The sludge lagoons at the Aerotech Business Park, serving the Halifax Regional Municipality in Nova Scotia, were constructed in the late 1980's as an interim facility until the regional waste management strategy could be finalized and implemented. With a projected 7 year life, the lagoons became filled in 1996 (after 8 years of use) and the lagoon effluent was having a detrimental impact on downstream treatment processes. ABL was retained to investigate options for removal and disposal of the accumulated sludge and to upgrade the receiving station.

Sludge quality was investigated and models were developed for land application. The time of year, however, dictated that sludge material be removed and hauled to a remote composting facility. ABL prepared tender specifications and provided contract administration duties for the lagoon cleaning. ABL also designed an upgrade to the receiving station to reduce operator exposure to pathogenic material and to reduce the plastic debris in the lagoon, so that future cleanouts would proceed more smoothly. ABL completed a second cleaning of the sludge lagoon in 1999, again extending the useful life of this facility until the regional plan takes effect.