20061331 Ver 1_More Info Received_20061016

Mitchell Environmental P.A.
October 13, 2006
Mrs. Cyndi Karoly
401 Oversight and Express Permits Unit
2321 Crabtree Blvd.
Suite 250
Raleigh, NC 27604-2260
Re: Bucklin Subdivision -Request for More Information
Wilson, North Carolina (Wilson Counn~- Netrse River Basin}
DWQ Project #06-1331
Mrs. Karoly:
Q~c~~oe~p
ocr i s zoos
DtuNR • WATER QUALITY
YVETiANDB MID 8TORMNkITER BRANCH
This letter is in response to your request for more information for Bucklin Subdivision dated
August 28, 2006. The following restates your particular questions with a response to each below.
1. Please show all stream impacts including all fill slopes, dissipaters, and bank
stabilization on the site plan.
As illustrated on the attached sanitan- sewer plan and profile drawing (Sheet no. C1 of ~,
there are no longer am- proposed stream impacts for this project. The original PCN
Application included temporary stream and wetland impacts for the installation of a sub-
surface sanitan' sewer main. The design of this sanitary sewer main has since been
redesigned as an aerial stream and wetland crossing to further minimize proposed
environmental impacts.
2. Please show all wetland impacts including fill slopes on the site plan.
No grading plan has been created for this project. However. a plan and profile sheet for
one of the proposed wetland crossings (Bucklin Drive -Sheet tto. C3 of ~ is provided to
illustrate the extent of proposed fill slopes through illustration of existing grades versus
proposed final road centerline grades. Detailed designs for the Valleyfield Lane wetland
crossing are not complete. However, the relatively flat slopes on this site will ensure a
minimal fill slope for the proposed road crossing. Proposed wetland impact acreages
listed in the previously submitted PCN Application are based on preliminary impact
estimates and include a small amount of area in excess of what is actually anticipated to
construct the proposed wetland crossings. You can be assured that constructed wetland
crossings will not exceed the acreages listed in the PCN Application.
3. Please indicate all buffer impacts on the site plan.
All proposed buffer impacts are indicated on the impact maps attached to the original
PCN Application.
4. Please indicate the location of the protected buffers as overlays on the site plan, clearly
showing Zone 1 ar:d Zone 2.
Only one portion of the property that is proposed for development is close to the
protected buffers. This portion contains the proposed sanitary sewer stream crossing near
the cul-de-sac end of Bucklin Drive.
602 East .academy Sn•eet, Suite 10 ~ Fucl:~ai~-Y'arina. R'or7h Carolina 27526
U~ce: 919-557-682 Fae: 919-557--1b~13 A~obile.• 919-669-0329

5. Please indicate the diffuse flow pr©vision »~easures on the site plan, applicable
worksheets, and signed and notarized Operation and Maintenance Agreemen~: T{tis
plan may be redesigned to direct flow into flee remaining wetland onsite at non-erosive
velocities.
There are four proposed storm drainage outlets on this site.
Storm Drain Outlets 1 and 2
The drainage plan has been modified to include level spreaders, designed according to
NCDWQ guidelines, at the outlets of storm drainage s}stems that exit from the two cul-
de-sacs on in the west half of the site (Bucklin Drive and Valletifield Lane). These hvo
level spreaders Located at the end of Bucklin Drive and Valle field Lane are illustrated on
the attached site plan (Sheet no. LI of 1). Applicable worksheets and a signed and
notarized Operation and Maintenance Agreement are attached for your review.
Storm Drain Outlet 3
The third storm drain outlet will release concentrated stormwater into an existing ditch.
behind lot 133. Stormwater flows released into the ditch at this point will then flow
through the ditch and discharge into the wetland area behind lot 137. Subsequently, this
stormwater will flow through a wide. heavily vegetated wetland for approximately 500
feet prior to entering the surface waters of Toisnot Swamp and its associated buffers.
Storm Drain Outlet 4
The remaining storm drainage outlet releases stormwater into an existing ditch in the rear
of proposed tot 8. The majorit}- of this ditch ~~-as ruled a linear wetland by Ms. Jean
Manuele and Mr. Mike Horan on March 22, 2006. A small section of this ditch, on the
rear of lots 9 and 10, tivas ruled a modified natural stream and has Neuse Buffers as
illustrated on the site plan. The majorit}~ of flow through this existing ditch originates
off=site, east of London Church Road (see USGS map ire PC?i'Application). This is
further supported b}° the design of the storm drainage system. Note the 30-inch RCP in
front of lot 62 to intercept stormwater flow from this off-site area. The outlet end of this
storm drainage system utilizes a 36-inch RCP which indicates only a minimal increase in
stormwater flow resulting from on-site contributing drainage areas (lots 1-7, ~6-6Z and
portions of Tuts =11 and .i5). As illustrated by the contours on the site plan, this proposed
stone drain s}-stem is extremely flat. Additionally, the ditch varies in depth from 2-feet
near London Church Road to approximately 4-feet near the proposed outlet. The
topography of this site makes the proper design and installation of a level spreader along
this ditch unrealistic. For these reasons, the owner asks that you accept this storm
drainage system as designed.
