Chesapeake Ranch Water Company (CRWC) owns and operates the potable drinking water system and fire protection for approximately 4,000 homes and businesses over five square miles in scenic Lusby, Maryland. We are a fully functioning public community water supply system for nearly 10,000 residents of Chesapeake Ranch Estates and an adjacent small retail section.
CRWC’s water system contains two elevated storage tanks with a combined system storage of 750,000 gallons, more than 70 miles of distribution lines, supplying water to many residential cul de sacs, and four deep groundwater wells. When CRWC began experiencing elevated arsenic levels at one of the wells in the late 1990s, we began an extensive evaluation to determine the best way to meet regulations and continue to provide high quality water to our Lusby community.
One option we considered was to abandon the well. Because losing 25% of our capacity would require us to dig a new well into a different aquifer, it was estimated that this option would have cost between $1,000,000 and $1,500,000. There would be no assurances that water from the new well wouldn’t contain elevated levels of arsenic or need to be treated in other ways. With the cost and risks of ongoing arsenic contamination, it was decided that installing an arsenic removal system would be a better option, but one that would come with its own set of challenges.
With only a small 60’ x 120’ lot available for an arsenic removal system, the design and size was a major consideration. Even if the system itself would fit within that space, many systems require an additional large area for wastewater disposal. We simply didn’t have the space. In addition, wastewater disposal can come with a hefty cost for effluent permitting. We would need to be creative in our arsenic removal system design and find the right system to fit our space, cost, and permitting constraints.
In 2014, CRWC installed an iron oxide arsenic removal system from De Nora. This solution allowed us to retain all four of our wells, and fit into the available space without additional permitting or wastewater disposal requirements. With over two decades of experience, we felt De Nora was the right partner to help us meet regulations and keep our water healthy and our community safe.
The system has been running smoothly since it started operation in 2014. The entire system is SCADA automated, which allows us to minimize labor costs. With only four of us on the team, time spent caring for our equipment matters.
De Nora was able to design a treatment bypass and blending scheme as well as a pH adjustment that contributed to an estimated 76% increase in media life, significantly reducing operating costs. To lower capital costs, the system was designed to be operated largely manually. This works for a system like ours because of the intentionally simple design of the SORB 33 system.
Today, Chesapeake Ranch Water Company consistently reports arsenic levels of 5 ppb or less, enjoying the benefits of ease of operation, cost effectiveness, low maintenance, and the reinforced cost savings over other, more expensive options to reduce the arsenic levels in our water supply. It’s been very easy to own and operate over the years. Really, we just watch the system operate itself.