Airport Master Plan 2012 - City of Waterville

2, 3 and 4 are located on airport property around Taxiway „D.‟ Watershed 2 generated runoff drains
northerly off airport property. Runoff in Watershed 3 drains westerly to a drainage ditch before leaving
the Airport property. Runoff in Watershed 4 drains southerly to a wide, shallow swale and then leaves
airport property. All three Watersheds 2 through 4 eventually drain to the same stream that drains
Watershed 1. The stream in turn empties into the Kennebec River at a location about 1.5 miles in a
eastern direction from the Airport.
It was determined in the environmental permit referenced above, that the proposed reduction in pavement
from Runway 14-32 will mitigate any increases in on-site stormwater runoff resulting from previously
identified airport projects, including T hangars in the vicinity of taxiway “D”. At that time, it was
determined that the proposed development met the standards for stormwater management. However, since
the projects identified in the 2004 permit do not exactly match those of the current proposed improvement
projects and some of the proposed development specified in the 2004 permit application has not occurred,
the proposed improvement projects will be subject to future determination and/or require an additional
Application for Permit Modification that identifies if the proposed projects meet the current Maine DEP
standards.
The impacts to pervious surface related to all proposed development result in the addition of
approximately, 218,000 SF of pavement. These projects include:
A new taxiway “E” which will connect taxiway “D” to taxiway “A”;
An aircraft apron adjacent to the existing terminal apron;
FBO building development abutting the new aircraft apron;
A SRE building in the vicinity of the existing terminal; and
T hangar development.
Alterations to stormwater flow at the Airport could result from increasing the amount of impervious
surface, however, the proposed narrowing of Runway 14-32 would offset this by approximately 165,000
SF, and the reclamation of the abandon pavement in the east quadrant of the Airport would additionally
offset this by approximately 140,000 SF. Therefore, the construction of all proposed development in
conjunction with pavement removal results in an additional pervious surface of approximately 87,000 SF,
or nearly 2 acres, which could result in improving the overall drainage at the Airport.
It is anticipated that as airport projects progress, the impacts of additional impervious surface will
concurrently be offset by the narrowing of Runway 14-32 and/or the removal of the abandoned pavement.
Furthermore, with the addition of the dry swale west of the proposed development along taxiway “D”, it
is also anticipated that the required total suspended solids (TSS) removal standards associated with
proposed development will be met. Actual stormwater impacts will be investigated further, and
determined in a subsequent environmental analysis.
5.5 U.S. Department of Transportation Act Section 4(f) Land
It appears that no adverse impacts to Section 4(f)/6(f) properties (publicly owned parks, recreation areas
or wildlife refuges) will occur as a result of the preferred alternative and, therefore, no measures to
mitigate potential impacts resulting from the proposed action appear warranted.
The City of Waterville Maine
Environmental Review – Page 5-5
Airport Solutions Group, LLC & The Louis Berger Group, Inc. December 2011