HomeMy WebLinkAboutWPO202000024 Review Comments WPO VSMP 2020-05-24COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
VSMP Permit Plan Review
Project:
Christopher -Shilling Residence - VSMP
Project file#:
WP0202000024
Plan preparer:
Alan Franklin PE, Waterstreet Studio / 418 E. Main St.
Charlottesville, VA A22902
[alanAalanfranklinpe.com ]
Owner or rep.:
Sally Christopher & Tanner Shilling / 817 Montrose Ave
Charlottesville, VA 22902 [ ranllyshillophergamail.com ]
Plan received date:
20 Apr 2020
Date of comments:
24 May 2020
Reviewer:
John Anderson
In speaking with Cailen von Briesen, 5/21/20, Engineering expressed commitment to review revised plans within 5
business days. A bit more time may be required, given range of comments, but within 10 days is the goal. In the
interim, please consider whether this project will purchase credits, or place areas in forest /open space easement.
County Code section 17-410 and Virginia Code §62.1-44.15:34 requires the VSMP authority to act on any
VSMP permit by issuing a project approval or denial. This project is denied for reasons listed below. The
VSMP application content requirements can be found in County Code section 17-401.
A. Stormwater Pollution Prevention Plan (SWPPP)
The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain
(1) a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary.
1. Complete Certification, p. 7, single family SWPPP.
2. Given scale of project, provide PPP Exhibit that shows: paved CE draining to trapping measure, rain gauge,
solvent storage, stucco /paint clean-up area, concrete washout draining to trapping measure, on -site fueling
with lined containment /berm sized for (stored volume of fuel + 10-yr rain event) x 1.1 (cf), non -hazardous
solid waste dumpster, and portable sanitary facility.
3. Include reference to WP02020-00024 in revised single-family SWPPP title.
B. Pollution Prevention Plan (PPP) — See item 2 above.
The PPP content requirements can be found in County Code section 17-404.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan is disapproved for reasons listed below. The stormwater management plan content requirements can be
found in County Code section 17-403.
1. SW.100
a. If (nutrient) credits are not available and a portion of the parcel is placed in forest /open space
easement, easement deed and Maintenance Agreement must be recorded prior to VSMP plan
approval.
b. Design proposes concentrated (piped) discharge to each ELS; provide:
i. V2-yr calculations
Note: each LS sizing worksheet assumes 5 fps within pipes. This may be erosive.
Engineering Review Comments
Page 2 of 4
ii. Outlet protection, each ELS (1 — 4). Specify L x W x D outfall protection. Specify size
(Cl. 1 riprap, etc.). Ensure velocities non -erosive at each ELS.
iii. Specify VDOT end sections for each outfall pipe.
iv. Provide profile for each outfall pipe.
v. Ensure sufficient cover.
vi. Check for conflicts.
c. Outfalls to LS
i. Label pipes: 1, 2, 3, 4 (or similar).
ii. Provide pipe L, DIA ( similar to EC.102).
d. Label residence, pool, pool house, garage, barn, parking, drive, etc.
e. Recommend either permanent inlet protection, culvert B, or provide plan notes that emphasize
need to maintain inlet protection at culvert B until barn drive ditch is completely stabilized.
f. Provide V2_n barn drive ditch which conveys runoff from Zack Lane, over a 20' vertical interval.
Provide soil stabilization blanket /similar, if needed.
g. Notel: Nutrient purchase requires coordination with county (Ana Kilmer /tel. 434.296-5832 -
x3246) prior to executing purchase documents since project specific information must appear in
documents (Affidavit, bill of sale).
h. Note2: Nutrient purchase must be completed prior to receiving a grading permit. In speaking with
Cailen von Briesen, 5/21/20, speed is an objective, with project approval /grading permit as soon
as possible. Either SWM water quality compliance strategy involves process: either purchase of
nutrient credits or platting /recording Forest/Open Space Easement. Engineering supports either
approach, consistent with program requirements. It is not too soon to initiate either process, either
by exploring nutrient credit availability, and contacting Ana Kilmer, or committing to plat an area
as Forest /Open Space Easement. An easement requires separate county application, fee, and
review schedule that will add considerable time to grading permit issuance, likely, several months.
Nutrient purchase may be a quicker path to grading permit issuance.
2. Include Construction Record Drawings (As -built) for VSMP on the plans; link:
hqp://www.albemarle.org/upload/ima2es/forms_center/departments/Communi1y Development/forms/Engineeringand
_WPO_Forms/WPO VSMP Construction_ Record_ Drawings Policy 23May2014.pdf
3. Include ELS periodic maintenance and inspection guidelines on the plans (see VA DEQ Spec. #2).
4. Include ELS construction installation guidelines on the plans (VA DEQ Spec. #2).
Note: Although ELS are not installed for water quality, they are installed for quantity control, are SWM
facilities, and installation, maintenance and inspection procedures are relevant and must appear on the
plans.
5. 17-414 requires bond for ESC measures.
6. Engineering policy concerning single-family construction has evolved, and Albemarle does not now require
SWM Plan bond for single-family residential SWM facilities, although mitigation plans and ESC measures
do require bond. Although SWM facilities (ELSs) will not be bonded, ESC plan bond may not be released
until ELSs are accepted. See item 2, above. An as -built drawing is required for each ELS.
