Hamilton City Council can continue discharging leachate and landfill gas from the closed Willoughby Street landfill on the condition it puts in place a range of measures to protect people, property and the environment.
The 5.4 ha site, bounded by the Willoughby Street Cemetery, the Waitawhiriwhiri Stream and Ulster Street, was used as a landfill from the 1920s until its closure in 1973. The area is now the site of Beetham Park and a golf driving range. There are also a number of community facilities, residential houses and motels surrounding the site on Ulster and Richmond streets, some of which have been built over areas once used for waste disposal.
Landfill gas, made up of mainly methane and carbon dioxide, is produced from organic waste disposed of in landfill. Over time the organic waste is broken down and landfill gas is produced. This gas builds up and is slowly released into the atmosphere presenting a number of health, safety and environmental concerns. These range from risk of fire and explosion through to concerns about global warming, air pollution and odour nuisance.
The decision detailing the required measures follows a resource consent hearing in August. The conditions imposed by Environment Waikato’s three-member hearing committee are based on internationally accepted best practice for managing risk associated with landfill gas emissions.
As a condition of its consent, the city council must install a gas barrier and venting system at the boundary of Beetham Park to prevent gas escaping from the main body of the old landfill into neighbouring properties. The venting system must also be designed to avoid nuisance odours associated with landfill gas.
Regarding the application to discharge leachate into the ground from where it could enter the Waitawhiriwhiri Stream, the committee found the effects of the leachate discharge on the stream were likely to be minor, but that the ongoing discharge adversely affected the cultural and spiritual values of Maori.
To address concerns raised by Te Kotuku Whenua, the environmental agency of Ngati Wairere, the committee ruled the city council should bring forward works aimed at minimising any direct discharge of leachate into the stream to 2010.
Te Kotuku Whenua submitted that the works should be completed by January 2009 while the city council had proposed these works would be undertaken in the 2013/14 financial year as part of the development of a walkway through the gully.
Provided the conditions are met, Environment Waikato has granted Hamilton City Council resource consents to discharge leachate and landfill gas from the old dump for the next 35 years.
The hearing committee comprised Environment Waikato councillors Jim Howland, Laurie Burdett and Andra Neeley.