Airport Master Plan 2012 - City of Waterville

China Lake as its sole source of supply. It filters and treats the China Lake water in its Vassalboro
filtration facility, a state-of-the-art plant placed online in August 1993.
For purposes of previous stormwater management analyses, four watersheds were identified within the
Airport property. 5 Runoff from three of the watersheds on the site (Watersheds 2, 3 and 4) is directed to
the southeast via a series of drainage-ways within the southeastern portion of the site. Stream flow enters
the Lower Kennebec River approximately 6,000 feet southeast of the Airport. The Lower Kennebec
River is a sensitive and threatened watershed. 6 Watershed 1, contains the business park and the northwest
portion of the Airport. Runoff within Watershed 1 enters a stream channel which flows north to south
within the western portion of the site and also later joins the Lower Kennebec River.
In 2004, permit requirements for upgrades to the Airport apron and automobile parking lot required the
removal of at least 40% of the total suspended solids (TSS) in stormwater runoff to meet the sliding scale
TSS standard. These improvements also involved the use of dry swales to reduce the water temperature
of runoff by passing it through solid filters and undergrounds drain lines. This is intended to help prevent
the runoff from having any thermal impact of the small brook draining to the Lower Kennebec River.
Groundwater
The Airport and the Airport Business Park are situated in an area with moderate to low or no potential
groundwater yield and are not located over or near any mapped sand and gravel aquifer which could be
utilized as a municipal groundwater supply. All current and future development at the Airport will utilize
municipal water supply and wastewater disposal systems. Small quantities of petroleum products or other
potential groundwater contaminants are stored within the T-hangar or cube hangar units 7 . The hangars
are built upon concrete slabs and no floor drains are present. The fueling facility at the Airport is
addressed in a revised Spill Prevention Control and Countermeasure (SPCC) Plan (see Fuel Storage).
Topography and Geology
The Airport and the Airport Business Park are situated on a hill comprised of glacial till with moderate to
low or no potential groundwater yield. The surficial material underlying the Airport property is
designated as Qt (till) which is heterogeneous mixture of sand, silt, clay and stones that generally overlies
bedrock or sand and gravel. The property is primarily comprised of upland soils formed in firm stony
glacial till including Woodbridge fine sandy Loam, Hollis fine sandy loam, Paxton-Charlton fine sandy
loam and Scio very fine sandy loam. Wetland areas within the property are mapped as poorly drained
Scantic silt loam and Ridgebury fine sandy loam. The extent of the hydric soils will be better refined
during future detailed wetland delineations. Future stormwater management structures will involve the
drainage classification and percolation rate of the soil, and the siting of structures will involve the loading
capability of the soils.
Bedrock mapping within the vicinity of the Airport includes stratified rock of the Silurian age,
specifically the Waterville Formation (Sw), the Sangerville Formation (Ss), and an unnamed sulfidic
pelite (Sur).
5
Application for Permit Modification. March, 2004. Prepared by Dufresne-Henry, Inc.
6
State of Maine Department of Environmental Protection SLDA Permit No. L-8253-18-I-M. Page 3 of 7.
7
Spill Prevention Control and Countermeasure Plan. Waterville Robert Lafleur Airport. August 2006. Prepared by Stantec Consulting
Services Inc.
The City of Waterville Maine
Baseline Conditions – Page 1-18
Airport Solutions Group, LLC & The Louis Berger Group, Inc. December 2011