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Sewer separation

FRESHWATER QUALITY PROGRAME OF WORK

(Separation of Services)

Background to the challenges ahead

Wastewater and stormwater in Greymouth, Cobden and Blaketown have historically travelled through a single common drainage system from your property.

This method of wastewater disposal relied heavily on any wastewater combining with storm or rainwater to dilute the waste. This meant untreated wastewater discharged into the Grey River and other streams and waterways. This process has been unacceptable for a number of decades now and our community has invested heavily to ensure new wastewater systems and treatment processes, have been installed.

Health and environmental standards have significantly improved since the installation of the older combined system, and it is unacceptable for untreated wastewater to go into our freshwater systems. The quality of our rivers and streams, ecological harm and health risks to members of the community who come into contact with contaminated water are all impacted by untreated wastewater getting into our freshwater systems.

Grey District Council also requires resource consent to discharge from its network to natural waterways. Stringent water quality standards mean it is becoming increasingly difficult to meet the requirements of the resource management act under the current system. This means consents may not be renewed in the future or that fines may be imposed on the Council if water quality standards are not met.

Improving water quality and protecting water ecosystems is important for future generations. Mahinga kai, a food source, is significant to tangata whenua and many of our communities use our rivers, lakes and streams for food gathering.

It is now essential that all property owners take action to ensure the separation of their stormwater and wastewater services.

Twenty years ago, in 2004 Council installed its stage 1 treatment plants in Greymouth and Cobden which provided a significant step forward and started short term treatment of the combined dry weather flows. This saw an immediate improvement for our environment.

Since then, our community has been working through the installation of a separated wastewater system. Council moved through streets installing a new pipe network and lateral to property boundaries. Residents then had a set timeframe to undertake their onsite separation and connect to the new service.

Overall, there has been a significant investment made to provide the infrastructure that enables the separation of wastewater from freshwater, including comprehensive wastewater mains construction, pump stations and the construction of the Preston Road wastewater treatment plant.

Council is acutely aware of the significant pressure this necessary work, places on many property owners. Council has exercised a great deal of leniency in enforcing the requirement to undertake work. Council is now faced with significant pressure to ensure its compliance with resource consents and each property must carry out their work to support compliance.

Council is planning a works programme to address the separation and connection of those properties that are not separated by July 2025 .

Council urges all remaining properties to make their own arrangements for completion of separation works, taking advantage of the Council offer to fund building consent fees (prior to 1 July 2025).

Drainage configurations

Not all situations are the same, and a number of drainage configurations exist on properties in the district. We have explained the different drainage configurations that exist in the district below. If you’re not sure how your system is configured, a suitably qualified plumber of drainlayer can help determine the situation that applies to your drainage.

Not separated and not connected

Both wastewater from sanitary fixtures (toilets, sinks, washing machine etc.) and storm or rainwater from rooves and paved surfaces are connected to a single drain which discharges to the original combined wastewater/stormwater system.

This system is now typically the stormwater only system. In this case the property owner will most likely need to install new wastewater only drainage from the house and redirect their wastewater discharges to the new wastewater only lateral provided. The original combined pipework remains as stormwater only collection and discharge.

Separated but not connected

Onsite work to separate your wastewater and stormwater may have already been completed or was done at the time the house was built. The redirection of the wastewater only discharge to the new wastewater lateral is required, to be completed by the property owner.

Sewer discharging to stormwater (original combined system)

In some streets, Council opted to retain the original combined sewer and stormwater system as the new wastewater only system. This means a new stormwater system would have been installed in your street and new stormwater only lateral provided to your property boundary. In this case, a new separated system is required on your property to ensure that the stormwater is redirected to the new stormwater only service provided.

General note

In all cases, property owners should be working towards installing new sewer only pipes to ensure security of that pipework. The older, typically earthenware private property pipework can be compromised due to age, meaning that ground water can enter the pipeline adding to flows that need to travel through the larger network and ultimately be treated. Across numerous properties groundwater can add significant amounts of flow to the network and compromises the treatment process.

If property owners choose to keep the original internal drainage for their wastewater only drainage, the pipework will need to be tested at the time of the separation. If testing fails, then work will be required to ensure a pass test can be achieved.

