Levin wastewater assessment of effects on marine ecological values prepared for Horowhenua District Council Technical Report
- Author
- De Luca, S.
- Year
- 2019
- Publisher / Organisation
- Boffa Miskell
- Month
- July
- Pages
- 15
- Summary
- The Levin wastewater land treatment system requires re-consenting. An understanding of the ecological values present is needed to assist in the interpretation of effects, provide guidance for the re-consenting, and provide guidance for potential wastewater land treatment upgrades and mitigation options. Boffa Miskell Ltd (BML) have been engaged to undertake an assessment of effects on marine ecology relating to the irrigation of treated wastewater to land and potential migration of wastewater through groundwater and surface water to the coast. Horowhenua District Council (HDC) is proposing modifications to the Levin WWTP land application system. The Levin WWTP produces a secondary treated effluent which is reticulated approximately 7.1 km to a storage pond and land application system at the “Pot”. The Pot pond provides storage and infiltration which enables the optimisation of the irrigation regime independent of Levin WWTP outflows. The Levin WWTP and the Pot are operated under existing resource consents (4960, 6610, 6624, 6920, 6921). Consent conditions include the collection of a range of monitoring data in the Waiwiri Stream (Aquanet Consulting Ltd, 2016). Additional monitoring data is also collected in the general area by HDC and other parties. HDC purchased the neighbouring property to The Pot, known as the Tucker Block. This is a similar land area to The Pot of approximately 100 ha. The Tucker Block is currently in pasture and leased out but also provides an opportunity for additional irrigation. This report begins (Section 2.0) by outlining the methods used to obtain information regarding the marine ecological values that are present at the coast adjacent to Waiwiri Stream mouth as well as the method for undertaking the assessment of effects. The existing values are then described for marine ecology (Section 3.0). Details are provided regarding the relevant activities (Section 4.0), and then an assessment of effects on the marine ecology associated with those activities is presented (Section 5.0). Recommendations are provided regarding measures to avoid, remedy and mitigate the potential effects of the proposal on marine ecological values (Section 6.0).