HomeMy WebLinkAboutWPO201700048 Correspondence 2021-07-22 (3)® COLLINS ENGINEERING
July 14, 2021
Frank Pohl, P.E.
Community Development
Engineering Department
401 McIntire Road
Charlottesville, VA 22902
RE: Old Trail Creekside III, Phase II —WPO 2017ODD48 (Amendment #1 to WPO 201200008)
20o GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
��434.293.3719 PH 434.293.2913 FX
www.coll ns-eng ineeri ng.com
Thank you for the comments dated July 31, 2017 on the above referenced project. These comments have been provided with this
submission for the reviewer's convenience. Below is a summary of how the comments have been addressed. The applicant has also
attempted to provide a summary of this project's history for the benefit of the reviewer.
Engineering Comments:
A. Stormwater Pollution Prevention Plan (SWPPP)
1. N/A
B. Pollution Prevention Plan (PPP)
1. N/A
C. Stormwater Management Plan (SWMP)
1. This comment is acknowledged. Following this submittal, the nutrient credit amount can be finalized with County
Engineering's consent and the developer can proceed with the nutrient credit purchase.
2. The plans have been revised and no loner propose SWM forest and open space easements, hereby making this comment no
longer applicable.
D. Erosion & Sediment Control Plan (ESCP)
1. N/A
Summary of this Project's History
1. The original WPO 201200008 plan for Old Trail Creekside III, Phase II was approved on 5/16/12. Water quality was provided with a
biofilter and a pro -rats share contribution. Water quantity was met through attenuation in the biofilter and an adequate 9' wide
riprap lined channel through a "MS-19 X-Section" to Lickinghole Creek's bank, where "th _
o" - contributing drainage area" (as noted on the last page of the set, sheet 1 of 1).
2. In the attached 3/30/17 e-mail chain, it was determined the biofilter could be replaced with a nutrient credit purchase in an
amendment from a water quality standpoint. The amendment's nutrient credit purchase would be 70%of the required
phosphorous removal rate since guidance on 9/19/14 stated " unt,,
pollutant load leaving the site." This e-mail chain also determined the detention waiver associated with this project (but not
utilized) would no longer be valid from a water quantity standpoint with an amendment removing the biofilter.
3. On 6/8/17 CE submitted an amendment removing the biofilter. From a water quality standpoint, the amendment proposed SWM
forest and open space easements/credits and a nutrient credit purchase. From a water quantity standpoint, the amendment met
channel protection requirements via 9VAC25-870-66 subsections B.1.a and B.4.a (2-yr is not erosive to a point of 1%). The flood
protection requirements were met via 9VAC25-870-66 subsections C.2.a and C.3.a (10-yr storm is confined to a point of 1%).
4. On 7/31/17 County Engineering issued the attached comment letter and gave the project a new WPO number (WPO 201700048).
5. On 6/8/20 CE resubmitted this amendment addressing the comments, as noted above. This is documented in County View under
WPO 20120DD08. Its the applicant's understanding that the project did not progress further, for reasons unbeknownst to him. It
is possible that the change in WPO numbers caused confusion on the County's behalf, and that the applicant failed to follow up.
6. With this resubmittal CE would like to address the most recent 7/31/17 County comments for an approval, pending the nutrient
credit purchase.
Should you have any questions, please feel free to contact Scott Collins at scott@collins-engineering.com or Graham Murray at
graham@collins-engineering.com .
Sincerely,
Graham Murray, PE