North Carolina. The Lumber, Neuse, and Little Pee Dee Rivers had record flood crests, exceeding those of the combined Hurricanes Dennis and Floyd in September 1999 that struck a similar area.

Some lessons regarding water wells were drawn from the earlier Hurricane Floyd, which helped at least one community get through the later Hurricane Matthew in somewhat better shape, groundwater-wise.

Well Impacts from Flooding

Water quality and well structure can be affected by flooding. If a well is not sufficiently elevated nor properly capped, grouted, or sealed, contaminated floodwater and sediment can enter the well (National Ground Water Association 2014).

The North Carolina Administrative Code, Standards of Construction: Water Supply Wells, requires water wells be completed at least 12 inches above land surface (North Carolina Department of Environment and Natural Resources Division of Water Quality 2009), with guidance from the Federal Emergency Management Agency for new construction to be 12 inches or more above the 100-year floodplain (U.S. Department of Homeland Security, Federal Emergency Management Agency 2017).

Debris, such as trees and branches or portions of structures that can float, can strike a well and damage it. Open dug wells can be particularly vulnerable to contamination. Contaminants may include coliform and Ecoli from human and animal waste that are indicators of other harmful microorganisms.

Support to Flooded Well Owners

The state offered free well water sample testing to well owners. A total of 1940 sample kits were sent to county health agencies and 294 were returned with well water samples for testing (15% return rate).

The state laboratory received water well samples from 19 counties in eastern North Carolina, and about 22% of the wells tested positive for coliform, E. coli, or both (Price 2017). Thirty-two (32) wells were sampled two to four times to check that the wells were safe for use. Additionally, 24 wells tested positive for coliform or E. coli but did not have samples submitted for retesting, potentially presenting a health risk to the well users.

While the state worked through county health agencies to let well owners know of the free water well testing, the response was less than expected. After all, more than 3 million people in North Carolina rely on private wells for their primary water source (University of North Carolina Gillings School of Global Health 2017).

Some of the reasons given for the response were areas converting to public water systems following the hurricane, concerns about wells being condemned or unusable, and a lack of promotion and education (North Carolina State Laboratory 2017).

The North Carolina Ground Water Association offered a $100 rebate for chlorination or disinfection services provided to owners of flooded wells (North Carolina Ground Water Association 2016). Well owners with flooded wells who had a well service contractor come to their property and disinfect and sample their well could send in their bill to the association and receive a rebate of that portion of their disinfection costs.

Responding to Homeowners

Water well contractors provided assistance to both homeowners with private wells and communities on municipal wells.

Bill Magette of Magette Well and Pump Co. in Ahoskie, North Carolina, and Russell Underwood of Charles R. Underwood Inc. (CRU) in Sanford, North Carolina, recall responding to the groundwater needs of flood victims and communities.

Magette Well and Pump responded to flooded wells at six residences in the Hertford County area with disinfection and bacteriological testing to ensure the wells were safe for homeowner use.

Typical cost of disinfection through chlorination and bacteriological testing of a well is $80-$200 depending on wellhead access, well depth, and well diameter. Because of the potential health, taste, and odor problems—and the possibility for damaging the well and pump from mismanaging disinfection chemicals or opening the well—well owners should always use a qualified well services contractor.

During Hurricane Floyd, Bill Magette recalls responding to 15 flooded wells at residences in the eastern part of the state. At the time, he also helped another homeowner recover from his flooded and contaminated well situated near the area’s wastewater treatment plant. After several chlorinations and tests, the well water was determined not usable. Magette’s company then installed a new deeper well to avoid the significant groundwater contamination suspected from the treatment plant.

Assisting Communities

CRU assisted well owners in Lumberton, which was badly damaged by flooding from Hurricane Matthew. Lumberton (population 21,499 in 2016) in Robeson County has standby wells to blend with Lumber River water to meet drinking water standards. The wells were flooded by the hurricane’s rains and the city’s water plant, which was flooded and inoperable, could not supply water.

Russell Underwood reports CRU disinfected seven Lumberton municipal wells, meeting drinking water standards in just a few days. The wells provided 24-hour water supply for three weeks until the water treatment plant was back in operation. The same wells also supplied nearby areas through water delivery by water tankers.

‘Take-Away’ Pointers from Hurricane Floyd

In Greenville, the water plant, drawing mainly on the Tar River, and its backup wells were flooded by Hurricane Floyd.

Magette Well & Pump had previously rehabilitated and relined several wells for the city of Greenville prior to the Hurricane Floyd flooding. After that hurricane, Magette chlorinated two of the wells that then supplied the city for a month until the water plant was back in operation. The wells also supplied the surrounding areas using water tank truck delivery.

But after Hurricane Floyd in 1999, Magette Well & Pump also added well casing to raise the wellhead elevations 2 feet above the flood level. During Hurricane Matthew in 2016, Greenville had no problems with its wells being flooded. Lesson learned: Planning for weather extremes is important even for groundwater systems.

Several “take-aways” may be garnered from the North Carolina experience with flooded wells potentially improving their sustainability:

  • Advertise flood response and recovery services and support in advance of extreme weather, perhaps even regularly throughout the flood season. June 1 is the typical “official” start of hurricane season on the U.S. East and Gulf coasts.
  • Link communication about supporting services for flooded wells—free well water testing (state), rebates for well disinfection (North Carolina Ground Water Association), and well services offered (contractors)—to make it easy for homeowners on well systems to know the full scope of services available to them.
  • Educate homeowners and municipal water system operators about the utility of elevating their well casing above flood levels and locating new wells in locations of higher elevation to avoid flooding wherever possible.

 References

National Ground Water Association. 2014. Household water well owners should inform themselves about flood threats. www.ngwa.org/Media-Center/press/2014/Pages2014-04-28-flooding.aspx. Accessed July 22, 2017.

North Carolina Department of Environment and Natural Resources Division of Water Quality. 2009. North Carolina Administrative Code Title 15A. 15A NCAC 02C .0107 (d) Casing (5).

North Carolina Ground Water Association. 2016. Flood Victim Rebate Program.

North Carolina State Laboratory. 2017. Hurricane Matthew Sample Collection Kits (tracking matrix). February 28, 2017.

Price, Cindy 2017. Written communication, August 4, 2017.

University of North Carolina Gillings School of Global Health. 2017. Groundwater in North Carolina. http://sph.unc.edu/superfund-pages/ncwellwater/groundwater-in-north-carolina. Accessed July 22, 2017.

U.S. Department of Homeland Security, Federal Emergency Management Agency. 2017. Higher Floodplain Management Standards: A Valuable Element in Community Planning. www.fema.gov/media-library-data/1436818440760-e98afeaaf063ee3417e6a76a62fb0a48/FPM_1_Page_Higher_FPM_Standards.pdf.


Chuck Job is the manager of regulatory affairs for the National Ground Water Association, a position he has held since December 2015. Prior to that, he worked at the U.S. Environmental Protection Agency for more than 29 years, having served since 2000 as its Infrastructure Branch chief. During part of his agency tenure, Job worked in EPA Region V in groundwater protection and water quality standards planning. He can be reached at cjob@ngwa.org.

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