Seabrook Island Utility Commission Overview
November 30, 2022
Seabrook Island Utility Commission Overview
In the last few weeks, the Seabrook Island Utility Commission (SIUC) has received a handful of questions regarding our water and sewer service obligations and questions about available and future sewer treatment capacity. Below is a bit of history and an overview of the current status.
Service Area Obligations
The Town of Seabrook Island purchased the water and sewer business from a private entity in 1995 through an Ordinance that established the Seabrook Island Utility Commission. At that time the Town agreed to accept the existing obligations to provide sewer treatment to limited areas outside of Seabrook. These included Cassique, Kiawah River Estates, Freshfields and the existing Bohicket Marina. Included in this obligation is future development at or near Freshfields, and property along Seabrook Island Road including SeaFields and the proposed MUSC facility. In regard to water supply, SIUC supplies water to Seabrook Island and land on the marina side of Seabrook Island Road only (the proposed MUSC facility and the marina itself).
It remains our intent to service the existing sewer obligations but not to proactively take on extra obligations. If the Town chooses to annex a property, SIUC would then serve that new property as it would then belong to the Town. If the Town chooses not to annex a nearby property, SIUC would not (and could not without Town’s approval) choose to provide service to such a property.
Water Capacity - SIUC purchases all the water we deliver to our customers from St. John’s Water Company, which in turn purchases it from Charleston Water. We do not and cannot treat the water in any way as we are not licensed to do so. We simply pass the already treated water from St. Johns Water to our customers. We have plenty of water capacity to serve our mainly Seabrook customers.
Sewer Capacity - For all new customers, it is our policy (similar to many utilities) that new customers build their own sewer lines at their cost all the way to our main line and then deed that infrastructure to SIUC. Regarding the impact a new customer has on the larger sewer treatment infrastructure and the potential cost to expand our treatment capacity, SIUC believes that existing customers should not have to foot this bill. As such, we charge all incoming customers an impact fee when they connect. In the past two years we have increased this impact fee roughly 300% based on engineering studies that estimate what our future sewer treatment expansion would look like and those said costs. Not surprisingly these costs have increased in the last couple of years and as such so has our impact fee.
Our existing sewer treatment capacity is 1.1 million gallons/day. On most days we treat between 40% and 60% of our maximum capacity (so 400,000 - 600,000 gallons per day). That said, a sewer treatment facility would not want to run at or near full capacity given periodic planned and unplanned maintenance outages.
The following is a high level view of the impact of new or potential projects near Seabrook that we are obligated to serve if they are built. These are estimates but they provide a general idea. Capacity estimates are based on average flow not peak flow. None of these projects are built and none of these projects have paid any impact fee.
Seafields – 36,000 gallons/day (gpd) peak flow - Actual daily flow will probably average 24,000 gpd. This is about 2.2% of our capacity.
MUSC - 6,000 gpd peak flow - Actual daily flow will probably average 4,000 gpd. This is 0.4% of our capacity.
The new Grocery Store and Retail (Kiawah Partners) - 12,000 gpd peak flow - Actual daily flow will probably average 8,000 gpd. This is 0.8% of our capacity.
Marina expansion - 10,675 gpd peak flow - Actual daily flow will probably average 7,136 gpd. This is approximately 0.7% of our capacity. Note that we are only going to serve this facility if the Town decides to annex the property.
Potential Andell 400 acres adjacent to Freshfields (Kiawah Partners) at four units/acre = 480,000 gpd peak flow – Actual daily flow will probably average 320,000 gpd. This is much more significant at 30% of our capacity.
To conclude, SIUC is obligated to provide sewer service to most of the anticipated growth areas immediately outside of Seabrook. When these developments are built out, the development is directly responsible for installing and paying for all the infrastructure for their development to the point of hook up with the SIUC system. Further, the developments pay an impact fee to SIUC that goes towards their share of future capacity infrastructure. Thus, these developments should not financially impact existing SIUC customers.
SIUC is actively planning for the future needs of our customers and we are committed to continuing to provide excellent service both in water and sewage.
Annie Smith-Jones, Chair
Seabrook Island Utility Commission