Auckland City Council admits it should have informed residents of the Harbor Bridge contamination

By RNZ’s Phil Pennington

Auckland City Council has admitted it was at fault for failing to inform North Shore residents about the pollution arising in part from the maintenance of the Auckland Harbor Bridge.

RNZ disclosures of heavy metal and hydrocarbon contamination discovered by the Transportation Agency a decade ago have alarmed Stokes Point / Te Onewa residents.

There wasn’t enough certainty to put a pollution label on household LIM (Land Information Memorandum) reports now, the council said.

“The threshold for this is whether it is ‘likely'” that there was a risk to human health, council Director of Regulatory Services Craig Hobbs said in an internal email to the mayor, council executive director and two local councilors. delivered to RNZ.

“Because there was no risk, there was no need to notify anyone or record anything in the property files,” Hobbs said.

However, the council should have told the locals what had been found in two rounds of testing in 2010/11, he said.

“In my opinion, the biggest flaw … is that neither the city council nor the NZTA spoke with the neighbors and shared the test results at that time.

“While no human health problems were identified, the fact that we remain silent now has opened us up to criticism as we react after the fact.”

The NZTA documents show that their own health risk assessment found that most of the properties were likely fine, but they recommended further testing. This did not happen.

The households were not informed and the residential tests were never carried out.

The agency delivered its 2010 findings to the council and regional public health officials, who urged the NZTA to inform residents, analyze the soil on their properties, and investigate the broader impacts on the marine environment of high levels of zinc. , lead and copper.

No ‘unacceptable’ risk

The council did a health risk assessment in 2011 based on sampling in the public preserve at Stokes Point; this followed a risk assessment by NZTA.

“The summary on page 13 states that ‘in general, the levels of contaminants do not represent an unacceptable level for human health,'” Hobbs said in the internal email.

“Based on the information we have, specifically the conclusion of the risk assessments, there is not enough certainty for the council to place some kind of ‘label’ on adjacent properties for contamination.

“The threshold for this is whether it is ‘likely’.”

In previous years, LIM’s labeling with regard to contamination in other parts of Auckland has been highly controversial.

Even after the 2011 risk assessment, the council continued to speak with regional health officials until 2012 about the contamination and undertook its own remediation of a small area of ​​the reserve.

This was next to a route where the carcinogenic hydrocarbon BAP was found; the samples rated this up to 30 times the allowable levels.

“This involved covering the area with a geotextile mat and 100mm of mulch,” Hobbs said.

What was considered a safe level of BAP had risen sharply since 2011, he added.

NZTA manager lobbied for residents to be informed

The National Environmental Manager for the Transportation Agency at the time, Carl Reller, told RNZ that local residents could have done simple remediation work on their grounds as well, had they been told – something he urged to be done during two years.

Hobbs in his email downplayed the bridge as a source of contamination, saying that lead paint in homes and leaded gasoline could be a source.

However, lead levels increased at Stokes Point between the only two sample lots, in 2001 and 2010/11, long after the gasoline and lead paint were removed.

There are likely sources of contamination in the reserve that are not found on private property, particularly old fill material and an old coal tar trail, Hobbs said.

“Bridge-related pollution associated with maintenance and traffic is described as less important sources,” he said.

“Lead measurements in the reservoir may not be the result of bridge maintenance activity.”

This contradicts a 2012 NZTA document that said the lead and zinc distribution matched the bridge alignment, “suggesting that the bridge or highway are likely sources of lead and zinc,” although BAP’s findings were more scattered. and “no does not map to AHB as the exclusive source.”

Hobbs said the council documents showed that NZTA planned to conduct tests on residential properties adjacent to the bridge.

In July 2012, the agency “informed the council that letters had been sent requesting permission to test residential properties.”

But this did not happen.

NZTA documents show that a mailing was canceled in July 2012. “It appears to have not gone through,” Hobbs said.

The council had told the agency in February 2011 that if it did tests on the houses, “owners should be aware of the implications, meaning that the council would record any confirmed contamination in the property / LIM file for these properties “.

In 2011, regional public health officials also raised the possibility that prospective home buyers may need to be counseled on LIMs.

Health officials did not follow up beyond 2012 to see if the NZTA followed their recommendations, and it did not, according to Auckland Regional Public Health’s statement to RNZ.

The Transportation Agency wrote to residents this month after RNZ reported the contamination, saying current controls on the bridge were effective.

Its latest annual report summarizing environmental monitoring data showed that it was in compliance with the council’s Environmental Management Plan, the agency said.

RNZ has requested the publication of the annual reports.

An internal NZTA document from 2011 said the bridge’s maintenance operation had breached half of the 15 consent conditions since 2001.

Neither the agency nor the council have responded to RNZ’s questions about those violations.

The agency in its October 2 letter said that “a specific report is required if an event occurs that results or has the potential to result in a violation of the consent conditions or adverse effects on the environment, such as a significant discharge in air or water. “.

Sampling shows that zinc and copper levels have increased in port water in the vicinity of the bridge, according to official reports.

– RNZ