Water Quality Concerns
Background for Paris Pit Appeal 2016
“The first barrier to the contamination of drinking water involves protecting the sources of drinking water.”
Justice Dennis O’Connor : Walkerton Inquiry 2002
- The overall water quality concern is that the combination of the planned operational activities will permanently change the pollution risk status of the Paris Town wells from the existing rating of high vulnerability to an actual extremely vulnerable
- facilitate the mobilization of agrochemical residues into the aquifer both during and after aggregate extraction
- expose the Paris Town wells, the Grand River and Brantford City water intake to unnecessary and avoidable serious risks to the raw water quality
- expose the on-site natural pond and wetland habitat of species at risk to serious ecological impact.
The location of the site is a primary factor
The 260ha Paris Pit site is located on either side of Watts Pond Road, just north of Paris in the County of Brant.
The site is located on an aquifer rated as high intrinsic vulnerability.
Ground water flow is North West to South East with cold water discharge to the Grand River.
Most of the site is within the wellhead protection areas (WHPAs) of the Paris Town wells.
The Paris WHPAs are rated at the highest level of vulnerability to surface contamination.
The proposed source pond and settling Pond abut the WHPAs and are up-gradient of and abutting the natural ponds and wetlands, the Intake Protection Zone (IPZ) of Brantford City water intakes and the Grand River.
The site was licensed for aggregate extraction in 1974 with minimal licence conditions.
The site licence allows the extraction of 997,000 tonnes per year. The pit life is expected to be approximately 30 years.
No Environmental Impact Assessment was required.
At an Ontario Municipal Board hearing at that time Paris Town Council was not allowed to present concerns on the potential impact on the town wells, the site being then in the Township of South Dumfries.
The site is currently owned by Dufferin Aggregates, formerly a division of Holcim International but now part of CRH.
Although licensed since 1974, Dufferin announced its intention to commence operations at a public meeting in February 2012.
The land has been in continuous agricultural production, predominantly for corn, soya and grains with the use of herbicides. The use of nitrate fertilizers has led to elevated levels in the groundwater affecting some of the town wells.
Under the Source Protection Plan the application of pesticides in a wellhead protection area is a prescribed threat with specified controls. However, the previous use of pesticides has not been included as a prescribed threat.
The site location combined with an unknown level of pesticide residues in the overburden is a major concern.
2.0 Activities of Concern
2.1 Removal of Ground Filtering Capacity in WHPAs
The pit site is fully within an area of high intrinsic vulnerability with most of the site within the WHPAs for Paris town wells. The WHPAs are rated at the highest vulnerability score. The site abuts and is up-gradient of an Intake Protection Zone (IPZ) for Brantford City water intakes.
Between 10 and 15 metres depth of aggregate will be extracted down to 1 metre above the water table across the site. This extraction will create a vast transport pathway, very significantly and permanently increasing the risk of surface contamination to the already highly vulnerable aquifer.
The extraction is permitted under the 1974 licence issued by the MNR. The MNR has refused requests by Brant County Council and CCOB for the licence to be revoked.
Since March 2010 the Lake Erie Region Source Protection Committee has been requesting the MOE to recognize the risks to water sources from aggregate extraction.
The latest motion of November 6th 2014 states
“That the Lake Erie Region Source Protection Committee continues [since 2009] to express their concerns with regard to land uses and activities that penetrate the municipal aquifer and or increase the vulnerability of wellhead protection areas or intake protection zones”.
On March 3rd 2015 this motion received the full support of the Chairs of all the Source Water Protection Committees in Ontario
2.2 Aggregate Washing
The initial site plan showed the wash-plant sited within the WHPAs. Following CCOB comments on this in 2012 the processing operation siting was moved to the current proposed location, outside but abutting the WHPAs for the Gilbert wellfield.
The PTTW application requested the excavation of an 80,000m3 source pond in the aquifer to provide the washing water at 13,000m3/day.
600,000 tonnes per year of aggregate will be washed in 72 days.
The washing process will wash off some 24,000 plus tonnes/year of silt and clay.
The silt and clay fraction is the part of the aggregate most likely to have adsorbed pesticide residues
The wastewater carrying the silt and clay from the washer will go to a settling pond where most of the silt and clay with adsorbed residues will collect as sediment.
The settled wastewater carrying any residues released into solution together with unsettled fine particles was, in the original submitted application, to be returned to the aquifer at the source pond. In response to CCOB’s concerns that the source pond will act as a point of discharge direct into the aquifer for contaminants from across the whole 600acre site, a modified design was submitted by Dufferin in 2015. The modification provided for the inclusion of a recirculation pond below the settling pond to enable direct recirculation of wash water, the source pond being used only for filling and topping up the system.
The 32,500m2 settling pond with the floor of the pond at 1 metre above the water table will provide an indirect pathway through leaching.
With a large surface area and shallow depth changes in temperature and pH compared to those in the ground can be expected with consequent increased potential for release of adsorbed residues.
The groundwater flow from below the settling pond is to the natural ponds, the Intake Protection Zone 3 of Brantford City water supply and to the Grand River.
The settling pond sediment with concentrated levels of adsorbed residues will be stored on site and used in site rehabilitation (see Rehabilitation).
40% of the aggregate will be shipped without washing, any residues in the silt and clay fraction being removed with it.
2.3 Exposure of the aquifer
The excavation of the source pond (19,200m2) opens the aquifer to direct access for airborne and surface contamination permanently.
The settling pond at 1 metre above the water table provides a large area (32,500m2) facilitating the entry of washed and airborne contaminants into the aquifer.
