By R. Laird Smith, P.Eng., Senior VP, Engineering Services, Azurix Corp.
Following their Best Practices Guidelines to better manage the use of activated carbon for taste and odour removal from drinking water, the Regional Municipality of Niagara Public Works entered into a Public/Private Partnership (P3) with Horseshoe Carbons, Inc.
The process identified eight interested parties, of which five were selected to submit detailed proposals for a five-year activated carbon management program. Operations Manager Sal Iannello explained the Region's interest in the program: "We have used both powder and granular activated carbon and monitored taste and odour reduction since 1993. We would like to replace the carbon annually but the costs are too high. We felt this approach would allow us to obtain a comprehensive service at the lowest possible cost."
The Region's experience with activated carbon led them to the conclusion that a longer contract would allow for more innovative proposals, translating into savings for the Region. Granular carbon with a three-year life cycle was identified as the best practical alternative.
Horseshoe Carbons, a joint venture between Azurix Corporation and PICA (Produits Industriel et Charbons Actif) was awarded the contract. In fact, the company was indirectly formed as a result of the Region's efforts to find innovative solutions to carbon management. In early 1997, the Region held a two-day session where they entertained carbon management presentations from carbon suppliers and engineering/service providers. "I presented carbon reactivation at that time on behalf of PICA but I also learned about the other presenters. We saw some definite synergies with Azurix and it was not long before we had teamed-up on the project," said Robert MacLean of Horseshoe Carbons.
In-house reactivation, as practised in Cincinnati, Ohio, Manchester, New Hampshire and Buffalo Pound, Saskatchewan, has been used by municipalities with large carbon volumes and relatively short service lives. For Niagara, their turnover could not justify the construction of a dedicated facility so a P3 was the next best alternative. The cost of building and financing the facility was left to Horseshoe Carbons. The Region will benefit from a fixed price over the 5-year term and will pay Horseshoe Carbons in 60 monthly installments. Horseshoe is scheduled to commission Canada's first potable water custom reactivation facility for granular activated carbons in Hamilton by January 2000.
This type of long-term partnership for taste and odour control using virgin and reactivated granular carbon in combination will no doubt spawn interest among other municipalities. In Niagara, the Region was able to reduce costs by over 25% when compared to their 1998 figures.
According to MacLean, the effectiveness of reactivated carbon for taste and odour control, when compared to virgin carbon, should be as good as 98%: "In Ontario and most of Quebec, because the level of inorganic loading on spent carbons is typically quite low, reactivation is very effective in recovering the carbon's original capacity."