WQ0002284_More Information (Received)_20020326

3
7
March 15, 2002
41
Mr. Nathaniel D. Thornburg,.;~
Environmental Engineer
Non -Discharge Permitting Unit
NCDENR-Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Mpplication Ncr:Y QWQ2_ 4
Aud iorialIpf6rg i6n:Request_
Kinnakeet Wastewater Treatment
Plant Modifications and Reuse
Irrigation System
Dare County
Dear Mr. Thornburg:
Ate: ef 1
Gw�l elt'
Via Overnight Delivery
RECEIVED
WATER QUALITY SECTION!
MAR 21 2002
NQ,1,,MS,Q1+AR.Q5 PER,MJTTINJG
We have reviewed the Additional Information Request for the referenced project, and are
submitting the requested information herewith to enable you to complete your review for
issuance of a permit for this project. The responses outlined below correspond to the
numbering in the additional information request letter:
General:
1. Sets of updated specifications are included, signed, sealed and dated as
required. The specifications include modifications as discussed in future
paragraphs in this letter.
2. A reuse water education package is included in conformance with 15A NCAC
2H .0219 (k) (1) (C) (i) (I>).
3. The subdivision receives potable water from Dare County's Hatteras Island
water distribution system. The wells furnishing this system are located off
site at Buxton, North Carolina.
4. Language is proposed stating that reuse water will be used to irrigate the front
yards of the lots within the subdivision. Homeowners do not have the option
of having reuse water sprayed in their yards, as the utility company has
specifically reserved an easement for that purpose across all of the lots
proposed for irrigation (see attached subdivision plat, typical). In addition,
each homeowner will be furnished a copy of the education literature discussed
in item 2 above.
5. We acknowledge that DWQ will contact us in the future regarding I5A NCAC
2H .0227.
4417 N. Croatan Hwy. ■ P.O. Box 1068 ■ Kitty Hawk NC 27949
252-261-3266 ■ Fax: [phone] ■ E-mail: [e-mail]

Page 2
Mr. Nathaniel D.Thornburg
March 15, 2002
Plans:
Restrictive fencing is included on the plans as requested.
2. The lake to the south of the proposed infiltration pond is an existing lake,
which serves as an aesthetic feature for the subdivision as_ well as a
groundwater control device (ie, a "line sink'. The pond meets the separation
requirements of 15A NCAC 2H.
3. Details"of cleanouts and air release valves to be used -in the proposed reuse
irrigation system are provided on the updated plans.
4. Plans include details of the irrigation sprinkler heads, 'appurtenances, as well
as a tabulation of all of the components to be installed under this project.
Please refer to sheet RRC1.
Specifications:
1. Specification section 11400 has been modified to remove the comminutor.
2. Section 11400 has been modified for the central clarifier.
3. Section 11900 has been modified to include both audio and visual alarms for
the pump stations.
Wastewater Treatment Facility:
1. A hydraulic grade line has been shown for the entire wastewater treatment
system Additional plan clarifications have been >nvqI-e it eerier to
2. Piping has been modified so that the two clarifiers operate in parallel, not in
series. The specification narrative has been amended accordingly.
3. Additional details are provided regarding the piping between the various
components of this system, in particular clarifying aeration basin 3 and the 2°d
clarifier, so that the 2°d clarifier is utilized for both initial, low flow
conditions, and for future, dual path conditions at design flow. A schematic
flow diagram also included.
4. A 5- ay side eam detention pond�(Uned�nd) is be'iT.1+0�„�+,.,A A,c, nuriumally envisioned when the
hydrogeological report was completed. A letter from Edwin Andrews, project
h dro eolo ists is included which acknowledges that t e y rogeo ogica
report applies to the r_ey vement over jje iral
lan-
The five day pond includes a provision for water to be returned to the
head of the treatment works and retreated.
5. Specifications have been provided for the synthetic liner, having a hydraulic
conductivity of less than 1 x 10-6 cm/s.

Page 3
Mr. Nathaniel D. Thomburg
March 15, 2002
6. Calculations are included verifying that sludge holding has at least 30 days of
storage.
7. The Division of Water Quality has determined that the traveling bridge filter
as proposed meets the intent of the dualization criteria
8. Manufacturers information and specifications are included for the backwash
system pumps, as well as groundwater control and 5-day pond return pumps.
9. While not responding to a specific comment, please note that the package
treatment plant includes an anoxic zone for denitrification in order two all, evi�at_e
any concern with groundwater
Reuse Irrigation Sim:
1. The sprinkler system array has been refined so that the spray pattern avoids_
direct application to roads. The am
which does not co ec,�tc2„ _ _ ce wal of the state (e.g., those capable of
ho ing in the 25 year storm) is permissible under e regu ions. a ave
irrigated self contained ponds in the past, which has been acceptable to DWQ.
2. The irrigation drawings have additional information which now clearly shows
the various water classifications within the Kinnakeet Shores Subdivision.
The plans indicate those waters with an SA classification which are subject to
the 100' buffer, isolated wetlands subject to a 25' buffer and isolated ponds
that are not subject to buffering. The actual irrigation setback lines are shown,
with all irrigation occurring outside those setbacks.
3. The reuse irrigation system is zoned in such a manner that each soil series will
receive the appropriate dosage. Details have been provided as to how the
various zones will be dosed and at what frequency in order to avoid
overdosing, based on the soil scientist's report.
4. The actual application rate will not exceed 3.1" per week under the dosing
plan described in Paragraph 3 above. Specific details of this dosing plan are
included.
5. The dredge spoil that was formerly located east of the rotary distributors was
removed by NCDOT and utilized for dune reconstruction on Hatteras Island.
6. The addition of denitrification in the treatment facility has eliminated the
nitrate concern, as nitrates will be removed to a level which is below the
groundwater standard of 10 mg/l. Based on denitrification, the hydrogeologist
has concurred with the current application rate, as indicated in the attached
letter from Ed Andrews.
7. The reuse piping, sprinkler heads and related appurtenances to be installed in
the reuse project have been tabulated on sheet RRC 1.
8. All pump calculations for the irrigation pond pump system are included. The
dosing system calls for the simultaneous dosing of up to 6 zones, and the
pipes have been sized accordingly.

. . •
Page 4
Mr. Nathaniel D. Thornburg
March 15, 2002
9. Sheet RRD 1 contains two different pumps systems. The first is a reuse
irrigation pump station, and the second is a groundwater control pump station.
Clarification has been provided.
10. The number of spray nozzles, model and diameter have been tabulated as
requested, on sheet RRC I.
11. Calculations are included as to how the wetted spray area was determined.
(An exhibit is also included showing these wetted spray areas.)
12. All product information is included for the proposed irrigation'pumps.
13. An operation and maintenance plan has been included for the irrigation
system
14. All reclaimed water piping, valves and appurtenances will be color coded with
purple pantone no. 522, as required in the referenced regulation. The required
information is included in the specifications for the reuse irrigation system, as
well as shown on the construction drawings, in the public education package
and in the O&M plan.
Groundwater:
1. A verbal comment was received requesting additional clarification for the
Groundwater Section on the boundary of the wastewater disposal site with
respect to the proposed construction. This information is being furnished
under separate cover.
We believe this information appropriately addresses all of the comments received on this
project to date. Five copies of amended plans, specifications and supporting
documentation are included herewith for your review. Please let me know if you need
any additional information in order to complete the review.
Sincerely yours,
Bissell Professional Group
4MS. )issell
Principal
MB/lvk
Encl.
cc: Ray E. Hollowell, Jr.