HomeMy WebLinkAboutCorrespondence: Engr'g Dept Memo Conn, Angelina V (Cl,tly k:x,< x, e nq IDept:., (Memo)
From: Foley, Amanda J
Sent: Thursday, August 30, 2012 12:01 PM
To: Conn, Angelina V
Cc: Duncan, Gary R; Thomas, John G
Subject: 146th and Gray Road gas station memo to Plan Commission
The current configuration shows the entrance drive on Gray Road shifted farther to the south then was previously
submitted, creating a more acceptable distance from 146`h Street. This appears to be the farthest south that this drive
can be located and still include a 100'decal taper and a 30-foot entrance radius. A traffic study was submitted to the
Engineering Department for this project. Scenarios were analyzed that include the Gray Road entrance as a full access
intersection. The traffic study indicates that traffic levels will slightly increase on Gray Road for this use, but the level of
service for the Gray Road/1461h Street intersection will not be significantly affected. The Engineering Department is
satisfied with the currently shown full access drive on Gray Road. Previous projects have indicated an extension of the
right-turn lane at the signal to the proposed entrance on Gray Road which is not shown on this project.
There are currently not any plans for the City to improve Gray Road in this area in the near future. When this portion of
Gray Road is reconstructed,we would anticipate a cross section similar to that found on Gray Road just south of 106`h
Street. The Thoroughfare Plan requires the dedication of a 75-foot half right-of-way width along Gray Road. The current
plan for this project is only showing a 50-foot half right-of-way. Since Gray Road is a Thoroughfare road,the developer
would be required to either construct the improvements required by the Thoroughfare Plan, across the frontage of the
property on Gray Road, or make an agreed upon financial commitment to the Thoroughfare Fund for these
improvements. The developer has already submitted a cost estimate for the improvements on Gray Road that appears
to be accurate.
This project falls within a wellhead protection area. Therefore, no storm water infiltration practices will be allowed on
site, per Indiana Administrative Code 327 15-13-16(c)(1). Any storm water facilities must be lined to prevent infiltration
per the City's Wellhead Protection Ordinance or as approved by the Local Planning Team. In previous cases involving
gasoline retail outlets within the Wellhead Protection Area,the Engineering Department has required extra levels of
treatment for storm water runoff from the fueling area, and storm water modifications to the storm drain system
conveying this runoff. The Engineering Department would require the fueling area to be graded to drain internally,with
any runoff being directed to storm structure Best Management Practices that can remove lead, copper, zinc, and
polyaromatic hydrocarbons. Additionally, all on site storm water is required to be treated by a minimum of two storm
water quality best management practices, as well as, meet the City's standards for detention. Storm piping would have
to be modified to sanitary grade pipe and pressure tested to ensure there is no potential for exfiltration of runoff into
surrounding soils. Storm Structures designed to store pollutants would also have to be lined. In case of a catastrophic
spill, a "shut off"valve will also have to present on the downstream end of the storm system and the parking area will
have to be able to contain 110%of the volume of the largest fueling tanker expected to be on site.
It appears that there is at least one drainage channel and possible wetland areas along the southern portion of the
parcel. A water resources study will need to be conducted and any alterations approved by the USACE and IDEM if there
are proposed impacts to a water resource. If no impacts are proposed, a water resources study should be completed to
determine which areas require buffers per Chapter 700 Section 7.05 of the Subdivision Control Ordinance.