Scientist pushes for treated effluent to be part of water resources
BY KIMONE THOMPSON Associate editor -- features email@example.com
REUSING wastewater might not be able to alleviate the current crisis of water shortage and raging bush fires brought on by the prolonged dry spell being experienced across the island, but biochemist and bioprocess engineer Denise Forrest believes it ought to form part of government's water strategy for future planning.
Wastewater is defined as any water contaminated by human use. It is generally put into two categories: greywater -- that generated from wash tubs, washing machines, kitchen sinks, face basins, showers and baths and which can be recycled on-site for uses such as toilet flushing and landscape irrigation -- and darkwater or sewage -- that which contains urine and or faeces.
Experts contend that properly treated, greywater can be recycled primarily for agricultural and industrial purposes. They say that apart from supplementing the amount of water available and thereby conserving the natural resources, it can eliminate the need for fertilisers as it has a high concentration of nitrogen, phosphorus, and potassium, which are normally required for agricultural crop production.
According to the United Nations Food and Agriculture Office, micronutrients and organic matter found in greywater also provide additional benefits to crops.
In Jamaica's context, Forrest says using treated greywater on a national scale would require significant infrastructure, especially considering the location of wastewater treatment plants in relation to farms and irrigation canals. As such, she said, it could not be realised in the short term but that should not deter policymakers from taking a serious look at the possibilities.
"I have to tell you that wastewater is not a magic wand, and it won't be possible tomorrow but it is very possible in the medium term, say in the next three to five years... We have to incorporate it in our water requirement strategies -- domestic, agricultural, industrial, and so on. If you look at the demand, the agriculture and industrial sectors have the highest demand for water and those are supposed to be growth engines for this country. If they don't have water there we can forget it in terms of future development," she told the Jamaica Observer yesterday.
"When we look at the wastewater treatment facilities in the country, government did invest significant amounts of money in Negril, in MoBay -- the ponds, in Ocho Rios -- the mechanical plant, and in Kingston -- the Soapberry plant. These facilities are producing treated wastewater and this water could be used for agricultural use once (the bacteria) are at acceptable levels... because remember the country's whole economic situation is (heavily dependent on agriculture). We'd be surprised at the contributuion of agriculture to GDP and it's not only the farming community, but the community that survives off farming activities, the transport sector, the higglers, etc. So it's a significant community that's going to be affected if farmers are unable to plant, if plants are unable to grow and the commerce that results from that does not happen," she continued.
Forrest is managing director of Forrest and Associates, an environment and project management consultancy. She is the former project coordinator for the Caribean Regional Fund for Wastewater Management (CReW), a four-year project designed to provide sustainable financing for the wastewater sector, support policy and legislative reforms, and foster regional dialogue and knowledge exchange among key stakeholders in the Wider Caribbean Region.
CReW is financed by the Global Environmental Facility and is being implemented by Inter-American Development Bank and the United Nations Environment Programme through its Caribbean Regional Coordination Unit based in Kingston.
Of the current dry spell, Forrest said the wastewater option is even more valid given the climatological projections that have temperatures climbing and the weather becoming even drier.
"If truth be told, if the country looks at the issues in relation to climate change, if the country looks at the issues in relation to droughts, if the country looks at the projections for an even drier 20-year spell in the next period, then we now need to begin to put wastewater into the scheme of things for water use, fit for purpose," she said.
"It's one of the adaptive measures for climate change that we must undertake as a country," she continued. "It is important to the life of the country, to the economic life of the country, the future of the country. Many things would be derailed if we don't get it right."
The biochemist added: "I think what this particular situation tells us, and I think it's a significant wake-up call, I hope we don't take it as a nine-day wonder that will (wash away) when rain comes. I hope in our planning cycle we begin to examine this because wastewater is a very, very significant water resource. Even at the household level, people perhaps need to begin to think about how we plumb our houses for the reuse of greywater -- water from our washing and so on that could be diverted to our gardens and make some contribution to the overall water balance."