NC0025381_correspondence (WTP discharge)_20191120

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To: Shannon Baldwin and Kurt Wright
From: Buddy Melton
Date: November 20, 2019
Re: Lake Lure Assisted Living drinking water treatment discharge
In follow up to our conversations concerning the potential of The Town of Lake Lure wastewater treatment plant
accepting the backwash regeneration waste from the proposed ion exchange treatment needed for the Lake Lure
Assisted Living facility. I wanted to provide you with some facts and design figures for your review. The well drilled to
serve the Assisted Living had radiological levels above the drinking water standards and must be treated in order to
meet drinking water standards. The following is the information pertaining to the discharge flow levels and impacts
from the treatment waste.
Based on the engineering design for the well treatment for the Assisted Living facility, the frequency of
backwash/regeneration is anticipated to be every 22 days and will be 500 gallons in volume. The concentration of
radium in the brine waste will be ^' 1691 pCi/L. This would dilute to 0.28 pCi/L Ra in the wastewater at the low
wastewater facility flow rate of 275,000 gpd and to 0.13 pCi/L at the average wastewater facility flow rate of 600,000
gpd. The facility flow rate numbers are based on the information provided by Don Byers of Byers Environmental with
the lowest flow of 275,000 gpd seen with the lake drained and 600,000 gpd being the current average daily flows.
For permit modification most States are reasonable in considering that the same mass (or energy) of isotopes is going
through the system after treatment as what is (and has been) going through without treatment. The concentrations in
the wastewater resulting from treatment is well below drinking water standards with the drinking water standard of
combined radium being 5 pCi/L. With the projected numbers entering the wastewater system once every three weeks,
the impact is low. Operation for a radium (cation) removal system is the same as any water softener but with a better
service period between regenerations.
Please feel free to contact me if you want to discuss or if you have additional questions or needs. Once you all have had
a chance to review the preliminary data we can discuss the modification of the existing permit process.
We really appreciate your willingness to consider this modification. It will be a great assistance in moving the project
forward and the best long-term disposal option.
Thanks
Mailing Address: P.O. Box 5432, Asheville, NC 28813
168 Patton Avenue Asheville, NC 28801 52 Walnut Street- Suite 9, Waynesville, NC 28786
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