NC0078115_Authorization to Construct_20030624

ATC No. 078115A01
NPDES Permit No. NC0078115
Engineer's Certification
I, J. Thurman Horne, as a duly registered Professional Engineer in the State of North Carolina,
having been authorized to observe periodically the construction of the project, Greystone Forrest
Subdivision Wastewater Treatment Plant, Forsyth County, for the Permittee, hereby state that, to
the best of my abilities, due care and diligence was used in the observation of the construction
such that the construction was observed to be built within *substantial compliance and intent of
the approved pl��;�; at; s.
Signatur�(�`,r;:`[;�//" — Registration No.: 10436
Date
10436 ..r3 O a
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is ®THURMAke+`'
* Note: The facififf'+e'tmplete and operational with only minor landscaping to be completed
by the contractor, including the stabilization, seeding and covering of areas disturbed in the.
course of construction. Inclement weather has delayed the contractor's ability to complete this
item.
RECEIVED
JUL - 1 2003
DWQ STAFF SERVICES

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E., Director
November 1, 2002
Mr. Dusty Metreyeon
AquaSource, Inc.
107 Commercial Park Drive
Concord, North Carolina 28027
AVA
NCDENR
Subject: Authorization to Construct
ATC No. 078 1 15A01
NPDES Permit No. NC0078115
Greystone Forest Subdivision WWTP
Forsyth County
Dear Mr. Metreyeon:
The Division of Water Quality's NPDES Unit has reviewed your request for an Authorization to
Construct a new wastewater treatment facility at the Greystone Forest Subdivision WWTP. The
Division finds the proposed improvements and design to be satisfactory and hereby grants
authorization for construction or installation of the following:
• an influent pump station with duplex feed pumps (56 gpm each at 29 ft. TDH);
• a 16,030 gal. flow equalization tank with duplex feed pumps (22 gpm each at 15 ft.
TDH);
• a dual -train, extended aeration package treatment plant (30 hrs. HDT at average daily
flow) with influent flow splitter box and integral clarifiers;
• four (4) - 90 cfm centrifugal blower/motor units;
• an 11,000 gal. sludge treatment and holding tank; and
• all related structures, equipment, piping, controls, and other appurtenances, in
accordance with the proposed plans and specifications.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of NPDES Permit
No. NC0078115, issued December 23,1996, and modified August 23, 2002, and shall be subject to
revocation unless the wastewater treatment facilities are constructed in accordance with this ATC
and the conditions and limitations specified in the NPDES permit.
Upon completion of construction and submittal of an acceptable Engineer's Certification (see below),
the approved design capacity of the facility shall be 0.032 MGD.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer On the Internet at http://h2o.enr.state.nc.us/NPDES

ATC No. 078115A01
Greystone Forest Subdivision WWTP
The Permittee shall maintain a copy of the approved plans and specifications on file for the life of
the facility.
If you have any questions about this Authorization to Construct, please contact Mike Templeton, at
[phone], extension 541.
Enclosures: Engineer's Certification Form
Copies:
Sincerely,
Alan W. Klimek, P.E.
Director
Mr. J. Thurman Horne (w/ enclosure) - • Horizon Engineering & Consulting
107 Commercial Park Drive •
Concord, NC 28027
Winston-Salem Regional Office, Water Quality
Technical Assistance and Certification Unit
Central Files
NPDES Unit Files -

ATC SUMMARY
AquaSource, Inc.
Greystone Forest Subdivision WWTP
ATC No. 078115A01
Belews Creek, Class C
Roanoke River Basin
Forsyth County
SCOPE
AquaSource, Inc. proposes to replace the existing 0.040 MGD Greystone Forest Subdivision WWTP with
a new 0.032 MGD plant of similar design. The proposal is consistent with a Preliminary Engineering
Report submitted in 2001 and found acceptable by the Division.
RECOMMENDATIONS
1. Approve the ATC request, received June 5, 2002.
PROTECT DESCRIPTION
The proposed improvements consist of:
• an influent pump station with duplex feed pumps (56 gpm each at 29 ft. TDH);
• a 16,030 gal. flow equalization tank with duplex feed pumps (22 gpm each at 15 ft. TDH);
• a dual -train, extended aeration package treatment plant (30 hrs. HDT at average daily flow)
with influent flow splitter box and integral clarifiers;
• four (4) - 90 cfm centrifugal blower/motor units;
• an 11,000 gal. sludge treatment and holding tank; and
• all related structures, equipment, piping, controls, and other appurtenances, in accordance
with the proposed plans and specifications.
The proposal calls for installation of a new influent pump station and package plant. An existing
package plant from another site will be modified to create the flow equalization basin and the sludge
treatment/ holding tanks.
These treatment units from the existing plant will remain in service:
• flow splitter box (with modifications),
• post -aeration,
• chlorine contact, and
• effluent flow measurement.
No back-up power is required due to influent lift station and well water supply to the community.
REVIEW NOTES
Influent Pump Station - Each pump is sized to handle 2.5 times the ADF. OK.
Equalization - Operating volume is 12,620 gallons, not the 16,030 gallons shown (total volume). Still
gives 40% of ADF @ 32,000 gpd, 32% @ 40,000 gpd. OK.
Aeration Basins - Operating volume is approx. 38,400 gal, giving a HDT of 1.2 days (28.8 hrs.) at 32,000
gpd [23 hrs. @ 40,000 gpd]. OK for extended aeration mode at 32,000 gpd.
Froth Control Lines - Not clear what source of water is used.
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ATC Summary (cont.)
AquaSource, Inc.
Greystone Forest Subdivision WWTP
ATC No. 078115A01
Clarifiers - Surface area is approx. 200 ft2, giving a SLR of 160 gpd/ft2 at ADF, 400 at PF of 2.5. OK.
Assuming sludge blanket occupies' of cone volume, useful clarifier volume is approx. 3,595 gal, for
HDT of 2.7 hrs. at ADF. OK.
Sludge treatment/ holding volume is approx. 10,000 gal. (w/ WL at 8'6"D, same as opening between
chambers). This is equivalent to 4.2 ft3/capita, assuming 100 gpd/cap. >3 ft3/cap, so OK.
Flow splitter is from the existing WWTP and will be modified to return excess flow to the equalization
basin.
Review does not include evaluation of existing units.
Other comments and concerns were relatively minor and were not addressed further during the review.
The drawings show the same elevation for two of the float switches in the pump station. I passed this
along to the engineer but did not mention it in the ATC itself.
- end of summary -
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