District Council sends report to regulator on wastewater spill into Raglan Harbour

Update 07.08.15, 4.49pm Media advisory from Waikato District Council – All clear for Raglan Harbour

Please note – the ‘no shellfish collection’ signs have been removed from Raglan Harbour this afternoon (Friday 7th August).

Waikato District Council has sent a report to the Waikato Regional Council, its regulator, on the wastewater spill into Raglan Harbour. The spill occurred in the Moonlight Bay area off Greenslade Rd, Raglan for a few days in late July and was stopped on the 1st August.

The report says it was caused by roots growing in a sewer pipe that blocked the pipe. The District Council says that:

• Waters Assets Team will create a programme with all manholes within 100m of a waterway to be inspected by WDC Operations team annually.
• CCTV wastewater mains within the area to identify risks in the system and make appropriate repairs.
• Individual response plans for high priority areas i.e. Greenslade, Lorenzen, Bayview, Marine Parade – i.e. relating to access to individual parts of system and risk tables, may be considered.

Full text of the report follows:

1. Purpose

To document the events surrounding the minor wastewater overflow from a manhole near 102a Greenslade Road, Raglan.

2. Site Description

The overflow occurred at the manhole near 102a Greenslade Rd as shown below.

3. Incident Summary

• At 16.40pm on Saturday 01/08/15 Answer Services received a call from Mrs Claiborne a resident on Greenslade Rd that a manhole on the track between 102 & 104 Greenslade Rd was overflowing and had been for three days.
• The wastewater overflowing from the manhole travelled approximately 20m down the track to the Raglan harbour.
• The wastewater overflow was approximately equal to 1 metre per hour when notified but may well have been a lot less during the three days leading up to that point as it had only been called in when the issue became more apparent.
• A Serviceman arrived on site at 5.40pm on Saturday 01/08/15 and identified that a jetting unit was needed to clear the blockage properly. Due to issues with access to the site the Serviceman proceeded to rod from the manhole and partially removed the roots causing blockage to get the system flowing overnight. This temporarily mitigated against a further overflow.
• The Serviceman returned to site with Insight services on Sunday 02/08/15 at 09.30a.m. and found better access through a neighbour’s property to jet the wastewater main completely. Once this was complete the affected area was cleaned and sanitised.
• WRC were informed of the wastewater spill via the 0800 number and via email on Saturday 01/08/15
• Other stakeholders including the Health Protection Officer and community groups were informed via email on the afternoon of Saturday 01/08/15.
• Signage (No shellfish gathering or swimming) was put in place on Monday 03/08/15 at the point of entry and at access areas and will be kept in place for 5 days.
• A media release was distributed on 03/08/15.
• High flush and dilution processes occurring in the harbour during winter along will ensure that the any public health risk resulting from the minor spill is minimal.
• Samples will be taken over three days so that test results can be used to present an indication of compliance with the Microbiological Water Guidelines for Marine and Fresh Water Recreational Areas; all in the context of run off from the catchment entering the harbour.

4. Issues Identified

• Public response to overflowing manholes can differ and because of the importance of early response to wastewater overflows WDC may need to improve public education on this topic.

5. Recommendations

• Waters Assets Team will create a programme with all manholes within 100m of a waterway to be inspected by WDC Operations team annually.
• CCTV wastewater mains within the area to identify risks in the system and make appropriate repairs.
• Individual response plans for high priority areas i.e. Greenslade, Lorenzen, Bayview, Marine Parade – i.e. relating to access to individual parts of system and risk tables, may be considered.