2016 Havelock North Drinking Water Contamination James Palmer, Incoming Chief Executive

Havelock North Drinking Water Contamination Summary Before the outbreak: what we failed to do Following the outbreak: what our investigations showed about the aquifer Looking forward: what we are doing and planning to do

Before the 2016 outbreak: what we failed to do In 2008 relied on information submitted by applicant (HDC) for Brookvale resource consents without independent review. 2008 focus on protecting the environment, not on drinking water safety. Relied on consent holder to provide reports on condition of bores without HBRC undertaking own physical inspection and enforcing conditions. Needed to more robustly consider the National Environment Standard for Drinking Water Sources (NES) in assessing resource consents. Had yet to review permitted land use effects on Brookvale supply. Failed to adequately convey significance of adverse State of the Environment monitoring results at nearby shallow bore. Focused on protecting water sources, including Heretaunga aquifers, at scale and not for very localised effects immediately surrounding bores.

Our investigations: what we did Initiated immediately following outbreak. Developed with advice from Institute of Environmental Science and Research (ESR) scientists Identify potential environmental sources of contaminated faeces Identify potential pathways for transmission to water supply bores Use ‘screening’ approach to test environment: Test for Escherichia coli (E. coli) – an indicator of faecal contamination If E. coli present, then test for presence of Campylobacter If Campylobacter present, then identify type (avian/human/ruminant)

Unlikely to originate from Tukituki River E. coli in Tukituki River typical of monthly values (suitable for swimming) Some groundwater sites have total coliforms – likely non-faecal origin North Groundwater flow No coliforms (bores) Key Low E. coli in Tukituki R. Low total coliforms (bores) High total coliforms (bores)

E. coli not in groundwater near water supply bores North No coliforms (bores) Key Low E. coli in Tukituki R. Low total coliforms (bores) High total coliforms (bores)

High levels of E. coli in local surface water Drainage network on Te Mata Mushrooms site has high E. coli Stream east of HDC borefield also has high E. coli North

What our investigations showed No evidence of wider contamination of groundwater. DNA link to sheep faeces in nearby paddocks that likely flowed to Mangateretere Stream and drains where Brookvale bores 1 and 2 are situated. Dye testing conducted jointly with HDC demonstrated a suprisingly rapid pathway from Mangateretere Stream to Brookvale 1 bore. Combination of clear tests in bores surrounding Brookvale bores and dye testing demonstrated that the contamination was most likely caused by Brookvale 1 pumping drawing surface water into the shallow gravels of the aquifer to the bore. Flood modeling and physical testing demonstrated chamber flooding possible but no float alarm activation. If contamination came via wellhead, may also have occurred, then HBRC also has responsibility for not having enforced consent conditions prior.

2009-2014

Looking Ahead: what we have done and are doing Working jointly with HDC and the HBDHB on submission to Stage 2 of the Inquiry Have updated resource consent process to ensure fully NES compliant Working with HDC and HBDHB on Joint Working Group to provide safe and secure supply Undertaking audit of all registered drinking water supply bores and all private bores (including abandoned) within 2000m Reviewing State of Environment monitoring network, including surface and ground water Reviewing monitoring and compliance risk assessments Developing advice for TANK Group on managing risks to drinking water supplies for TANK Plan Change