Wasting our water

Wasting our water: lost opportunities for improved water quality.

The recent incident at Osberstown, resulting in the pollution of 20 miles of the Liffey by untreated outflow from the wastewater treatment plant there, highlights fundamental problems with the provision of wastewater treatment services in Ireland.

Water quality management focuses on the control of eutrophication by controlling nitrate and phosphate discharges. Eutrophication is enrichment of water manifesting itself as algal blooms and plant growth. This leads to depleted oxygen levels that can cause fish kills.

A report prepared as part of the Water Framework Directive implementation process estimates that agricultural pollution is the single biggest source of nitrate discharge to fresh surface waters in River Basin Districts (75% of national total load by sector). Consequently, tackling the agricultural Nitrate issue will affect significant improvements our water quality. However, doing so remains a labourous and politically fraught undertaking that will not be easily resolved in the short term.

Although contributing much less, wastewater treatment plants, unsewered industries and unsewered populations are estimated to be the second largest source of Nitrates in every River Basin District. While in four River Basin Districts wastewater is estimated to be single largest contributor to phosphate levels in fresh surface waters.

Control of point source pollution from wastewater treatment plants, unswered industries and unswewered populations, should be straightforward. The location of outflow can be easily determined, and there are defined treatment regimes and sampling programmes. Unfortunately, many industries remain unsewered while a significant portion of the population are dependant on septic tanks. This article is going to focus on the inadequacies in wastewater treatment facilities for the sewered population (Wastewater Treatment Plants) – which appear to be both systemic and endemic.

The level of treatment that wastewater receives depends on the size of the population, expressed as a population equivalent (or p.e); the type water that receives the waste, and the risk that the receiving water body has of becoming eutrophic. This risk defines a water body as either sensitive to eutrophication or non-sensitive to eutrophication.

In Ireland there are 7 lakes, 18 rivers and 12 estuarine/marine waters classified as sensitive. Crucially, such designations do not necessarily refer to the entire water body. For example sections of a river can be designated and distinction is made between inner and outer or upper and lower estuary areas.

In 2004 the European Commission noted that Cork Harbour, the River Boyne, Lady’s Island and Garavogue/Sligo suffered in their opinion from eutrophication. Since then parts of Cork Harbour have been defined as sensitive. Ireland has yet to designate the other water bodies as sensitive, our failure to do so is one reason for ongoing infringment proceedings in the European Court of Justice.

Those areas sensitive to eutrophication required that secondary (or biological) and tertiary (nitrogen and phosphorous nutrient removal) treatment facilities were implemented by the end of 1998 for all communities larger than 10,000 p.e. The current level of treatment for some of those communities is listed below.

Secondary treatment was required by the end of 2000 for all communities with a p.e. of 15, 000 or more. The current level of treatment for some of those communities is listed below.

Finally, the appropriate treatment facilities were to be extended to all communities of 2,000 to 15,000 p.e. by the end of 2005. Given the number of these communities that had inadequate facilities in 2003 (17 such communities had no treatment facilities at all) it is unlikely that this deadline has been met.

Where treatment facilities are operational, there are problems with the ability of existing plants to process volumes of wastewater.

An EPA report on compliance with the phosphorous regulations published this year recognises that municipal pollution problems are significant on a national basis “due to, for example, overloading of wastewater treatment plants, poor performance of plants and stormwater overflows.”

Osberstown has been a source of European Commission concern for several years. In 2004 the European Commission expressed concern about it’s capacity: “Despite its existing nutrient removal facilities, the agglomeration Osberstown was not considered to conform with the Directive [Urban Waste Water Treatment Directive], because its treatment capacity seemed too small for a sufficient waste water treatment… According to the Commission’s opinion the treatment plant of Osberstown has to be subject to a capacity upgrading.”

Information on the Osbertown website indicates that a capacity upgrade to 80,000 p.e was complete in 2001. It is not clear what level of treatment the plant operates. A further upgrade to 130,000 p.e. is now required. This isn’t expected to be finished until 2008. Enquiries to the Manager at Osbertown failed to shed light on the current treatment situation at the plant.

Problems with treatment facilities appear to extend beyond capacity and operational issues to the sampling procedures from which water quality is determined. Again an EPA report from 2004 states that “grab sampling, the principal method used by Local Authorities, is not specified in EU Regulations and is not sufficient to establish compliance.” Such a statement implies that Local Authorities were using a sub-standard technique to determine water quality parameters.

An EPA report due out later this year should shed light on whether this continues to the be the case.

With this in mind, it is little wonder that pollution incidents from wastewater treatment plants are cause for serious concern, and wonder too that our waters remain in as good a biological condition as they appear to.

Sewage and water treatment runoff accounted 46% of ‘serious’, 74% of moderate and 73% of slight pollution incidents in the period 2001 – 2003. The EPA could not provide figures for the period 2004 – 2005.

A Heritage Council survey of public attitudes towards water found that pollution related to sewage treatment was one of the three largest issues of concern amongst those who took part.

Ireland has an auspicious record of non-compliance with EU water quality related legislation. The Dangerous Substance Discharges Directive, Nitrates Directives, Shellfish Directives and Urban Wastewater Directives have variously been the source of written warnings and/or court proceedings at a European level. Issues of concern include a failure to adhere to obligations, a failure to adopt pollution reduction measures, lack of regulation of emissions and a failure to designate areas sensitive to pollution. In several cases Ireland has still to fully comply.

Water Services Investment Propramme (WSIP) is the driving force behind water infrastructure. At the end of 2004, completed wastewater projects since 2000 had generated an additional capacity of some 3 million p.e. In the same period, the increase in water treatment capacity was 578,000 p.e.

Continued investment in this programme, construction and upgrade of wastewater treatment plants and collection systems, including storm water overflows, needs to be prioritised. The EPA advises that phosphorous removal facilities be considered for all plants discharging into fresh waters. Appropriate plant monitoring and management is required to observe that standards are met and maintained. This will become necessary one the EU begin to assess how well plants are working.

Loughs Leane, Derg, Oughter, Ree, Muckno, Monalty, Ennell

Rivers Boyne, Camlin, Castlebar, Liffey, Nenagh, Tullamore, Blackwater (Monaghan), Brosna, Cavan, Proules, Barrow, Triogue, Nore, Hind, Suir, Little Brosna, Blackwater ( Munster), Owennacurra

Broadmeadow Estuary (Inner), Liffey Estuary, Slaney Estuary, Barrow Estuary, Suir Estuary (Upper), Bandon Estuary, Lee Estuary/Lough Mahon (Cork), Cashen / Feale Estuary, Killybegs, Castletown Estuary, Blackwater Estuary, Lee Estuary Upper (Tralee)