Mangere Wastewater Mangere Wastewater Mangere Wastewater Mangere Wastewater Mangere Wastewater Mangere Wastewater Mangere Wastewater Mangere Wastewater Treatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment PlantTreatment Plant

CEE 491CEE 491Sean SchultzSean Schultz

Lampros MitropoulosLampros MitropoulosScott HonjiyoScott Honjiyo

Presentation ContentsPresentation ContentsPresentation ContentsPresentation ContentsPresentation ContentsPresentation ContentsPresentation ContentsPresentation Contents

�� Project overviewProject overview

�� Project use and Project use and benefitsbenefitsbenefitsbenefits

�� Technical issues Technical issues and innovationsand innovations

�� Social problems Social problems and policy issuesand policy issues

Project overviewProject overviewProject overviewProject overviewProject overviewProject overviewProject overviewProject overview�� Location: Auckland, New ZealandLocation: Auckland, New Zealand

�� Plant was first opened in 1960Plant was first opened in 1960

�� Oxidation pond system covers Oxidation pond system covers more than 500 hectares (app more than 500 hectares (app 1,236 acres) 1,236 acres)

�� Began upgrade construction in May of Began upgrade construction in May of 19981998

�� Began upgrade construction in May of Began upgrade construction in May of 19981998

�� Opened on April 4, 2003 by Prime Opened on April 4, 2003 by Prime MinisterMinister

�� Run by Run by WatercareWatercare Services limited Services limited (Public)(Public)

�� Price:Price:

�� $450 Million$450 Million

Project UsageProject UsageProject UsageProject UsageProject UsageProject UsageProject UsageProject Usage

�� LandLand--base water treatment systembase water treatment system

�� Upon final filtering and UV Upon final filtering and UV disinfection, the flow is disinfection, the flow is transferred to transferred to PuketutuPuketutuIsland, where the channel Island, where the channel feeds into the 17 hectare feeds into the 17 hectare feeds into the 17 hectare feeds into the 17 hectare intertidal storage basin.intertidal storage basin.

�� Has the capacity to cater to Has the capacity to cater to Auckland’s growing capacity.Auckland’s growing capacity.

�� Provide significant environmental Provide significant environmental benefits to benefits to ManukauManukau HarborHarbor

�� Better quality effluent dischargeBetter quality effluent discharge

Positive ImpactsPositive ImpactsPositive ImpactsPositive ImpactsPositive ImpactsPositive ImpactsPositive ImpactsPositive Impacts

�� Improves the EnvironmentImproves the Environment

�� Provides bathing water quality to Provides bathing water quality to discharge into harbordischarge into harbor

�� 500 hectares of oxidations ponds and 500 hectares of oxidations ponds and sludge lagoons returned to a natural sludge lagoons returned to a natural harbor environmentsharbor environments

�� 13 km of coastline also improved13 km of coastline also improved

Biggest coastal restoration effort in New Biggest coastal restoration effort in New �� Biggest coastal restoration effort in New Biggest coastal restoration effort in New ZealandZealand

�� Odor Boundary established and upheldOdor Boundary established and upheld

�� Treatment cycle reduced from 21 days to 13 Treatment cycle reduced from 21 days to 13 hourshours

�� Haven for thousands of migrating birdsHaven for thousands of migrating birds

�� Bird roosts built for birds resting while tide covers their feeding Bird roosts built for birds resting while tide covers their feeding groundsgrounds

Technical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and InnovationsTechnical Issues and Innovations

�� Transformed the old Mangere Wastewater Treatment PlantTransformed the old Mangere Wastewater Treatment Plant

�� 5 year project, treatment processes have been replaced5 year project, treatment processes have been replaced

�� Plant reduces the treatment cycle for wastewater from 21days Plant reduces the treatment cycle for wastewater from 21days �� 13 hours 13 hours

■ Fine screens: From 19mm� 3mm gaps between barsExtraction of inorganic material has increased from 1�5 tonnes/day

■ Pre-aeration tanks

■ Primary sedimentation tanks � 12 tanks

Primary TreatmentPrimary TreatmentPrimary TreatmentPrimary TreatmentPrimary TreatmentPrimary TreatmentPrimary TreatmentPrimary Treatment

■ Primary sedimentation tanks � 12 tanks (70x12m)

■ Upgraded � Strengthening, re-coating the tank surfaces

■ 2 products ( Sludge & wastewater)

