Official Information Request - Wastewater overflows

Sent: Wednesday, 9 February 2022 10:40 AM
Subject: LGOIMA RLC Wastewater overflows

I refer to your LGOIMA request of 11 January 2022 regarding wastewater spills and provide the following response.

Please also find attached a spreadsheet that provides details on the date, location, asset involved, cause, weather conditions, and whether land or waterway was impacted.

• How many wastewater spills have there been in the Lakes area during each of the past three years?
  -2019/20 – 56
  -2020/21 – 37
  -2021/22 to date – 16
• Please provide a breakdown for each spill, including the specific location, date, cause of the spill, estimated amount spilled, land area and/or waterway impacted, how it was impacted (e.g. swim ban) and how long it was impacted.
  Details regarding how the environment was impacted and for how long are not recorded in a way that can be collated and for some events may not be recorded at all. Determining whether these details exist for each overflow record will require extensive investigation which may incur a charge.
  Council and its contractors respond in accordance with the Regional Best Practice Guide for the Management of Wastewater Overflows which was developed by Council, together with Bay Of Plenty Regional Council and other district councils in the region.
  Council also follows advice from Toi Te Ora Public Health and Bay Of Plenty Regional Council about the appropriate response i.e. swim/recreation ban, signage etc. The standard length of impact is about 48 hours (the same advice for swimming after periods of heavy rain) however, Council will carry out regular testing to ensure the impact on the environment is reduced to a level that is acceptable for public use before any measures are lifted.
  In a recent example that did not follow a typical 48 hour period, an overflow into the lake resulted in a recreation/swim ban being in place for longer than the standard 48 hours. This was due to elevated levels of contamination remaining in the lake for longer than expected. However, following source testing of the lake and nearby stream it was found that the elevated levels were due to bird/animal contamination, not human.
• How much has wastewater spills cost the council in each of the past three years? If possible, please breakdown these costs into the appropriate categories. (costs for testing, staff overtime, consulting, etc)
• Costs for overflow responses are not itemised. Responses to overflows are included in the lump sum contract payment provided to TRILITY for the ongoing management of the network. Contracts for the years prior to Council engaging TRILITY were managed the same way.
• Generally, how do the number of spills seen in these three years compare to previous years and why? Meaning, does the council consider there are fewer recently, or more, and why?
• Due to updates and improvements in reporting we do not hold comparative data. Council would need to see an ongoing trend in the instances of overflows and their causes to understand the underlying reason for any significant changes in trend.
• Key information:
• Rotorua Lakes Council is diligent in reporting overflows. Even when there is doubt that an overflow has reached a waterway Council will report via the appropriate channels. We have a partnership with mana whenua and we strive to be as transparent as possible with our partners, local health authorities and the wider community.
• Rotorua has an extensive wastewater network of 80 pump stations, and more than 500km of sewer main and 8000 man holes. There is always a risk that there could be a network/pipeline fault or damage that causes wastewater flow obstructions.
• Like most of the country’s wastewater networks operated by TLAs, our annual Key Performance Indicators (KPIs) recognise and reflect that there is such an expectation and that some overflows will occur, but stipulate maximum occurrences per annum for faults. In our KPIs this is at no more than 10 faults per 1000 connections with trends indicating that we are well within these limits. We of course always endeavour to keep these to a minimum, and respond effectively to minimise their effects.
• As you will see from the data a fair amount of blockages that have caused overflows are a result of foreign objects making their way into the network rather than a network fault. Some examples of objects that have been encountered over the years are:
  -A hedgehog
  -Childs toy Tonka truck
  -Cutlery
  -A pig’s head
  -5 litre oil can
  -Building materials
  -Cleaning wipes
  -Fatbergs
• In recent years Council has increased its proactive activities to minimise the risk of overflows from the network. These activities include: -Increase of pipe water blasting from annually to quarterly in some areas -CCTV inspections of every gravity main within the network (in progress) -Increase in personnel (via TRILITY) to manage assets and carry out network inspections -Business improvements in the way of data recording and network monitoring

You have the right to seek an investigation and review by the Ombudsman of this decision. The Ombudsman’s Office can be contacted by calling 0800 802 602, emailing info@ombudsman.parliament.nz, online at www.ombudsman.parliament.nz, or by post to The Ombudsman, PO Box 10152, Wellington 6143.

Publication of responses to LGOIMA requests

Please note: Our LGOIMA responses may be published on the Rotorua Lakes Council website after they have been responded to, with requesters’ personal details withheld. If you have any concerns about this please contact the Council on info@rotorualc.nz

Ngā mihi