The already licensed options to excavate below the water table, if implemented, would create two large exposed areas in the aquifer.
Environment Canada has identified widespread airborne pesticide residue contamination of open bodies of water in Southern Ontario.
EC’s monitoring at Turnbull Lake in the Paris wells catchment area detected 30 pesticide chemicals including atrazine.
2.4 Site Rehabilitation
At the time of rehabilitation the excavation of aggregate will have turned the site into a transport pathway with the water table at only1 metre below the surface.
The 1 metre of cover will provide insignificant filtering capacity for this intrinsically highly vulnerable aquifer.
Under the MNR pit licence the top soil stored in the site berms together with the accumulated sediment from the settling pond is to be used as ground cover in the rehabilitation of the pit.
Both the sediment and the top soil are serious potential sources of contaminants.
Atrazine residues are present in the groundwater at the current depth of 10 to 15m filtering capacity.
The intended return of the site to agriculture with use of the top soil/sediment in combination with the application again of pesticides in accordance with OMAFRA Best Management Practices is of grave concern.
Most of the OMAFRA recommended herbicides carry ground water advisories on their labels; in particular warning against use in areas with shallow water tables.
The climate change impacts already being experienced in the summer months include extended dry periods followed by heavy rain events.
These cycles will facilitate the mobilization of both aged and current residues and rapid leaching to the now shallow groundwater.
Once in the groundwater degradation of the residues is reduced and persistence increased.
3.0 Pesticide Residue Concerns: Atrazine & Glyphosate
The concern that the combination of the planned operational activities will facilitate the mobilization of agrochemical residues into the aquifer, both during and after aggregate extraction, is based on the increasing scientific understanding of pesticide residue health impacts at low concentrations, their role as endocrine disruptors and their environmental persistence and behaviour.
Atrazine is identified by Environment Canada as inherently toxic to humans and non-humans and in the top 100 most persistent organic pollutants (POPs). Atrazine is ranked highest of 83 pesticides in the Agriculture Canada priority scheme for potential groundwater pollution.
With clear evidence of endocrine disrupting activity it has been rated as a Category 1 substance of high exposure concern by the European Union.
The combination of atrazine’s demonstrated persistence in excess of 20 years with its endocrine disrupting capability, including combined impact with other ED substances, at low concentrations has been acknowledged in Europe.
Its use has been banned in Germany since 1994 and throughout the European Union since 2004. It has been banned in Switzerland, its country of manufacture, since 2005.
In Canada and Ontario the drinking water standard, (maximum acceptable concentration), for atrazine is 5.0ppb (parts per billion) It is an interim standard (IMAC) dating from 1993 and currently under review by Health Canada.
For aquatic life the Canadian guideline at 1.8ppb is more stringent than for drinking water.
In contrast the European Union drinking water standard is 0.1ppb for any single pesticide including atrazine and 0.5ppb for total pesticides.
The EU standards recognize the emerging epidemiological evidence and in particular the latent effects of EDS exposure, particularly in women and children.
Recent South-Western Ontario studies on atrazine and breast cancer cluster by Canadian researchers were cited by the American Public Health Association in its call for stronger prevention strategies including changes to the U.S. standard of 3.0ppb.
In Canada there is no limit for total pesticide concentration, each can be present to its own designated MAC : hence the concern for the cumulative effects.
Water quality standards are active substance (AS) based whereas some pesticide formulations, including Round Up, have been shown to be many times more toxic than the tested active substance e.g. the Glyphosate in Round-Up. Single AS based standards provide inadequate protection.
The interaction between chemical residues can cause additional and/or synergistic toxic effects, again making single AS based standards inadequate.
Despite the Walkerton Inquiry recommendations :-
The Ontario DWQS have not been kept up to date.
Old MACs and interim MACs dating from 1980s.
There is no limit on cumulative total of pesticides in drinking water.
4.0 The Natural Ponds, Wetlands and Streams.
There are natural ponds and wetlands within the site boundary outside the extraction limit. The settling pond site is 100m from the natural ponds.
The ponds and wetlands are described by MMM Group in a January 2015 ecology report for Dufferin:
“The habitat in Q2 [ the ponds and wetlands] was evaluated to determine its sensitivity designation (i.e. low, medium or high) based on the wildlife observations and habitat present.
Q2 [ the ponds and wetlands] has been given the sensitivity designation as Very High
due to the numerous observations of [Species At Risk] SAR (Eastern Wood Pewee, Least Bittern, Milksnake and Snapping Turtle) and rare species along with a very high diversity of birds, herptiles, [snakes] butterflies and odonates [dragonflies] and quality of the wetland habitat”.
Q2 [ the ponds and wetlands] has potential to qualify as Significant Wildlife Habitat
according to the MNRF Significant Wildlife Habitat Guide (2000) for Eco-region 6E, as it functions as amphibian wetland breeding habitat and marsh breeding bird habitat.”
The PTTW and ECA applications were submitted in 2013 before completion of the full ecology study.
It was not made available to CCOB until October 2015, long after the closing dates for public comment on both the PTTW and ECA.
5.0 The PTTW and ECA approvals were issued on the 29th October 2015.
The Environmental Review Tribunal has granted CCOB and the County of Brant leave to appeal specified conditions of the Permit to Take Water and the Environmental Compliance Approval issued by the Ministry of the Environment and Climate Change.
The conditions now being appealed relate to the quantity of water that can be taken and the measures required to prevent and control risks to the groundwater.