Dialogue: Traditional sewer systems tomorrow's pollution risks

The Government must do more than pay lip-service to the idea of publicly controlled water supply and sewerage, writes JOEL CAYFORD*.

The Government says it is opposed to the privatisation of water and that it wants urban communities to clean up wastewater.

Existing legislation, however, allows local councils to privatise water services in the teeth of local opposition. And sharply tightened environmental standards and high compliance costs are forcing communities to turn to private capital and transnational water giants.

In the absence of Government support, traditional sewerage solutions threaten to bankrupt communities and become tomorrow's pollution risks.

Last month, the Auditor-General concluded that it was difficult for the Thames Coromandel District Council to demonstrate that the sewerage reticulation option was indeed the best use of ratepayer funds.

This report was the latest episode in a long-running battle between most Cooks Beach lot owners and a council determined to fix septic tank problems by imposing a traditional reticulated sewerage scheme.

The council has decided to buy into a privately developed sewage treatment plant built to service an adjacent high-density subdivision.

Despite the fact that none of the lots outside the subdivision has yet been connected to the sewage treatment plant, all 600 lot owners are now being charged an annual sewerage fee of more than $400. The council estimates the capital cost to provide those properties with reticulated sewerage services will be $10.6 million.

The council made that decision despite advice from consultants that upgraded septic tank systems were suitable for the area, and in the face of a significantly cheaper quote for an alternative favoured by the residents and ratepayers association.

The council presumably assumes that the environment will be significantly improved after this investment on traditional systems, which reticulate all sewage solids and wastewater in big ceramic pipes for centralised treatment.

The Romans had the idea for that first and it was perfected by the British almost 200 years ago. But times have changed, as Sydney Water, faced with estimates of between $16,000 and $70,000 a lot for new centralised sewerage systems, discovered when it investigated developments in the United States and Europe.

It found that on-site wastewater services were used in 50 per cent of lots in Norway and 25 per cent of all lots in the US. On-site servicing is no longer seen as a temporary measure in the US, where 35 per cent of new city housing developments are now on-site serviced.

Beverley Hills is all on-site, and Barbra Streisand was among those who lobbied the council to keep it that way.

The US Environmental Protection Agency has advised the Government that decentralised systems, where properly managed, could protect water quality over the long term and do so at lower cost than conventional systems in many communities.

The most modern systems used in US cities combine sophisticated on-site primary treatment tanks, which retain and biodigest solids and need emptying every 10 years or so, and small-gauge leakproof pipes, which reticulate the liquid effluent only to either a centralised treatment plant or to small local treatment facilities.

While modern wastewater treatment plants in New Zealand are using cleaner technology, regular beach closures across Auckland testify that traditional sewerage reticulation pipe networks are dreadfully leaky and environmental disasters in themselves.

Even newly built, traditional sewerage pipe systems leak sewage out in dry weather, and in wet weather they leak rainwater in, reach capacity and cause sewage overflows. It is difficult to justify their construction and use in coastal environments if the goal is to protect and preserve water quality in the long term.

Mangawhai is the latest community to be on the receiving end of a council-imposed sewage treatment scheme. The local residents and ratepayers association has called for a septic tank bylaw and is anxious to consider alternatives which keep costs down.

But the Kaipara District Council, under pressure from the regional council to clean up the Mangawhai estuary and from developers keen to follow the Cooks Beach example and get intensive subdivision development under way, is pushing ahead with a planned $16 million sewerage scheme.

The district council has decided it cannot fund the project, and has put the whole project out to private tender. Five private organisations have been shortlisted. These include overseas companies.

It is interesting to note the strategies of water utility transnationals such as Vivendi and Lyonnaise des Eaux, which have service contracts and own and operate water and wastewater services around the world. They prefer to establish in countries with weak regulatory institutions. These companies have annual turnovers in excess of the gross domestic products of all but a few countries, and have huge power.

The limited extent to which the Papakura District Council has been able to exercise control on the relatively small United Water transnational through its franchise agreement is an example of this risk in New Zealand.

An Oamaru example suggests, however, that councils can handle these issues differently. The Waitaki District Council faced a $10 million bill to upgrade the local wastewater treatment plant. It held many public meetings over two years. At times the local Opera House was crammed as the council won support for a green wetland-based approach, paid for by optional upfront payments from each ratepayer. The council was able to fund the scheme without raising a loan and residents are proud of their treatment plant.

The North Shore City Council is preparing a plan for greenfield development at Long Bay. Traditional engineers have recommended traditional sewerage reticulation. Fortunately, most councillors have supported a much more thorough consideration of modern alternatives to water, wastewater and stormwater management.

Unhappily the question of how the North Shore council can require developers to pay for infrastructure needed to support their subdivisions remains unanswered.

The long-awaited funding powers review has been collapsed by the Government into the narrow changes of the Rating Powers Act.

It is all very well to talk about the powers of general competence and to oppose the privatisation of water. It is quite another to introduce legislation to provide national leadership that will make a positive difference to the environment and give local communities the control they seek over their futures.

* Joel Cayford is a North Shore City councillor.