Taro ammonia led to need for homes' cellar capping

Community Aug 25, 2016 by Richard Leitner Stoney Creek News

Potential impacts from the closed Taro west quarry industrial dump – not the active one to the east – prompted the city to require a clay cap underneath the basement of homes in the Lush at Victory survey north of Green Mountain Road.

A 2010 consultant’s report prepared for developer Empire Communities (Stoney Creek) Inc. recommended the layer of “clayey silt soil” between the highest groundwater elevation and basement foundations to prevent ammonia vapour from getting into homes.

MTE Consultants Inc. noted ammonia was one of 11 elements with elevated levels in leachate from the west dump, controlled by pumping wells because, unlike the new Taro dump, it has no liner system.

While the leachate is sent into the sewer under an agreement with the city, monitoring showed some either was or may have been, depending on the groundwater level, flowing north of Green Mountain Road, states the report, which wasn't made public at the time.

“Ammonia is soluble in water, but will volatize readily, and could, at high enough concentrations pose a problem to indoor air quality of residents in the proposed development,” MTE states.

“In the case of vapour concentrations to outdoor air, the pathway is considered minimal compared to the confined conditions of a residence; therefore, only the assessment of ammonia from groundwater to a residential building was completed.”

The ammonia concerns led MTE to recommend – and the city to require – the clay protection beneath homes within 500 metres of both dumps’ boundaries.

The area’s zoning bylaw also put a no-build holding zone on the third phase of the survey – affecting 90 maisonette townhomes – because they fell within 160 metres of the active dump’s waste boundary.

But that was before former owner Newalta Corp. got provincial permission in 2013 to shrink the dump’s footprint, moving away from Green Mountain Road, in return for being able pile waste 4.5 metres higher.

The reduced footprint took the maisonette homes out of the holding zone.

New owner Terrapure Environmental Inc. is proposing to return the active east quarry dump to its original footprint, raise its height another three to four metres and boost its waste capacity by about seven million tonnes.

In an emailed response to questions the Stoney Creek News submitted to city planners, the department’s spokesperson, Ann Lamanes, said the Terrapure bid doesn’t affect the number of homes requiring the clay layer because original boundaries applied.

Asked whether a return the dump to its original footprint would require the city to revisit the holding zone for the maisonette homes, she stated that Empire has met the condition, but doesn’t want to sell the units until it’s confident it can meet closing dates.

“These lands have all of the required planning approvals and Empire is proceeding to clear the conditions of draft plan approval, including, but not limited to, municipal engineering approvals,” Lamanes stated.

“There is no connection between the timing of the review, the city’s requirements and the proposed changes at the Terrapure facility.”

Terrapure has said it is confident it will be able to demonstrate that the expansion will have no off-site impacts.

Taro ammonia led to need for homes' cellar capping

Old west dump leaking toward new housing survey to north: report

Community Aug 25, 2016 by Richard Leitner Stoney Creek News

Potential impacts from the closed Taro west quarry industrial dump – not the active one to the east – prompted the city to require a clay cap underneath the basement of homes in the Lush at Victory survey north of Green Mountain Road.

A 2010 consultant’s report prepared for developer Empire Communities (Stoney Creek) Inc. recommended the layer of “clayey silt soil” between the highest groundwater elevation and basement foundations to prevent ammonia vapour from getting into homes.

MTE Consultants Inc. noted ammonia was one of 11 elements with elevated levels in leachate from the west dump, controlled by pumping wells because, unlike the new Taro dump, it has no liner system.

While the leachate is sent into the sewer under an agreement with the city, monitoring showed some either was or may have been, depending on the groundwater level, flowing north of Green Mountain Road, states the report, which wasn't made public at the time.

“Ammonia is soluble in water, but will volatize readily, and could, at high enough concentrations pose a problem to indoor air quality of residents in the proposed development.”

“Ammonia is soluble in water, but will volatize readily, and could, at high enough concentrations pose a problem to indoor air quality of residents in the proposed development,” MTE states.

“In the case of vapour concentrations to outdoor air, the pathway is considered minimal compared to the confined conditions of a residence; therefore, only the assessment of ammonia from groundwater to a residential building was completed.”

The ammonia concerns led MTE to recommend – and the city to require – the clay protection beneath homes within 500 metres of both dumps’ boundaries.

