Re: The inappropriate location of three new gravel pits adjacent to Big Hill Springs:
Bighill Creek Preservation Society (BCPS) was associated in 2015 to protect and preserve the natural, archaeological and historical features of the Bighill Creek watershed. We are particularly concerned about the negative impacts three new gravel pits would have on the source water for Big Hill Springs Provincial Park and the Bighill Creek ecosystem downstream.
The proposed Summit, McNair and Lafarge pits would be located on the aquifer which provides the springs which is the raison d’etre for the Park. (See attached Map BCPS Big Hill Springs Aquifer and Gravel Pits). The pits would remove protective overburden and expose up to 480 acres of the aquifer to contamination and operational de-watering. Applications for these pits are currently under consideration by Rocky View County (RVC).
BCPS is of the opinion that gravels sought by these three companies are common in the area and exist in two large swaths across the northern regions of RVC. It is therefore unnecessary and inappropriate to allow extraction which puts at risk a nationally unique set of Springs and a coveted and heavily used Provincial Park.
Below is a summary of the reasons why BCPS opposes the current site proposals for these three pits.
- Unique Attributes of Big Hill Springs
- Listed in surveys for Alberta’s Environmentally Significant Areas studies, as being of national significance due to unique limestone formations and because of their consistently high and even temperature flows, throughout the year.
- Flow rate of the Springs is higher than that of other nearby springs arising from the Paskapoo geological foundation.
- According to a 2007 Geology Department study from the University of Calgary (attached), the spring’s water arises from fluvial deposits mostly just above the Paskapoo bedrock, and from a recharge area of about 31 square kilometers that trends NW and includes lands under the three proposed gravel pits.
- This recharge area produces a measurable enhancing effect, likely due to several ancient (preglacial) bedrock channels feeding into the aquifer. It is thus known as an “enhanced recharge”, something rather uncommon.
- The Springs contribute a majority of flow into Bighill Creek, supporting the diverse riparian habitat between the Park and the confluence with the Bow River.
- The Springs at the Park make a significant contribution to the water quality of Bighill Creek. BCPS’s 2016-2017 water analyses indicate water quality in Bighill Creek upstream of the Park is of considerably poorer quality prior to dilution by water emanating from the Park.
- Big Hill Springs Provincial Park – Already under stress
- This park was established in 1963 as a 63 acre “point of interest” educational and nature appreciation park. It soon drew so many visitors from nearby Calgary as to show almost immediate deterioration, deterioration that continues today due to tens of thousands of annual visitors.
- Pit operations; with their attendant noise, air pollution, possible aquifer impact and dangerous roadway (Highway 567) congestion will diminish the Park experience for visitors and degrade habitat. This little park needs fewer, not more stresses.
- Adjacent gravel pits are inappropriate for site
- High impact industrial uses of adjacent lands are inappropriate for the sustainability of a unique set of springs and for a highly valued and much used Provincial Park.
- The pits are proposed on one of two extensive gravel/sand deposits occupying wide swaths of RVC land. These same aggregates are accessible from many local but less sensitive lands.
- The aggregate layer targeted by the three pit proposals is 10-20 m of permeable sands and gravels, overlain by a less permeable cap of 4-6 m of silts, clays, sands and gravels. Once this cap is removed, the exposed permeable layers will open the aquifer to contaminates.
- On-site contaminates from fuels and other petroleum products used during extraction, and agrichemicals that can leach into new pits from nearby farmlands, will have little chance of being filtered out before reaching the Big Hill Springs due to the short distance between the pits and the spring’s aquifer.
- The draft Aggregate Resource Plan for RVC emphasized environmental responsibility in new gravel pit sitings. We assume the final document, long in revision, will be stronger still in environmental protections.
BCPS asks RVC:
- That these three gravel pit proposals be reassessed in light of their potential impacts on a unique and important water source, on a publicly valued provincial park, and for their potential impact on the Bighill Creek watershed.
- That the pit’s owners be helped to re-locate to more appropriate locations within RVC.