No wasted effort

Updated on: Tuesday, October 04, 2011

A group of students from University of Alberta, Canada, were assigned the task to reclaim the former site of a waste treatment plant. Tirna Ray reports

As part of a capstone course for land reclamation students, a group of students from University of Alberta, Canada , has come up with a classic country way to reclaim a used-up sewage plant in Lac La Biche. As M Anne Naeth, director, Land Reclamation International Graduate School (LRIGS), University of Alberta, points out, "Lac La Biche Lake is in the boreal forest of Alberta, which includes islands and over 200 bird species."

The lake drains an area of 4,040 km. A large portion of the land near the lake is agricultural with pasture and hay production. The town of Lac La Biche began discharging sewage into the lake in 1951; a waste water treatment plant later operated near Field Lake. Since the construction of the plant, Field Lake has received sewage effluent from the town of Lac La Biche; Eutrophication of Lac La Biche Lake had become a hindrance on the town, and the stagnation of Field Lake had become a severe environmental issue.

The students were assigned the task to reclaim the former site of the waste treatment plant, the lagoons and the surrounding area. "For purposes of the study we created a scenario of a leak of 875 min the clay liner due to improper water content and compaction in the north-end of the west lagoon, which allowed sewage contaminants to leach into the surrounding soil. Contaminants found in the subsoil below the clay liner were salts, cadmium, chromium, copper, zinc, mercury and lead, affecting 4,815 mof soil," Naeth adds.

The students proposed a reclamation plan to rectify the damage done to Lac La Biche Lake and the surrounding areas including steps to decommission the plant and remove infrastructure including pump the lagoons dry, reducing nutrient levels in the soil, etc.

CHALLENGES

Students had to face numerous challenges. Not only did they have to cover decommissioning of the infrastructure, soil reclamation, contaminant remediation and revegetation to desirable plant species, but also, they had to take into consideration all regulatory components of the province of Alberta and of Canada. "In class we discussed general approaches to each of soil reclamation, contaminant remediation and revegetation and then they would apply this to their project," Naeth says.

Naeth feels the experience helped students to deal with real-life challenges and learn how to apply what they learned in their degree programme. As to the future, the lake would no longer be contaminated and the land would be useable as agricultural lands.

Times of India

No wasted effort

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