National Groundwater Awareness Week
Keith Webb Answers Our Questions on this Vital Resource
National Groundwater Awareness Week was created by the National Ground Water Association (NGWA) to call attention to one of our most precious and vital resources – groundwater.
In honor of Groundwater Awareness Week, we asked Keith Webb, PE – Principal and Vice President of McGill – some questions about groundwater. Keith has over 40 years of experience as an engineer with many of his projects involving water supply, treatment, and storage. He understands the importance of this most critical resource and provides more insight into its impact on communities.
What is groundwater and why is it important?
Webb: Groundwater is water obtained from below the Earth’s surface and is typically stored within the underlying soil / rock geological material and features. Groundwater is an important natural resource that is used for potable water supply for many residents of North Carolina, Tennessee, and Virginia, not to mention for most of America. Groundwater is the only option of water supply for most rural homes. In North Carolina, it is estimated that groundwater supplies approximately 169 million gallons per day (MGD) of drinking water.
Groundwater is critically important, as it supplies safe drinking water to sustain life and maintain acceptable levels of life and sanitation for Americans.
How does the quality of groundwater compare to surface water?
Webb: Typically, groundwater quality is excellent and a person can use the water without treatment. Treatment has typically occurred due to the natural filtration of the overlying soil and rock. In some cases, treatment may be required to reduce levels of iron, manganese, and other chemicals. Groundwater is usually much cleaner than surface water, as a result of the natural filtration of the overlying soil and rock.
How do groundwater and surface water differ?
Webb: Surface water has higher levels of sediment and other microcontaminants. It requires filtration and disinfection prior to use for potable water and human consumption. However, surface water in North Carolina is normally more abundant and in higher quantities.
Is the groundwater different in certain regions (in quantity, availability, quality, ease of utilizing, etc.)?
Webb: Yes, depending upon the region of North Carolina, the location and quantity of groundwater varies significantly. In Eastern North Carolina (coastal plains), groundwater is found in well-defined underground aquifers and the quantity and quality is somewhat well defined. However, this region has capacity use restrictions, as a result of the number of users and the concerns for saltwater intrusion into the groundwater supply. In the piedmont and mountain region, groundwater is obtained from cracks and fractures in the underlying rock formations, and the quantity of groundwater is more limited.
How does it affect communities and their economy?
Webb: Development of new well supplies is expensive, but typically less than a surface water supply. Cost per 1,000 gallons of water is typically less than an equivalent 1,000 gallons from a surface water supply.
What type of work does McGill do that involves groundwater protection?
Webb: McGill helps clients identify potential locations for new groundwater supply wells, obtain the necessary approvals from various regulatory agencies for the well, assist clients with construction of the well, design and properly size the groundwater well pump and connection into the utilities water distribution system, and design treatment systems required for these new water supplies. McGill provides complete project management for our clients, including assistance with project bidding, contracting, and overseeing construction and funding.
Can you give an example of a recent project and how you overcame any unique challenges?
Webb: One example is the water supply for the Biltmore Estate in Asheville, North Carolina. Water demands for the Biltmore Estate have grown from 20,000 gallons per day (GPD) in 1990 to approximately 125,000 GPD today. This increase in demand is a result of tourist amenity development at the Estate, including two hotels and numerous restaurants, not to mention increased visitation. Historically, the Estate purchased 100% of its potable water supply from the City of Asheville. Managers became concerned with the vulnerability of the single City connection and the negative impacts a service line break or drought conditions experienced by the Asheville system’s effects on the Estate – impacts both from services for guests and other functions of the Estate, plus economic impacts.
To reduce vulnerability and improve resiliency of the water supply system, McGill helped the Estate locate, permit, and develop two groundwater supply wells and the infrastructure to connect these into the Estate’s water distribution system. Improvements included two new 100,000 GPD water, disinfection, and treatment facilities, as well as a new 200,000-gallon, prestressed concrete water storage tank to provide additional storage of potable water.
What else do you want to share with us about groundwater awareness?
Webb: Water is life and an important component for the economy of our clients and the safety and health of their citizens. Groundwater can and does play an important role for utilities and municipalities to meet these needs. The protection of groundwater quality is critically important, which requires the need for the proper treatment and disposal of wastewater to protect the groundwater supply. We all have an impact on groundwater and should be aware that the way we use the water and efforts to reduce the amount we each use and reduce contamination – which can find its way into the groundwater supply – are important.
Speaking Up for Groundwater
Groundwater is important to all communities. The more we are educated and aware of it, the more we can make a difference. Thanks to Keith Webb for shedding light on groundwater. If you have questions, please contact us by filling out the form on our contact us form. If you would like to learn about a water treatment project that our team recently completed, check out this case study that highlights our work with the City of Lenoir.