WASTEWATER CONSENT RENEWAL IN THE MARLBOROUGH SOUNDS

A homeowner in the Marlborough Sounds needed to renew the discharge consent for an existing onsite wastewater system.

The remote coastal site was not connected to public sewer and relied on a secondary treatment system with pump dosed drip irrigation across a steep, vegetated slope.

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RISEN inspected the system, reviewed the design and prepared the consent renewal application, giving the homeowner one point of contact for the engineering assessment and supporting documents.

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THE TASK

The system served a three bedroom dwelling and had been installed more than a decade earlier. We needed to assess whether the treatment unit, irrigation field and site conditions remained suitable for continued use.

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The assessment included a review of the original design, Council records and as built information, followed by a detailed site inspection.

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All treatment chambers were opened and checked. The blower, irrigation pump and high level alarm were tested and found to be operating correctly. The tanks were in good condition, with no signs of leakage, structural damage or infiltration.

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TESTING THE IRRIGATION FIELD

Several hundred litres of water were passed through the system to activate a dose cycle.

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The full irrigation field was inspected across the steep, vegetated slope. Distribution was even, with no ponding, leakage, surface seepage or odour observed during the inspection.

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The established vegetation, sun exposure and coastal wind also provided good conditions for evapotranspiration and moisture recovery between doses.

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UPDATING THE DESIGN ASSESSMENT

RISEN completed soil testing within the land application area using the AS/NZS 1547:2012 method.

The testing supported a Category 5 light clay classification.

 

The design review found that the installed irrigation area remained closely aligned with the assessed requirement for the dwelling and expected occupancy.

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The environmental risk assessment also considered slope, groundwater, coastal water, flood exposure, vegetation and setbacks. The system was assessed as presenting a low overall risk, provided regular servicing continued.

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THE OUTCOME

RISEN prepared the full consent renewal package, including:

• engineering review and site inspection

• soil testing and suitability assessment

• environmental risk and setback review

• wastewater loading certificate

• maintenance schedule

• assessment of environmental effects

• Council application documents

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The review supported continued use of the existing system without major modification, subject to regular servicing. The homeowner received the engineering assessment and documents needed for the Council renewal application.

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NEED TO RENEW AN ONSITE WASTEWATER SYSTEM CONSENT?

RISEN provides complete onsite wastewater resource consent renewal support across Marlborough, from inspection and engineering assessment through to the Council application.

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Or contact us to discuss further.

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