Thank you for your time spent reviewing these responses. Do not hesitate to call me if you have
any questions or concerns about this project or if you need any additional information to process
this application.
Sincerely;
.e'
Scott Mitchell, PE, LSS

DWQ Project No. i~CP - ~ 3S' ~
DMSION OF WATER 4UALITY -LEVEL SPREADER WORKSHEET
I. PROJECT INFORMATION {please complete the fdkawing information):
Project Name: Bucklin Subdivision
Contact Person: C,~ ~ M; ~~ G t I / Phone Number. i 9 ~ 9) SS'7 - ~/'~ 8 Z
Level SpreaderlD:. #1 @ end of Bucklin Drive
Level Spreader Length 7 8 ~
Drainage Area 1 . 4 5 ac.
Impervious Area (1 _ 5 5 ac.
agaxirnt~rp Fi1tPr StripBuffer Slope ? .._. °~
y~ ~s
Max. Discharge from a 10 Year Storm 5.9 8 ~
Max. Discharge to Level Spreader ~ cfs
FilterStrip/BufferVegetation Medium Ground
Cover
Pre-treatment or Bypass Method Non e
REQUIRED ITEMS CHECKLIST
(perpendicular to flow)
(on-site and off~site drainage to the level spreader)
{on-site andoff-site drainage to the level spreader)
(6°lofot forested, leaf liffier cover, 8°r6for thick ground cover)*
(thick. ground rxn+er or grass, canopied forest with leaf litter
groundcaver)
Initial in the space provided to indicate the folbwing design requirements have been met and supporting documentation is attached. /fe
requiremerrf has not been rrref; atfach en ex~l~n>?~"~?~; ~^f ~°~!h; . ~t ~ ~?^in?t ~, ~ c?pfete stom~water management plan submittal includes
a worksheet for each BMP, design calculations, pia;ts~ ~lrld sic„icYc,u :,u sh:.r~irg a!', St~~Ps and outlet structure details, a detailed
drainage plan and a Easy executed operatro;-~ r4~td rr~~ir+t~„~,,.~A ~1, ; . . ... ... _, ~ ~ ._
.> ,
_.,a...:l1 ...,1.w1.. 4. Ihr awl f, 1 Annn~nrrl Mty+n nlMl~nt
-11.35 Ei •{fit Y 3s) lilt's!; J73 t7fiU YY)II :riSU 34a2i;i _9r7 5:~rzt i. ,..: :.....-na ..rr_ u~~. vi_e _. _.- ~: sr' v..
Hooiit~anis iniiiais
"~~ ~' Level spreader is at least 13 ft. per cfs for thick ground cover ar grass or 1Q0 g per cfs in canopied forest with leaf
fitter.
~~~yY., ~ Pre-Form Scour Holes are on flat slopes only
4=~~.r No structures are bested in protected buffers*
ff bypass method specified in the Draft Level Spreader Design Option Document:
Bypass method is specified (if applicable) and plan detai{s and calculations are provided
r',.~ar;, g,, to !ere! spreader and subsequent filter strip is hydraulically and spatially separate from the bypass
ri. ~~.
No structures are footed in protected buffers.
__......._...._i lull "'licuil~ +v u1>r bypass and outlets are provid@d.
.~,.,...,.. M ._._.,,p,__~
?!ie ?~~?ration and maintenance agreement includes annual erosion and vegetation repair.
-.. --.._-._..--._._...._..,._._ r
The t.+peration and maintenance agreement signed and notarized lay the responsible party ~ pravide~d.
' Love; spreaders in scrips ran t?e use tan skapes of up to 15'Yo an forested area; with -eat littler cover rr on stopps nt Ifn to ~~°f, in prr
with thick araand csav~r t:!' yrxs :t desigrt~t wing tO H.,~, Draft Lev¢f Spr~der Desigrs tlp+~rs Dent. This petantiplf ~ rp~:rirps a
friinbr vartarte~ irl urutected bugcr ansas. Err any event W,e aet,and leva; spreader l.Qieievt b$ nn:cato ~"" ' ^< " p"'`"~`" ~ ~"'""""'
d Itl LVlIC t VI C 1VlC4lCU iJUttCI QICA.

