Wastewater Discharge Feasibility Fieldwork First-flush - - PowerPoint PPT Presentation

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Wastewater Discharge Feasibility Fieldwork First-flush - - PowerPoint PPT Presentation

Jul 02, 2023 329 likes •776 views

Advice AEE Agricultural Analysis Application Approachable Assessments Assimilation Assistance Biosolids Capability Client Communications Communities Compliance Compost Consents Consultation Contamination Coordinate Council Cultural Current Data

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Advice AEE Agricultural Analysis Application Approachable Assessments Assimilation AssistanceBiosolids Capability Client Communications Communities Compliance CompostConsents Consultation Contamination Coordinate Council Cultural Current Data DegradationDesign Detention DevelopmentsDischarges Documentation Drafting

  • E. coli Ecosystems Effects Engagement Environment Equipment Evidence Excellence Experienced Expert Facilitating Farming

Feasibility Fieldwork First-flush Fit-for-purpose Flooding Fun Geology Graphs Greywater Groundwater Guidelines Handbag Hazardous Hydraulics Innovation Interpretation InvestigationIrrigation Land Landfills Landscape Land-treatment Leaching Lodge

Management

Metals Microbiology Modelling

Monitoring NES Nitrogen

Nutrients

Onsite Optimisation Organics Overseer Papers Pathogens Phosphorus Plain-english Plans Preparation Presentations Project Quality Relevant Remediation Reports Research Review Sampling Scientific Septage SludgeSoil Solutions Spreadsheets Standpipes Stormwater Strategy Support Surface Water Sustainability Systems Team Testing TimelyTreatment ValidationWastewater Water Water-balance Waterways

Wastewater Discharge

Waipukurau and Waipawa Wastewater Treatment Plants (WWTP) Community Reference Group

Hamish Lowe 30 August 2018

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  • LEI – who?
  • Wastewater discharge basics
  • Previous Investigations
  • Waipukurau
  • Waipawa

Overview

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Wastewater discharge

Reticulation Treatment Storage Discharge

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Receiving Environment

Water Land

Wastewater discharge

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Wastewater discharge

After wastewater has been treated, it needs to be discharged somewhere – it doesn’t just disappear or evaporate. The options are:

  • discharge to land
  • freshwater bodies (lakes, rivers, streams)
  • estuaries, and
  • the ocean.
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Wastewater discharge

The soils, terrain and adjacent water bodies determine the most feasible choices. The use of treatment can assist that choice. In CHB’s case, there are both land and river

  • ptions.
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Any discharge requires consideration and balancing

Cultural Social/ Recreational Financial Ecological/ Environmental

Wastewater discharge

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Wastewater discharge

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What others do

There are 330 council

  • perated wastewater

treatment plants around the country, most servicing populations <35,000 people. Smallest caters for 7 households; Waiotira, Northland; Largest 1.2 million people; Mangere, Auckland Three categories

  • f discharge
  • Land (54 M m³ of

wastewater per year)

  • Water (352 M m³ of

wastewater per year)

  • Combined land and

water (59 M m³ of wastewater per year)

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What others do

1% 75% 11% 13%

NZ Wide Treatment Plant Discharges

Unknown Water Discharges Land Discharges Combined Land/Water Discharges

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Legend

Cities>30,000 people Towns <5,000 people Settlement <750 people Discharge Method Irrigation to land River/stream Ocean

Wastewater discharge

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What others do

21% 4% 75%

NZ Surface Water Discharge Methods

River Unknown Ocean

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What others do

2% 12% 0% 36% 4% 46%

NZ Land Discharge Methods

Unknown Trees Dairy Grazed Cut & Carry High Rate

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Cultural vs tangata whenua

Consider states

Waiora to Waimate

Allows for tapu to noa Papatuanuku

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100 % Land 100 % Water

Irrigation - High-rate Irrigation - Non-deficit Irrigation - Deficit Overland - Rock trench Rapid Infiltration Pipe to Water Overland - Wetland

Wastewater discharge

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River Wetland Forestry Small Holdings Large Holdings

Are combinations possible or needed?

Water Land

Direct to Water Indirect to Water Stay on Land

Wastewater discharge

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Principles of Land Discharge

Land treatment of waste utilises the biological, chemical and physical properties of the land to further treat solid and liquid wastes and/or allow for land passage before reaching the underlying groundwater environment.

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Principles of Land Treatment

Land treatment is philosophically and practically distinct from land disposal.

Land treatment seeks to utilise the environment to its maximum extent treat the waste, and in so doing may also seek to improve the environment through the characteristics of the waste. Land disposal seeks only to dispose of the waste, using the land as a mechanism to allow the waste to enter the environment with limited or no treatment.

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Land Treatment systems

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Land Treatment systems

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Land - Investigations

  • How close is the land to the WWTP and how many sensitive neighbours are nearby?

Location

  • Gentle slopes or flat land at similar height to WWTP are ideal.

Terrain and elevation

  • Water holding capacity, drainage rate, and particle size or soil type will determine loadings

rates.

