20080069 Ver 1_Staff Comments_20080516

08-0069 TownePlace Suites
AML comments
May 16, 2008
1. On this site, you are required to have a best management practice (BMP) that
removes a minimum of 85% of the TSS from all stormwater generated by the
TownePlace Suites property. As described in a meeting between the consultants
(Tom Spaight and Lance King) and DWQ staff (Cyndi Karoly, Richard Jones and
Annette Lucas), we see two logical options for achieving the required stormwater
treatment on the site:
a. Option 1: Provide BMPs on the site that will remove 85% of TSS. These
BMPs must be designed per the most recent version of the DWQ BMP
Manual. BMPs that would meet this requirement include infiltration
trenches, sand filters and bioretention areas. For each BMP that is
proposed, you must provide a BMP Supplement Form (including both
worksheets, Design Summary and Required Items Checklist), as well as
all of the required items. The BMP Manual and Supplement Forms are
available on the DWQ web site at:
http://112o.eni-.state.nc.us/su/bmp forms.litm.
b. Option 2: Provide a properly designed Stormceptor device on the site.
The design of the device, along with a detailed operation and maintenance
agreement and a monitoring plan, must be submitted to DWQ for review.
The Stormceptor will have to be monitored for one year and at the
conclusion of that year, if the device fails to consistently remove a
minimum of 50% TSS, then the device will have to be replaced with
another BMP that has been designed in accordance with the DWQ BMP
Manual. In addition, Option 2 will entail bringing the existing dry
detention pond (that currently serves the entire 28-acre development)
closer to current design standards by providing a properly designed
forebay at the inlet structure that receives the runoff from the TownePlace
Suites property.