DWQ Project No. D ~o ~ ~s'3 /
DMSIOFI OF WATER QUALITY -LEVEL SPREADER WbRfCSHEET
I. PROJECT INFORMATION ~~~~sse oom~tete the following information):
Project Name: Bucklin Subdivision
Contact Person: S~ tI i1.t;tGL~~ // PhoneNurrther: L9/9) SSA - ~1G9?_
LevelSpreadalD:_ #2 @ end of Valleyfield Lane
Level Spreader Length 1 7 2 ft (perpendicular t4 flow)
Drainage Area 3.2 ~. (on-siteandoff-site drainage to the level spreader)
Impervious Area 1 _ ~ ~ ac. (on~ite and off~ite drainage to tl~e level spreader)
Maxirtrrxn Fitter Stripl8uffer Sbpe 1 _ 4 % (6%for forested, leaf littler cover, 8%for thick ground coverp
grass
Max. Discharge from a 10 Yeeu Storm 1 3.2 0 ~
Max. Discharge to Level Spreader 13.2 0 cfs
FtiterSdiplt3ufferVegetation Medium Ground
Cover
(thick ground cover or grass, canopied forest with leaf fitter
groundcarer)
pre-treafmantor gyps Metlrod None
REQUIRED ITEMS CHEt~I.IST
Initial in Use space prarided b indicate the foNowing design requirements have been met and supporting documentation is attached. !f e
regreremenf has not been ~ attach avr expfanatron of why. At a mirrmum, a rxxnplete stomrwaier maaragenrerrt plan submitfaf inckrdes
a wrxkstreet for each BAP, design calarlations, plans and speafir~tions showing ~ BMPs and outlet structure detar1s, a detailed
drainage ptarr and a fuNy executed operation Bard mairrtenarx~ agneertrent An inrwtrrplete submr Wlk~ package w~ tesuft in a request for
additional itrfortrration and w~ substantialy delay final review and approval of the project.
frcatrl9 Initials
Level spreader is at least 13 ft per cfs for thick ground Darer or grass or 100 ff per cfs in canopied forest with leaf
letter.
~` ~ ^Pre-Form Scour Ffofes are on t>~ slopes only
No s>tuc>lrres are kx~ted in protected bulthrs'
tf bypass method speafied in the Drag Level Spreader Design Option Document
Bypass method is speafied (rf apptic~rle}and pl~r dethr7s and cakxrla6orrs are pn~rided
Discharge b level spreader and subsequent fil6er strip is hydrauticaby and spatially separate from the bypass
~sc~rarge.
No stnrctures are boated in protected braffers.
Plan details for ifre bypass and outlets are provided.
The operation artd maintenance agreement indudes annual erosion and vegetation reparr.
The operatia- and maintenance agreement signed and notarized by the responsthle parhr is provided.
'Level spreaders rn series can tie used on sbpes of up to i3% in forested areas with leaf frttler cwver or on slopes of up b 25%in areas
with thick grand Dover a grass d designed aorxxdng b the Draft Level Spreader Design Option Document Tiffs poter-tiaAy requires a
minor variance b protected buffer areas. In any event the second level spreader cannot be boated in Zare 1 of a protected troffer area.

Operation and Maintenance Schedule for Level Spreaders
for
Bucklin Subdivision
Wilson County, North Carolina
The level spreader is defined as an elongated, level threshold, designed to diffuse
stormwater runoff.
Maintenance activities shall be performed as follows:
1. After construction and until vegetation has been established, level spreader(s)
shall be inspected after every rainfall. Thereafter, level spreader(s) shall be
inspected at least every month and more frequently during the fall season and
after heavy rainfall events:
a. Accumulated sediment, leaves, and trash shall be removed, and repairs made if
required.
b. Inspect level spreader(s) for evidence of scour, undercutting, settlement of the
structure, and concentrated flows downhill from the level spreader(s).
c. A level elevation shall be maintained across the entire flow-spreading structure
at all times. Repair or replace the level spreader if it is damaged.
d. Mow vegetative cover to a height of six (b) inches and prune plants if they
cover over half of the level spreader surface.
e. Repair eroded azeas and replace/replant dead or damaged vegetation.
2. The contractor should avoid the placement of any material on and prevent
construction traffic across the structure. If the measure is damaged by
construction traffic, it shall be repaired immediately.
3. Inspect and repair the collection system (e.g., catch basins, pipes, swales, riprap}
four (4) times a year to maintain proper functioning.
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I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Print name: i~-S~s~~~~__<:~-'~~!?b
Title: ~j~~~, ,
Note: The legally responsible party should not be a homeowners association unless
more than 50'0 of the lots have been sold and a resident of the subdivision has
pb/ee_n named the president.
I, V//C~''1'i/ ~ ~ ~Qi~e , a Notary Public for the State of
~t.lor~h ~lr~o/ir~a ,County of /v100Ye , do hereby certify that
/~Q(x.~~ ~ . ~~~j~0/2?~ personally appeared before me this
day of ~~~I' , 20~ and acknowledge the due execution of the
forgoing level spreader maintenance requirements. Witness my hand and official seal,
SEAL
My commission expires ~-~~"~DO
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