WQ0018992_Staff Report_20200724

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
State of North Carolina
®r- Division of Water Resources
Water Quality Regional Operations Section
Environmental Staff Report
Quality
To: ❑ NPDES Unit ® Non -Discharge Unit Application No.: WQ0018992
Attn: Vivien Zhong Facility name: Southwinds WWTF
From: Helen Perez
Wilmington Regional Office
Note: This form has been adapted from the non -discharge fg acili , staff report to document the review of both non -
discharge and NPDES permit applications and/or renewals. Please complete all sections as they are applicable.
I. GENERAL AND SITE VISIT INFORMATION
1. Was a site visit conducted? ® Yes or ❑ No
a. Date of site visit: 07/23/2020
b. Site visit conducted by: Helen Perez
c. Inspection report attached? ❑ Yes or ® No
d. Person contacted: Karrie Omara and their contact information: 252 - 725 ext. 2319
e. Driving directions: 2008 E. Fort Macon Road
2. Discharge Point(s): N/A
Latitude: Longitude:
Latitude: Longitude:
3. Receiving stream or affected surface waters: N/A
Classification:
River Basin and Subbasin No.
Describe receiving stream features and pertinent downstream uses:
II. PROPOSED FACILITIES: NEW APPLICATIONS - N/A
1. Facility Classification: (Please attach completed rating sheet to be attached to issued permit)
Proposed flow:
Current permitted flow:
2. Are the new treatment facilities adequate for the type of waste and disposal system? ❑ Yes or ❑ No
If no, explain:
3. Are site conditions (soils, depth to water table, etc) consistent with the submitted reports? ❑ Yes ❑ No ❑ N/A
If no, please explain:
4. Do the plans and site map represent the actual site (property lines, wells, etc.)? ❑ Yes ❑ No ❑ N/A
If no, please explain:
5. Is the proposed residuals management plan adequate? ❑ Yes ❑ No ❑ N/A
If no, please explain:
FORM: WQROSSR 04-14 Page 1 of 6

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
6. Are the proposed application rates (e.g., hydraulic, nutrient) acceptable`? ❑ Yes ❑ No ❑ N/A
If no, please explain:
7. Are there any setback conflicts for proposed treatment, storage and disposal sites? ❑ Yes or ❑ No
If yes, attach a map showing conflict areas.
8. Is the proposed or existing groundwater monitoring program adequate? ❑ Yes ❑ No ❑ N/A
If no, explain and recommend any changes to the groundwater monitoring program:
9. For residuals, will seasonal or other restrictions be required? ❑ Yes ❑ No ❑ N/A
If yes, attach list of sites with restrictions (Certification B)
Describe the residuals handling and utilization scheme:
10. Possible toxic impacts to surface waters:
11. Pretreatment Program (POTWs only):
III. EXISTING FACILITIES: MODIFICATION AND RENEWAL APPLICATIONS
1. Are there appropriately certified Operators in Charge (ORCs) for the facility? ® Yes ❑ No ❑ N/A
ORC: Lee Buck Certificate #: 993396 Backup ORC: Karrie Omara Certificate
#:14393
2. Are the design, maintenance and operation of the treatment facilities adequate for the type of waste and disposal
system? ® Yes or ❑ No
If no, please explain:
Description of existing facilities:
continued operation of a 43, 200 gallon per day (GPD) wastewater treatment and high -rate infiltration
facility consisting of:
one 90-gallon per minute static screen; one 15, 000-gallon aerated flow equalization tank (aeration provided by aeration
tank blower) and two 45- gallon per minute wastewater transfer pumps; one flow splitter box with 30 " V"- notch weirs;
two aeration trains, each with seven 5, 000- gallon compartments to provide a minimum of 34 hours of hydraulic
detention; two 10- horsepower blowers to fuel a coarse bubble aeration system; two clarifiers, each with 5, 000 gallons of
useable volume to provide a minimum of 5. 5 hours of hydraulic detention and one airlift surface skimming unit; two
tertiary filtration units, each with 19. 6 square feet of filtration area to provide a loading rate of 0. 77 gallons per
minute per square foot, one 5, 000- gallon clearwell ( i. e., combined volume of filter dosing and backwash
tank), and one 5, 000- gallon mudwell; a tablet chlorination system with contact time to be provided in the
dosing tank associated with the non -discharge disposal facilities; one flow measurement device and
stilling well to record the volume of wastewater effluent being generated; one 5, 000- gallon aerated sludge
holding tank ( i. e., aeration provided by aeration tank blowers) and one airlift decanting unit, and all
associated piping, valves, electrical and instrumentation systems, and other appurtenances.
one 3, 000- gallon dosing tank with two 48- gallon per minute pumps; a headworks box containing two
vortex filters, two manual filter flush valves, and two manual flush valves; approximately 1, 121 linear feet of three- inch
supply line to send wastewater effluent to both Surface Drip Disposal Field No. I and Surface Drip Disposal Field No. 2;
one 11, 262- square foot high -rate drip irrigation field, divided into two zones ( i. e., Surface Drip Disposal Field No. I
with 5, 630 square feet of wetted area and Surface Drip Disposal Field No. 2 with 5, 632 square feet of wetted
area) with dripper lines, having 1. 02- gallon per hour emitters every one foot; approximately 1, 224 linear feet of three-
inch return line to return wastewater effluent not irrigated on Surface Drip Disposal Field No. I and Surface Drip Disposal
Field No. 2 to the equalization tank; and all associated piping, valves, electrical and instrumentation/ control systems, and
other appurtenances.
FORM: WQROSSR 04-14 Page 2 of 6