Soil properties

  • will wastewater irrigation integrate with the current land use (eg reserve, farm, or forestry) or

will the land use need to change to accommodate the wastewater irrigation? How will harvesting or stock grazing regimes integrate with irrigation regimes?

Land use

  • how much land is available after subtracting buffers and unsuitable land?

Land area

  • what are the normal and extreme ranges of rainfall, soil moisture deficit, and wind for each

month and year? How will these variations limit irrigation design and operation?

Climate

  • Cultural, community, society

Values

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Land - System design

  • Examples are subsurface dripper lines, fixed

irrigators, travelling irrigators, border dyke or infiltration basin, and (artificial) wetland basin.

Method of discharge

  • Choices are deficit, non-deficit, rapid discharge

for disposal to groundwater or wetland, and land passage prior to entering waterways.

Application rate and purpose

  • What seasons, weather or soil moisture

conditions will restrict or prevent discharges (eg wet soils, heavy rain, or strong winds)?

Timing of discharges

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Land - System design

  • How much storage volume will

be needed? Where will an additional pond be located?

Storage for deferred discharges

  • What will happen to excess

wastewater volumes and what limits would be appropriate?

Emergency or large storm contingencies

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Land - System design

In developing a land discharge system there are a series of basic design parameters which need to be considered.

Basic design parameters:

Cultural acceptability Hydraulic Loading Organic Loading Nutrient Loading Pathogen Loading

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Principles of Water Discharge

Discharge at a rate and composition that is within the seasonal assimilative capacity of the waterway.

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Water - Investigations

  • How close is the land to the WWTP to the waterway

Location

  • Fast flowing, slow moving

Characteristics

  • How does flow go up and down and how does this match

wastewater flows

Flow seasonality

  • Contact recreation, stock water

Water use

  • What is the level of nutrient enrichment existing and can

more be accommodated

Chemical status

  • What lives there – macroinvertebrates, fish, algae

Biological status

  • Cultural, community, society

Values

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Water - System design

  • Direct, indirect – pipe, near bank, gallery

Method of discharge

  • Is it culturally acceptable and will

nutrient enrichment influence quality and habitat

What is the impact

  • How is volume and treatment level

adjusted to reflect flow and limitations

Timing of discharges

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Water - System design

  • Can storage be used to avoid

low flow discharges?

Storage for deferred discharges

  • What will happen to excess

wastewater volumes and what limits would be appropriate?

Emergency or large storm contingencies

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Water - System design

In developing a water discharge there are a series of basic design parameters which need to be considered.

Basic design parameters:

Cultural acceptability Hydraulic Loading Organic Loading Nutrient Loading Pathogen Loading

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CLAWD

  • What criteria will be used to determine when the best

times will be to discharge to these environments and how much is to be discharged each day? How will they be prioritised and balanced?

Criteria for selecting Combined Land and Water Discharges

  • How much storage volume will be needed for times

when neither environment (land and water) can receive the discharges? Where will an additional pond be located?

Storage for deferred discharges

  • What will happen to excess wastewater volumes and

what limits would be appropriate?

Emergency or large storm contingencies

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Benefits and Opportunities

Community should decide Can it be expanded One system or multiple Is water a resource

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Previous investigations

  • Irrigating the existing quality effluent on to

forests that had been planted by the Regional Council at Waipawa and Waipukurau.

  • Storing effluent when the forests were not

capable of accepting the spray irrigation.

  • Discharging excess stored effluent into the

Tukituki and Waipawa Rivers at times when the river flows were 3 times the median flow.

In 2007 the Hawke’s Bay Regional Council and CHBDC together investigated a forest treatment

  • ption. This

consisted of:

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Waipukurau

Image Credit: Sarah Platt

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Waipukurau

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Waipukurau

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Waipukurau

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Waipawa

Image Credit: Sarah Platt

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Waipawa

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Waipawa

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Waipawa

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Waipawa

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Your choice

Water Land

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www.lei.co.nz | Palmerston North Christchurch Wellington | office@lei.co.nz

Advice AEE Agricultural Analysis Application Approachable Assessments Assimilation AssistanceBiosolids Capability Client Communications Communities Compliance Compost Consents Consultation Contamination Coordinate Council Cultural Current Data Degradation Design Detention Developments

Discharges

Documentation Drafting E. coli Ecosystems Effects Engagement Environment Equipment Evidence Excellence Experienced Expert Facilitating Farming Feasibility Fieldwork First-flush Fit-for-purpose Flooding Fun Geology Graphs Greywater Groundwater Guidelines Handbag Hazardous Hydraulics Innovation Interpretation Investigation

Irrigation

Land Landfills Landscape Land-treatment Leaching LodgeManagement Metals MicrobiologyModelling Monitoring NESNitrogen Nutrients Onsite Optimisation Organics Overseer Papers Pathogens Phosphorus Plain-englishPlans Preparation Presentations Project Quality Relevant Remediation Reports Research ReviewSampling Scientific Septage SludgeSoil Solutions Spreadsheets Standpipes Stormwater Strategy Support Surface Water Sustainability Systems Team Testing TimelyTreatment ValidationWastewater Water Water-balance Waterways