You can confirm this by arranging for a drainlayer to complete testing and provide a written statement to Council. This will confirm:

  • The wastewater discharge from the property is separated and connected to the new wastewater system; and
  • No stormwater discharge from the property is connected to or draining into the wastewater system and that stormwater is being discharged to an approved location. In most cases this will be the original combined wastewater/stormwater system, which is now the stormwater only system.

Once Council has received this information, staff will review it and may ask the property owner some questions or ask for clarification. Once confirmed, Council will update its records.

If you’ve received a letter asking you to separate services, then Council records show that your property requires separation work to ensure compliance with separation and connection requirements.

If work has been completed on your property legally, then Council will have a record of this on its systems through a building consent. If you still believe that work has been completed, potentially without a building consent or through other means, please collate the information and meet with Council to discuss and confirm.

A suitably qualified plumber or drainlayer can carry out a dye test on your drains to determine the configuration of your drainage and where it is connected. Your plumber or drainlayer will need to discuss this with Council as opening network access chambers in the road reserve requires approval and sometimes traffic management. Council also needs to ensure that chambers are secure/safe during an inspection and are then closed/secure once the test has been completed.

In many cases, property owners have had years to undertake this work. Council now requires property owners to complete their onsite separation work and connect their individual wastewater and stormwater discharges to the correct system by 30 June 2025. Beyond this date, Council will commence undertaking this work across the district on behalf of the property owner.

Most property owners engage a qualified plumber or drainlayer to do all the work for them but sometimes we are asked if an owner can do their own work. Where safe to do so, property owners can assist their registered drainlayer by digging trenches. Your drainlayer will be able to provide you with some detail around the trench needs to ensure you dig this correctly. Under the Plumbers, Gasfitters and Drainlayers Act, drain laying can only be done by licensed tradespeople.

Once the pipework is installed by your drainlayer, inspection is completed, and pipework covered by your drainlayer. Where safe to do so, there may be the opportunity for the property owner to backfill the trench and put back lawns, gardens and paving if required. You should talk to your drainlayer about opportunities to reduce costs on your particular property if that is of interest to you.

Yes, a building consent is required to complete this work. The good news is that your drainlayer will be able to help you through this process and in many cases complete this application on your behalf.

Building consents typically cost between $500 and $900 for separation works. This includes inspections. On completion a code compliance certificate is issued by Council to verify that work was completed in accordance with the building consent.

To support property owners Council has agreed to fund the building consent costs for your property’s separation works, as long as you apply and gain the building consent before 30 June 2025. We encourage property owners to take advantage of this support.

If your drainlayer can’t complete the work before July 2025 but you would still like to arrange for the work to be completed by your drainlayer, you can contact Council to discuss your individual situation. Council will look to gain confirmation form you and your drainlayer of the date when work will be completed. Council will review this against its work programme and confirm if this is suitable. Once a confirmed date is in place, your drainlayer will need to ensure work is completed in line with this.

Council is aware that some of the major banks have low interest loans available to support work of this nature. You can contact your bank to see if a suitable finance option is available to you.

Council will continue to investigate options and update residents if additional opportunities arise to help with costs or financing of costs.

Beyond 30 June 2025, Council will start engaging contractors to complete the separation works on private property, engaging a contractor to do a number of properties at the same time. This will help to keep costs as low as possible.

Council will then recover costs from each property owner through a targeted rate in the following rating year.

The targeted rate will be added to your rates, over one year.

  • Ideally, property owners will take up Council’s offer of a nil cost building consent, engage a registered drainlayer and complete the required works by 30 June 2025.
  • Beyond 30 June 2025 Council will engage suitably qualified contractors/registered drainlayers to start the process of completing work on each private property.
  • Given the number of properties still to be connected, we expect this work will take between 6 and 8 years to complete.
  • Once work is completed on your property, Council will put in place a targeted rate on your property to recover associated costs.
  • Once all properties are separated and connected the community will have a compliant wastewater collection and treatment system. Discharges to waterways and the Grey River will be free of wastewater for the community and future generations to enjoy.

Council staff are supporting the plumbers and drainlayers to carry out this essential work. Council will soon meet with interested drainlayers and plumbers within the district to discuss the process from here and ensure all interested parties know how the process will operate.

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