Mt. Pleasant SC 1
Mt. Pleasant SC 3 edit
Mt. Pleasant SC 2 edit


The Challenge

Mount Pleasant Waterworks in South Carolina, a private utility, was planning a plant expansion to better serve its customers when an emergency short-term need arose. With the spring high-flow season approaching, the plant faced a shortfall in treatment capacity. Management considered two options: renting a unit or building a temporary, disposable unit. Both options would be costly, an estimated $30,000-$40,000 per month for a rental unit or $160,000 or more for a temporary, disposable one. Moreover, neither option would necessarily deliver the dependability Mt. Pleasant needed. The assumption that these were the only two options may have been right for other companies but not for Harn R/O. Based on its working knowledge of water treatment plants and the unique needs of their owners and operators, Harn came up with an innovative solution that was less costly, more dependable and delivered long-term value.

The Solution

Harn R/O Systems built a new unit in less than three months and installed it outside the plant on railroad ties under a protective tent. Connected directly to the well, it was intended to run for six months but ran for two years as Harn worked with Mt. Pleasant on the overall plant expansion. Once the new plant was built, Harn moved the "temporary" skid in as it built and installed another new unit to meet Mt. Pleasant’s overall needs. Most importantly, this innovative solution enabled Mt. Pleasant Water Works to serve its customers’ needs with no shortfalls or problems.

The Result

“Harn’s solution was not only innovative but it saved our utility a significant amount of money,” said Greg Hill of Mt. Pleasant Water Works. “The one-time capital expense for a unit that will run for 20 years or more cost less than it would to rent a temporary unit for six months. Plus, the unit could then be incorporated into our permanent installation. Harn’s knowledge, experience and commitment to quality delivered far more than just equipment for our plant. They were a partner in ensuring quality and service to our customers.”



Mount Pleasant Waterworks

Thomas Hutton

Potable drinking water

2001/ 2004 

1.7 MGD

10:5, 7-element vessels, 2 trains

Hydraulics ESPA2

Operating Data:
Feedwater TDS: 1,600 mg/l Permeate TDS: 200 mg/l R/O Feed Pressure: 120psi Recovery: 80%

System Features:
  • Temporary skid modified to incorporate interstage boost when relocated in plant
  • High Temperature feedwater results in low operating pressures
  • Low raw water calcium levels enables high recovery operation without use of scale inhibitor.


  • Hilton Head, SC

    Hilton Head, SC

    The South Island Public Service District (SIPSD) in Hilton Head, SC, chose an innovative procurement process to carefully assemble a
    Read More
  • Mt. Pleasant, SC

    Mt. Pleasant, SC

    Mount Pleasant Waterworks in South Carolina, a private utility, was planning a plant expansion to better serve its customers when
    Read More
  • Lancaster, OH

    Lancaster, OH

    The City of Lancaster, Ohio realized it had to replace its aging ion exchange water treatment facility with a new
    Read More


  • Palm Coast, FL

    Palm Coast, FL

    The City of Palm Coast, FL, had built a water treatment facility for the future. Unfortunately, faster-than-expected growth, not unusual
    Read More
  • Sarasota, FL

    Sarasota, FL

    The City of Sarasota, FL needed to retrofit its sole water plant from the existing hollow fiber membrane reverse osmosis
    Read More