Sir, - You report (The Irish Times, November 12th) that the citizens of Galway are worried that a "pay by weight" scheme for waste charges will increase fly tipping. No doubt it will - but they should worry more about the less visible means of improper disposal.
Burning household wastes, for example, will generate a range of atmospheric pollutants, including dioxins, and leave heavy metals behind in the ashes, whether on the living-room fire or on a bonfire. Regular spreading of these ashes on gardens may gradually poison the soil and any vegetables grown there. Smoke is visible, of course, but it is hard to check what is being burned.
Buried wastes will generate methane, which is flammable, potentially explosive and a potent greenhouse gas. Rainwater will carry a range of toxins into the subsoil and potentially into groundwater supplies.
Wastes awaiting burning or burial will attract crows, rats, flies and other pests, which may scatter the waste as well as spreading disease. Large accumulations may become fire hazards or develop into mini-landfills.
Waste-disposal units beneath kitchen sinks squander water and add significantly to the polluting power of sewage. Overloaded septic tanks or sewage works may then pollute our rivers.
Such practices will often go undetected and will generally endanger the community as much as they do the polluter. This is why cities have provided refuse collection as a "free" public service since the days of Ancient Rome.
Weight-based charging is intended to reduce our waste output by encouraging "virtuous" alternatives, such as more selective shopping and home composting. However, if these are less attractive to many householders, the net effect of waste charges (especially if weight-based) might be more pollution, not less. Some of it will be widely dispersed. Some will be confined to the polluter's land and the risk to subsequent occupants and their children may not emerge until years later.
Weight-based charging will come, nevertheless. It is the only known way of encouraging householders to take personal responsibility for the amount of waste they generate and to apply knock-on pressure on retailers. However, the prerequisites are not yet in place in Ireland. These include a strong sense of self-responsibility and respect for the law among the vast majority of the population, along with an effective system of detection and law enforcement, actively supported by the majority.
How will we know when the time is ripe for weight-based charging? Would a good indicator be litter levels to compare with those in Sweden or Austria? - Yours, etc.,
Dr Duncan J Martin, Senior Lecturer in Chemical Engineering, University of Limerick.