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
Proposed flow:
Current permitted flow: 43,200 gpd
Explain anything observed during the site visit that needs to be addressed by the permit, or that may be important
for the permit writer to know (i.e., equipment condition, function, maintenance, a change in facility ownership,
etc.) Static screen at headworks is not currently being used and no plans to use it in the future due to problems
with disposal of screenings it produces. Manual screening is performed instead. The annual soil analyses (Section
IV.11) are not conducted because the facility has drip fields with a landscaping cloth covered by recycled rubber
tire mulch. Almost half of the condo buildings are not occupied due to damage from hurricanes Florence and
Dorian. The buildings are currently being repaired. There is only one supply line to the drip fields current permit
lists two separate lines), therefore both drip fields are dosed at the same time. Staff indicated that there has alwas
been only one line. There is no chlorine contact chamber and never had one. The dosing tank acts as a contact
chamber but it's not an optimal design.
3. Are the site conditions (e.g., soils, topography, depth to water table, etc) maintained appropriately and adequately
assimilating the waste? ® Yes or ❑ No
If no, please explain:
4. Has the site changed in any way that may affect the permit (e.g., drainage added, new wells inside the compliance
boundary, new development, etc.)? ❑ Yes or ® No
If yes, please explain:
5. Is the residuals management plan adequate? ® Yes or ❑ No
If no, please explain:
6. Are the existing application rates (e.g., hydraulic, nutrient) still acceptable? ® Yes or ❑ No
If no, please explain:
7. Is the existing groundwater monitoring program adequate? ® Yes ❑ No ❑ N/A
If no, explain and recommend any changes to the groundwater monitoring program:
8. Are there any setback conflicts for existing treatment, storage and disposal sites? ❑ Yes or ® No
If yes, attach a map showing conflict areas.
9. Is the description of the facilities as written in the existing permit correct? ❑ Yes or ® No
If no, please explain: There is no manual bar screen; no 2 hp blower for EQ, aeration provided by aeration tank
blower; only one supply line to the drip fields. See description in section III.2 above.
10. Were monitoring wells properly constructed and located? ® Yes ❑ No ❑ N/A
If no, please explain:
11. Are the monitoring well coordinates correct in BIMS? ® Yes ❑ No ❑ N/A
If no, please complete the following (expand table if necessary):
Monitoring Well
Latitude
Longitude
O / //
O / II
OFF1
o , „
O / //
O I If
O / //
O I If
O / 1/
O I If
12. Has a review of all self -monitoring data been conducted (e.g., DMR, NDMR, NDAR, GW)? ® Yes or ❑ No
Please summarize any findings resulting from this review: For the permit cycle: 3 daily effluent fecal
exceedances, 2/19, 8/17,and 5/16. GW59s show slight elevation in TDS (barrier island environment) and a nitrate
exceedance in 12/16 in MW3.
Provide input to help the permit writer evaluate any requests for reduced monitoring, if applicable.
13. Are there any permit changes needed in order to address ongoing BIMS violations? ❑ Yes or ® No
If yes, please explain:
FORM: WQROSSR 04-14 Page 3 of 6

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
14. Check all that apply:
® No compliance issues ❑ Current enforcement action(s) ❑ Currently under JOC
❑ Notice(s) of violation ❑ Currently under SOC ❑ Currently under moratorium
Please explain and attach any documents that may help clarify answer/comments (i.e., NOV, NOD, etc.)
If the facility has had compliance problems during the permit cycle, please explain the status. Has the RO been
working with the Permittee? Is a solution underway or in place?
Have all compliance dates/conditions in the existing permit been satisfied? ❑ Yes ❑ No ® N/A
If no, please explain:
15. Are there any issues related to compliance/enforcement that should be resolved before issuing this permit?
❑ Yes ®No❑N/A
If yes, please explain:
16. Possible toxic impacts to surface waters: N/A
17. Pretreatment Program (POTWs only): N/A
FORM: WQROSSR 04-14 Page 4 of 6

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
REGIONAL OFFICE RECOMMENDATIONS
1. Do you foresee any problems with issuance/renewal of this permit`? ❑ Yes or ® No
If yes, please explain:
2. List any items that you would like the NPDES Unit or Non -Discharge Unit Central Office to obtain through an
additional information request:
Item Reason
3. List specific permit conditions recommended to be removed from the permit when issued:
Condition
Reason
Section III.15
The facility has high -rate drip fields that are covered with a landscape cloth
covered by recycled rubber tire mulch. They are not infiltration basins that can
be dredged.
Section W. I I
Annual soil analyses are not needed because there is no vegetation allowed to
row for proper infiltration.
4. List specific special conditions or compliance schedules recommended to be included in the permit when issued:
Condition Reason
5. Recommendation: ❑ Hold, pending receipt and review of additional information by regional office
❑ Hold, pending review of draft permit by regional office
❑ Issue upon receipt of needed additional information
® Issue
❑ Deny (Please state reasons: )
/—DocuSigned by:
6. Signature of report preparer:
Signature of regional supervisor:
Date: 7/24/2020
DocuSigned by: M J��,�(�� eV Sa" -_"-' / 6"
E3ABA14AC7DC434...
FORM: WQROSSR 04-14 Page 5 of 6

DocuSign Envelope ID: FD1E49D1-D4D0-4668-8392-600CB1AF4704
IV. ADDITIONAL REGIONAL STAFF REVIEW ITEMS
This staff report was prepared for the renewal of Permit W00018992, Southwinds WWTF. The permit expires on
September 30, 2020. There have been no changes to the facility during the permit cycle and no compliance issues.
Flow this summer is averaging gpproximately 10,000-15,000 gpd. Almost half of the condo buildings suffered
damages from Hurricanes Florence and Dorian and are still being repaired.
There are changes to the description of the current permit and permit conditions that were recommended to be
removed that are noted in the report.
FORM: WQROSSR 04-14 Page 6 of 6