The area’s zoning bylaw also put a no-build holding zone on the third phase of the survey – affecting 90 maisonette townhomes – because they fell within 160 metres of the active dump’s waste boundary.

But that was before former owner Newalta Corp. got provincial permission in 2013 to shrink the dump’s footprint, moving away from Green Mountain Road, in return for being able pile waste 4.5 metres higher.

The reduced footprint took the maisonette homes out of the holding zone.

New owner Terrapure Environmental Inc. is proposing to return the active east quarry dump to its original footprint, raise its height another three to four metres and boost its waste capacity by about seven million tonnes.

In an emailed response to questions the Stoney Creek News submitted to city planners, the department’s spokesperson, Ann Lamanes, said the Terrapure bid doesn’t affect the number of homes requiring the clay layer because original boundaries applied.

Asked whether a return the dump to its original footprint would require the city to revisit the holding zone for the maisonette homes, she stated that Empire has met the condition, but doesn’t want to sell the units until it’s confident it can meet closing dates.

“These lands have all of the required planning approvals and Empire is proceeding to clear the conditions of draft plan approval, including, but not limited to, municipal engineering approvals,” Lamanes stated.

“There is no connection between the timing of the review, the city’s requirements and the proposed changes at the Terrapure facility.”

Terrapure has said it is confident it will be able to demonstrate that the expansion will have no off-site impacts.

Taro ammonia led to need for homes' cellar capping

Old west dump leaking toward new housing survey to north: report

Community Aug 25, 2016 by Richard Leitner Stoney Creek News

Potential impacts from the closed Taro west quarry industrial dump – not the active one to the east – prompted the city to require a clay cap underneath the basement of homes in the Lush at Victory survey north of Green Mountain Road.

A 2010 consultant’s report prepared for developer Empire Communities (Stoney Creek) Inc. recommended the layer of “clayey silt soil” between the highest groundwater elevation and basement foundations to prevent ammonia vapour from getting into homes.

MTE Consultants Inc. noted ammonia was one of 11 elements with elevated levels in leachate from the west dump, controlled by pumping wells because, unlike the new Taro dump, it has no liner system.

While the leachate is sent into the sewer under an agreement with the city, monitoring showed some either was or may have been, depending on the groundwater level, flowing north of Green Mountain Road, states the report, which wasn't made public at the time.

“Ammonia is soluble in water, but will volatize readily, and could, at high enough concentrations pose a problem to indoor air quality of residents in the proposed development.”

“Ammonia is soluble in water, but will volatize readily, and could, at high enough concentrations pose a problem to indoor air quality of residents in the proposed development,” MTE states.

“In the case of vapour concentrations to outdoor air, the pathway is considered minimal compared to the confined conditions of a residence; therefore, only the assessment of ammonia from groundwater to a residential building was completed.”

The ammonia concerns led MTE to recommend – and the city to require – the clay protection beneath homes within 500 metres of both dumps’ boundaries.

The area’s zoning bylaw also put a no-build holding zone on the third phase of the survey – affecting 90 maisonette townhomes – because they fell within 160 metres of the active dump’s waste boundary.

But that was before former owner Newalta Corp. got provincial permission in 2013 to shrink the dump’s footprint, moving away from Green Mountain Road, in return for being able pile waste 4.5 metres higher.

The reduced footprint took the maisonette homes out of the holding zone.

New owner Terrapure Environmental Inc. is proposing to return the active east quarry dump to its original footprint, raise its height another three to four metres and boost its waste capacity by about seven million tonnes.

In an emailed response to questions the Stoney Creek News submitted to city planners, the department’s spokesperson, Ann Lamanes, said the Terrapure bid doesn’t affect the number of homes requiring the clay layer because original boundaries applied.

Asked whether a return the dump to its original footprint would require the city to revisit the holding zone for the maisonette homes, she stated that Empire has met the condition, but doesn’t want to sell the units until it’s confident it can meet closing dates.

“These lands have all of the required planning approvals and Empire is proceeding to clear the conditions of draft plan approval, including, but not limited to, municipal engineering approvals,” Lamanes stated.

“There is no connection between the timing of the review, the city’s requirements and the proposed changes at the Terrapure facility.”

Terrapure has said it is confident it will be able to demonstrate that the expansion will have no off-site impacts.