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Chasing the Rainbow
The disharges of hydrocarbons entering water

Greater Wellington Regional Council get many calls about hydrocarbons entering streams or the CMA from the stormwater network. The trouble is, depending on the stormwater catchment size, they are incredibly hard to trace.

GWRC have some examples of Hydrocarbon discharges and various enforcement actions/ projects carried in response to Hydrocarbons.

  1. The discharge from Crown/ Government Land

    In 2018, EPO Nicola Fenn was given the project to monitor the hydrocarbons that regularly discharged from an outlet under the port into the CMA. After intense investigation, use of network mapping, dye and many different entities, we discovered a thumb size cross connection from old kiwi rail land between the separator and the stormwater chamber. 1 year on after repair, muscles grow back on the drain outlet effected

  2. The Transformer oil Incident

    In 2020, 1 week before lockdown, GWRC officers Nicola Fenn and Chris McSweeney responded to a discharge of upto 6000 litres of transformer oil discharging from an industrial transformer oil refinery, into stormwater and then into CMA. The important people to respond were the Harbour Master and Harbour Rangers, Wild Life Response unit, GWRC, TA's and the mariner. After a day spent cleaning and bunding the discharge, effects were reduced significantly as a huge quantity of oil was recovered. The perfect storm the night before drove birds out to sea or to shelter in land more reducing penguin and other protected species effect. The end result was a prosecution of the company that discharged the oil

  3. The Metals Discharge

    A sheen was seen flowing from a stormwater outlet into a freshwater stream. It was bunded and traced back to a separator that had not been cleaned due t


Thursday 8th December, 11:30am


Nikki Fenn
Environmental Protection Officer, Greater Wellington Regional Council


An environmental protection officer from GWRC - I deal with a lot of varying incidents and enforcement and I have experienced particularly a lot to hydrocarbon discharges.


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