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Moraine Drain Sucks Wells, Streams and Wetlands Dry

Massive York-Durham sewer construction
dewatering of ORM aquifers beside
Rouge stream.

A Brown and Black Metallic Sludge coats
rocks where polluted Sewer Construction
Dewatering discharges to Rouge Streams.

Rural Well deepening cannot keep up with 
the aquifer drawdown caused by the York
Durham Sewer construction de-watering.

Dewatering of ORM Aquifers threatens
to suck the Rouge River dry
(July 30, 2003, Little Rouge River).

Mineralized water from sewer
construction stains the ground red
as it flows to a Rouge trout stream
(September, 2003).

City TV reporter, Bob Hunter, videotapes
low water levels in Little Rouge River in
September, 2003.

The adjacent photo shows dewatering (draining) of Oak Ridges Moraine (ORM) aquifers for the twinning and extension of the York Durham sewer in Markham. This poorly-designed project is draining ORM aquifers that support Rouge Park streams, wetlands and rural wells.

100+ Square kilometre Impact Area

ORM aquifers in an area of approximately 100 square kilometres have already suffered impacts. The impact area stretches from Warden Avenue in the west to the Pickering Townline in the east and from 14th Avenue in the south to the Oak Rodges Moraine in the north. The middle ORM aquifer has already dropped by 40 to 60 metres (130 to 196 feet) in some locations.

Removing 50 Billion Litres of Water

In spite of the growing impacts, York Region has asked the Ministry of Environment to permit a doubling of the dewatering rate to more than 34,000 litres per minute. This represents water removal at a rate that would fill a large background swimming pool every minute. Over the next 30 months of construction, more than 50 billion litres would be removed from ORM aquifers. Further proposed sewer segments, northward along Leslie through the ORM and southward through the Rouge Park, could extend the dewatering impacts for several years.

Servicing 34 More Years of Urban Sprawl

This billion-dollar project is designed to accommodate human waste from the next 34 years of urban sprawl, all the way to Lake Simcoe. However, the project may have to be revised because of the growing impacts to ORM aquifers, streams and wells. Concerned citizens are asking for a thorough environmental assessment to examine alternatives, impact avoidance, mitigation and cumulative effects. Knowledgeable engineers say there are ways to build the sewer that would not require massive dewatering of ORM aquifers.

Harming the Rouge Park, Oak Ridges Moraine and Lake Ontario

If current plans are approved, this huge sewer pipe will tunnel through the ORM and trench through the Rouge Park to send an additional 132 billion litres of treated sewage into Lake Ontario each year. Dumping so much treated sewage into Lake Ontario could further pollute our drinking water source and our beaches and harm public health.

The first phases of construction have already reduced well water quality and dried-up many rural wells in Markham, and the impacts will spread if construction and dewatering continues. Many Rouge streams and wetlands that provide habitat for rare species of fish and birds are in danger of drying-up. A few Rouge streams would receive huge amounts of polluted water discharge, creating erosion and harm to trout habitat and aquatic life.

Difficult to Detect or Fix Leaks

Installing the pipe at great depth will make it difficult and costly to detect or fix any future sewage leaks into ORM aquifers. There is also a danger that the great pressures at this depth will allow groundwater to leak into the stormwater sewer. Groundwater leakage into the sewer is an ongoing loss from the natural aquifer system to the detriment of rural wells, Rouge streams and wetlands.

Better Alternatives can be Found

A significant portion of the existing York Durham sewer flows are from improper stormwater connections to sanitary sewers. To conserve and restore sewer capacity, the Region could disconnect stormwater flows from existing sanitary sewer pipes and accelerate water efficiency measures. These steps will provide additional sewer capacity and time to complete a proper environmental assessment and to find alternatives that will not drain the Oak Ridges Moraine and  suck wells, streams and wetlands dry. 

More Photos