Crawford, John

Presented at WEFTEC 2023.

Titles from this speaker

Description: UV Disinfection in New Zealand's Non-codified Regulatory Environment Using QMRA for...

UV Disinfection in New Zealand's Non-codified Regulatory Environment Using QMRA for Risk Assessment

Abstract

This paper discusses an alternative, non-codified approach (as opposed to fully prescribed approaches) to wastewater effluent UV disinfection system design that allows for pragmatic, cost effective designs to be developed. New Zealand’s ‘effects based’ environmental legislation, as it applies to wastewater effluent discharges, provides for a license applicant to demonstrate the actual and likely effects (including public health) of their proposed activity and to propose measures to mitigate those effects. Quantitative Microbial Risk Assessment has increasingly become adopted in New Zealand as a means or a tool by which: a) the likely effect attributable to a particular activity in or near the environment, can be assessed, b) pragmatic discharge pathogen limits can be established, c) the disinfection system design parameters can be established d) systems developed can be tested and monitored for effectiveness. Significant savings can be made (but not always) and a fair outcome is typically achieved.

In New Zealand wastewater effluent disinfection requirements are established, plant by plant, on an assessment of effects basis rather than prescribed standards. Most effluent disinfection is by ultraviolet light irradiation. Quantitative Microbial Risk Assessment is frequently and successfully used in the risk assessment process and later in ongoing monitoring of the effects. It is also employed, indirectly, in the design and evaluation of performance of the required disinfection systems.

SpeakerCrawford, John

Presentation time

15:30:00

16:00:00

Session time

15:30:00

16:30:00

SessionNovel Applications of QMRA For Sizing Wastewater UV Systems and Identifying Shellfish Harvesting Zones

Session locationRoom S504a - Level 5

TopicDisinfection and Public Health, Intermediate Level, Municipal Wastewater Treatment Design

Author(s)

Crawford, John

Author(s)J. Crawford 1; J. Crawford 1 ;

Author affiliation(s)Beca Limited 1; Beca Limited 1 ;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159128

Volume / Issue

Content sourceWEFTEC

Word count14

Watercare's Road to Zero, Turning Short Term Targets into Actions

Abstract

This paper presents a Decarbonization Roadmap for Watercare Services Ltd (Watercare or WSL), NZ for scope 1 and 2 operational greenhouse gas emissions. This roadmap focused on achieving WSL’s GHG emissions reduction target of 50% from 2018 by 2030. They are also targeting net zero by 2050. The paper discusses the methodology for developing a robust decarbonization roadmap, highlights some of the top initiatives and describes the actions that WSL is taking as a result of this work.

This paper was presented at WEFTEC 2023 in Chicago, IL.

SpeakerBouman, Reuben

Presentation time

16:30:00

16:50:00

Session time

15:30:00

17:00:00

SessionDecarbonization Case Studies

Session locationRoom S401d - Level 4

TopicIntermediate Level

Author(s)

Bouman, Reuben

Author(s)R. Bouman 1; R. Bouman 1 ; C. Thurston 2; G Conley 3; J. Crawford 5;

Author affiliation(s)Beca, NEW ZEALAND 1; Beca, NEW ZEALAND 1 ; Watercare Services, NEW ZEALAND 2; Watercare Services, NEW ZEALAND 3; Beca, NEW ZEALAND 5;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159025

Volume / Issue

Content sourceWEFTEC

Word count11