7. A state permit is not required for single-family construction. (VAR10 CGP).
D. Erosion and Sediment Control Plan (ESOP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan
is disapproved for reasons listed, below. The erosion control plan content requirements can be found in
County Code section 17-402.
1. Sign /seal plans.
2. Include reference to WP02020-00024 in plan title.
3. Depict existing conditions; provide existing conditions sheet.
4. Provide Stage 0 ESC Plan (1" =40' scale) that shows perimeter controls prior to clearing, or constructing
improvements, consistent with construction sequence.
May combine 3 and 4; i.e., existing conditions w/perimeter ESC controls /paved construction entrance
(PCE).
Engineering Review Comments
Page 3 of 4
5. On Stage 0 ESC Plan:
a. Show property boundary and label TMP #59-37D (Also, note, below).
b. Provide ownership data for TMP#59-37D.
Note: SW.100 indicates boundary line adjustment (BLA) will combine TMP 59-37C4 and -37D.
BLA plat must be recorded prior to VSMP /WPO plan approval unless existing TMP 59-37D
boundaries are shown. Also, timing of BLA may affect nutrient purchase or format of Forest
/Open Space Easement. Please provide status on BLA application (submitted, reviewed, etc.).
c. Show and label critical slopes. Use easily distinguishable hatching.
d. Show /label ponds (image below).
e. Stage 0 will not show proposed improvements. Once existing conditions, distances, slopes to SF
perimeters are more nearly visible, Engineering anticipates one or more sediment traps will be
needed. This 4.30 Ac. disturbance likely cannot be managed without diversions and sediment
traps.
f. If traps are required, provide required ST design data, including trap floor /weir dimensions, etc.
6. EC.141
a. Revise steep slopes label to critical slopes, since project is in the rural area.
b. LS labels reading L.P. ELEV 531.5', for example, are unclear. Please clarify L.P.
c. Provide roof /garage /barn leader line connections to piped systems. If roof discharge is to
surface, label discharge to splash blocks. Consider erosion potential. Engineering recommends
roof runoff collection with conveyance to piped systems.
(Evaluate /consider critical slopes susceptibility to erosion.)
d. Label temporary outlet protection dimensions at SE corner of lawn (L x W x D).
e. Revise LS3 discharge pipe to 8" DIA.
EC.103 /Level spreader -Typ. detail
a. Include schematic representation of the ELS structure, concrete or timber.
b. Provide x-sectional dimensions (L of each of 4 ELSs varies).
c. See VA DEQ Stormwater Design Specification No. 2, FiT2.3, below.
d. Include underdrain in EC.103 detail to prevent ponding /nuisance conditions; ref. Fig 2.3.
e. Daylight ELS underdrain/s.
(Although EC.103 detail is descriptive, it lacks structural element and underdrain.
Recommend label EC.103 L.S. detail ( x 4)).
Engineering Review Comments
Page 4 of 4
Level 5preader Lp
3' Layer of
Now Path.- 157 Stone
� Rlpaflil Bufflf
Or F12w S&V
1
Channel
3 ft Mae
Underdram - 5aed
` Strip of
For Site Sod
Filtar Fabric
Conditiom - Dram
Appropriately 51zed
Into 13ypa55 Swale
Concrete Footer
Figure 2.3: Plan and Cross Section of Engineered Level Spreader (ELS)
(Hathaway 2006)
Version 1.9, March 1, 2011
Page 5 of 20
The VSMP permit application and all plans may be resubmitted for approval when all comments have been
satisfactorily addressed. Please provide digital version of revised plan /SWPPP with a completed application form.
Process:
After approval, plans will have to be bonded. The bonding process is begun by submitting a bond estimate request
form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and
check parcel and easement information based on the approved plans. The County's Management Analyst will
prepare bond agreement forms, which will have to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will have to be approved and signed by the County
Attorney and County Engineer. This may take 2-4 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements will also have to be completed and recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will have to be submitted along with court recording fees.
If nutrient credit purchase is required, purchase documents must be executed prior to county issuance of a
grading permit.
Note: If forest /open space easement is required, plat /deed approval and recordation, which entail separate
processes, must be complete prior to plan approval.
If a boundary line adjustment is pending then BLA approval processes, including plat review and
recordation, must be complete prior to plan approval, or existing parcel boundaries must be shown on the
plan, consistent with current real estate records.
After Maintenance Agreement, forest /open space easement BLA plat (as needed) are recorded, nutrient credits
purchased (as needed), and ESC Plan bond posted, Albemarle can hold a pre -construction conference. Applicants
must request a pre -construction conference (by completing form), and pay any remaining application fee. The form
identifies the contractor and responsible land disturber, and fee remaining to be paid. This will be checked by county
staff, and upon approval, a pre -construction conference will be scheduled with the County inspector. At the pre -
construction conference, should everything proceed satisfactorily, a grading permit will be issued by the County so
that work may begin.
County forms can be found on the county website forms center under engineering;
hLtp://www.albemarle.org/deptfonns.asp?department--cdengmTo
WP0202000024_Christopher-Shilling resid 052420