Miss Adams' concerns about the site span nearly two decades.
In 1991, she laid crosses and tombstones at the site, protesting against the method being used to clean up arsenic, chromium and copper contamination.
The clean-up was based on a plan prepared by consultants for the treatment plant's former operator, Placemakers.
It was approved by the Ministry for the Environment, and in consultation with the Department of Conservation, Otago Area Health Board, Otago Regional Council and National Toxicology Centre.
But Miss Adams was not happy at the plan to bury the contaminated material in a pit at the foreshore.
In November, she sent soil samples to a laboratory in Hamilton for testing, concerned about what she believes are unacceptable levels of arsenic.
She believed the area had not been cleared of toxic waste, it was still a contaminated site and it needed to be investigated and dealt with.
The problem was being exacerbated by coastal erosion, she said.
In a letter to Miss Adams last week, Otago Regional Council contaminated sites officer Paul Kennedy said the Waitaki District Council was planning a detailed site investigation, following Ministry for the Environment guidelines for contaminated land management.
An ORC application to the contaminated sites remediation fund, administered by the ministry, to assist with the investigation, was submitted in October.
A decision was pending.
Miss Adams was also concerned the bore holes had not been maintained and that sampling of the sites ceased in 1998.
She intended sending the test results to the ORC.
