Case Study: Ernest C. Drury School

For the E.C. Drury School in Milton, Ontario, Ontario Pipe Lining mechanically cleaned, lined, and restored a 150 ft-long corroded pipe system using Nu Flow technology. 

Project: E.C. Drury’s pipes were heavily backed up with calcite, causing water to flood onto the building’s new roof. The school’s roofing engineer believed Nu Flow’s Nu Drain product could help prevent further damage after the new roof was installed. Ontario Pipe Lining was brought on the project to mechanically remove the calcite build-up and restore the piping system before over 200 students returned from summer vacation.

Site: The E.C. Drury School for the Deaf in Milton, Ontario, built in 1980. 

System: 150 ft of 6 and 8-inch in diameter storm drain.

Problem: E.C. Drury had recently completed a $5 million dollar roof installation, however, a section of the new roof was flooded with water during a rainstorm. As this problem continued, the roofing contractor, the engineer, and the school tried to determine a solution. The engineer thought the problem could be related to the storm drain and contacted Ontario Pipe Lining for a condition assessment. 

Ontario Pipe Lining was awarded a small contract to line 75 ft of 6” underground storm drain. When Ontario Pipe Lining began assessing the downstream access, the condition of the pipe was reviewed and the problem was bigger than expected. The condition assessment confirmed the location and revealed that the main drain changed sized to 8”. An access pit was created outside on the grass and once the pipe had been opened OPL could fully inspect its condition.

The problem was much larger than simply relining a section of the deteriorated cast iron pipe inside the building. When the pipe expanded from 6” to 8”, the calcite (caused by the hard water) has restricted the flow of the pipe to 1” from the top of the pipe. Without a video inspection, it would’ve been challenging to assess the condition of the pipes and the degree to which they needed to be cleaned to ensure working order.

E.C Drury School

Solution: The video inspection revealed that the school’s hard water had created a heavy build-up of calcite within the pipe, restricting the flow from 6” and 8” to less than an inch over the 150 ft of the line. In order for the Nu Flow lining to attach itself onto the inside wall of the pipe, the calcite build-up needed to be thoroughly cleaned. Mechanical cleaning would also allow the pipe to open back up to its original diameter. As a result, the amount of lining required to renew the pipe doubled to 150 ft of 6” and 8” drain re-lining.

The pipe was mechanically cleaned by inserting a ½” cable with a variety of cutting heads designed to pulverize and re-open the pipe’s original diameter.

After the pipe had been cleaned, it was lined using one of Ontario Pipe Lining’s key manufacturer’s CIPP technology. With over 12 years of experience lining small diameter pipes, Ontario Pipe Lining can be trusted to install code-compliant CIPP drain re-lining technology. 

This CIPP technique allowed the pipe to be fully restored and lined, while avoiding large scale trenching and destruction of the surrounding area. Once the line had been strung, the pipe was repaired by pulling in the liner, verifying it was in place with a drain camera, and finally inflating a bladder up against the inside wall until the liner had cured. Once the pipe had cured, the bladder was removed, and final CCTV inspections were made to ensure the pipe was ready for immediate use.

Ontario Pipe Lining worked to get the job site cleaned before E.C. Drury’s students returned from summer vacation. Using the CIPP method, the newly-lined pipe is now stronger and more resilient to the water’s high calcite content, extending its lifetime to another 30 to 50 years. Routine video inspections will ensure the pipe is being properly cleaned and maintained over the years.