■ Gravity thickening

■■ New New processprocess��BiologicalBiological Nutrient Removal (BNR)Nutrient Removal (BNR)

■■ 9 Reactor/Clarifiers (D=77m)9 Reactor/Clarifiers (D=77m)

■■ Capacity for 200,000 people/unitCapacity for 200,000 people/unit

■■ Reactor Reactor �� 4 aerobic & 4 anoxic compartments4 aerobic & 4 anoxic compartments

■■ Clarifier Clarifier �� 2 products (Activated Sludge & wastewater)2 products (Activated Sludge & wastewater)

Secondary TreatmentSecondary TreatmentSecondary TreatmentSecondary TreatmentSecondary TreatmentSecondary TreatmentSecondary TreatmentSecondary Treatment

■■Solid waste Solid waste �� Dissolved air flotation Dissolved air flotation

(DAF) thickeners (DAF) thickeners

■■ 7 Anaerobic sludge digesters 7 Anaerobic sludge digesters ■■ 7 Anaerobic sludge digesters 7 Anaerobic sludge digesters (15 days)(15 days)

■■ Dewatering plant (100 Dewatering plant (100 �� 300 300

wet wet tonnestonnes/day)/day)

■■ Effluent from clarifierEffluent from clarifier

■■ Filtration (10 massive filters)Filtration (10 massive filters)■■ Particles > 15µm (=Particles > 15µm (=1515 1010−6−6 m) m)

■■ UV disinfection UV disinfection plantplant��largestlargest in the world in the world (10,000reduction in viruses)(10,000reduction in viruses)■■ 12 parallel channels12 parallel channels■■ 7776 UV lamps7776 UV lamps

■■ Discharge (300,000mDischarge (300,000m22/day)/day)

■■Treatment plant required to be Treatment plant required to be fully operational during fully operational during constructionconstruction

■■Local Government Act Local Government Act ––■■Local Government Act Local Government Act ––Statement of Corporate IntentStatement of Corporate Intent

■■Nine separate management Nine separate management plansplans

■■Resource Management Act Resource Management Act ––Very strict conditions such as:Very strict conditions such as:

■■ 16 species in New Zealand.16 species in New Zealand.■■ Huge nuisance factor.Huge nuisance factor.■■ Monitoring and surveys required.Monitoring and surveys required.■■ Use of control sprays Use of control sprays –– Section 15 of Resource Section 15 of Resource

Management ActManagement Act■■ “Code of Practice for the Management of “Code of Practice for the Management of

Agrichemicals”Agrichemicals”

■■Final Filtering and Final Filtering and UV Disinfection.UV Disinfection.

■■Runs along main Runs along main effluent channel.effluent channel.effluent channel.effluent channel.

■■Water, after Water, after upgrade, is of high upgrade, is of high enough quality for enough quality for shellfish and even shellfish and even swimming. swimming.

■■ Treaty of Waitangi Treaty of Waitangi Claim.Claim.

■■ Maori People.Maori People.

■■ Brought back Brought back previously destroyed previously destroyed fishing grounds.fishing grounds.

--OruarangiOruarangi Creek.Creek.--OruarangiOruarangi Creek.Creek.

--Blocked in 1960’s by Blocked in 1960’s by Auckland’s sewage Auckland’s sewage

system.system.

--By 2005, water once By 2005, water once again flows to the again flows to the

Maori.Maori.

Design lifeDesign life

Base flow to the treatment plantBase flow to the treatment plant

Excess storm flows to WTPExcess storm flows to WTP

Theoretical maximum capability of the Theoretical maximum capability of the system system

Treated wastewater discharged from plantTreated wastewater discharged from plant

30 years30 years

9 cumecs9 cumecs

5 cumecs5 cumecs

16.5 cumecs16.5 cumecs

285,000 cubic 285,000 cubic metresmetres per per

Key StatisticsKey StatisticsKey StatisticsKey StatisticsKey StatisticsKey StatisticsKey StatisticsKey Statistics

Treated wastewater discharged from plantTreated wastewater discharged from plant

Capacity of intertidal storage basin Capacity of intertidal storage basin

Capacity of discharge pumps Capacity of discharge pumps

Process Process biosolidsbiosolids generated by plant generated by plant

285,000 cubic 285,000 cubic metresmetres per per dayday

(17 ha) 370,000 cubic (17 ha) 370,000 cubic metresmetres

25 cubic 25 cubic metresmetres per secondper second

100,000 100,000 tonnestonnes per annumper annum

Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?