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Home My WebLink AboutWQ0017530_Non-compliance Reporting_20210909LandWorks Engineering, PLLC PO Box 1922, Asheville, NC 28802 828-230-7958 P.2 of 2 LandWorks Engineering Land Planning & Civil Engineering Ms. Mikal Wilmer Environmental Specialist NCDEQ- Asheville Regional Office 2090 US Hwy 70 Swannanoa, NC 28778 RE: Wet Weather Pond Failure/Discharge Highlands Cove WWTP Reclaimed Water Generation and Dedicated Utilization System Jackson County Permit No. WQ0017530 As a result of the rainfall of Hurricane Ida the wet weather pond dam and liner were compromised and a resulting discharge occurred over the period of 8/31 – 9/2 The Wet weather storage Pond was installed in the year 2000 Total Pond Storage Volume = 3,198,560 Gallons Timeline as reported by Jerry West of Highlands Cove and Mark Teague, Environmental Inc. the Highlands Cove, ORC: • Friday 8/27/21 – ORC Mark Teague w/ Environmental Inc. observed and recorded the current water elevation within the lined Wet weather Pond of 13.8 feet above the Pond Bottom 3695.0 or Elevation 3708.8 • Tuesday 8/31/2021, Wednesday 9/1/2021 As a result of Hurricane Ida and 8+/- inches of rainfall the Grassy Camp Creek 2-79-23-4-1 WS- III waters in front of the dam filled to levels unseen and shifted large boulders protecting the dam toe resulting in the pond liner tearing and allowing the pond to seep, oversaturate the dam and discharge via a dam breach along the underdrain discharge. • Thursday 9/2/2021 Jerry West was alerted to the tear in the liner and resulting Dam and golf course wash by his Golf Course Maintenance Crew. Jerry contacted Mark Teague with Environmental Inc and the inspected the Pond together. The Pond level had discharged to the bottom of the tear 11.2 feet above the pond bottom or elevation 3705.9 The pond had dropped a total of 2.9 feet plus the rainfall amount. • Thursday 9/2/2021 I was alerted to the Pond Condition on in a phone message from the Mark Teague the ORC. I was out of town away from the office. • Friday 9/3/2021 - Discussed making emergency repairs to the Dam and Pond to prevent the further discharge of treated wastewater. Mark Teague the ORC moved water around to the 5 Day Emergency pond and lowered the level in the Wet Weather Pond to 8.9 feet above the Pond Bottom providing 2 feet of freeboard upto the tear elevation as an emergency measure. Discussed implementing increased application to remove treated effluent from the pond in compliance with the permit. Contacted JGHarris Construction & others, requesting inspection and repair/replacement of the Pond liner as it is 20+ years old. • 9/08/2021, After the Labor Day Holiday weekend, The ORC reported the treated wastewater pond discharge to NCDEQ-Water Resources, Mikal Wilmer, Landon Davidson. LandWorks Engineering, PLLC PO Box 1922, Asheville, NC 28802 828-230-7958 P.2 of 2 Highlands Cove Wet Weather Pond Vol: Elev-Area Elevation Planimeter Area A1+A2+sqr(A1*A2) Volume Volume (ft) (sq.in) (sq.ft) (sq.ft) (cu.ft) (cu.ft) ---------------------------------------------------------------------- 3695.00 ----- 6868 0 0 0 3696.00 ----- 19254 37621 12540 12540 3697.00 ----- 19992 58866 19622 32162 3698.00 ----- 20737 61090 20363 52526 3699.00 ----- 21490 63337 21112 73638 3700.00 ----- 22251 65608 21869 95507 3701.00 ----- 23020 67903 22634 118142 3702.00 ----- 23796 70221 23407 141549 3703.00 ----- 24581 72562 24187 165736 3704.00 ----- 25374 74929 24976 190713 3705.00 ----- 26175 77320 25773 216486 3705.90 ----- 26888 79592 23875 240361 3706.00 ----- 26983 80806 2696 243057 3707.00 ----- 27800 82171 27390 270448 3708.00 ----- 28624 84633 28211 298659 3708.80 ----- 29258 86821 23154 321813 3709.00 ----- 29457 88072 5870 327683 3710.00 ----- 30297 89628 29876 357559 POND VOLUME EQUATIONS Incremental volume computed by the Conic Method for Reservoir Volumes. Volume = (1/3) * (EL2-EL1) * (Area1 + Area2 + sq.rt.(Area1*Area2)) Where: EL1, EL2 = Lower and upper elevations of the increment Area1,Area2 = Areas computed for EL1, EL2, respectively Volume = Incremental volume between EL1 and EL2 Treated Effluent Wastewater Discharge Estimate • Volume in the Pond Friday 8/27/2021 at Elevation 3708.8 = 321,813 CF =2,407,161 Gallons. • Volume in the Pond after Discharge, Thursday 9/2/2021 at Elevation 3705.9 = 240,341 CF = 1,797,751 Gallons • Calculated Discharge Volume = 81,452 CF = 609,260 Gallons Please let me know if you have any questions or need additional information. Respectfully Submitted, Marty Kocot, PE Landworks Engineering, PLLC