Cement manufacturer Holcim New Zealand is to start assessing sites near Oamaru as it looks at the possibility of building a new plant. The company wants to find a way to boost output as production from its 48-year-old manufacturing operation at Cape Foulwind, Westport is failing to meet demand.

Holcim today said it would be carrying out preliminary fieldwork at three sites near Oamaru in the next three to four months, and would start on a range of assessments into such things as engineering feasibility, raw materials and ecology.

One of the sites, at Weston, was bought 25 years ago as a potential site for a new cement plant which had not gone ahead at the time. While the site had the appropriate zoning, new consents would be needed if a plant were to be built there, the company said.

It also needed to evaluate company-owned mineral reserve sites at nearby Windsor and Ngapara for possible quarrying.

Another option being looked at was the upgrading of the Westport plant. Exploratory drilling of potential mineral reserves in the area had been carried out in the past year, and an engineering appraisal of the plant and modern upgrade options were under way.