Air pollution in Christchurch: defining and addressing the issues Andy Sturman Geography Department University of Canterbury

Recommended reading Chapter 3 of the proposed Canterbury Natural Resources Regional Plan (see now/can-homepage.htmlhttp:// now/can-homepage.html) now/can-homepage.html See also list of references on the Geography Teachers’ web site (on the Geography Department home page)

Outline l Defining the air pollution problem in Christchurch –How bad is it? –What are the main causes? l Addressing the air pollution problem –Air quality management –Planning issues

A typical winters evening! “The grey-brown blanket is coming down over the city every few nights, but debate continues about how bad the problem is, and how best to tackle it. It generates more heat than several open fires.” (The Press, Aug 5, 1998:7)

Defining the air pollution problem in Christchurch: How bad is it?

Air Quality Guidelines

Air Quality Assessment Criteria (Ministry for the Environment)

Peak PM hour average concentrations

Responsibility for monitoring air quality l Since the Resource Management Act (1991), Environment Canterbury is responsible for monitoring air pollution in Christchurch (and the rest of Canterbury) l The main monitoring site is at St Albans (since 1988), measuring: –sulphur dioxide, carbon monoxide, nitrogen dioxide, lead and suspended particulate –meteorology (wind speed, wind direction, temperature)

What are the results of monitoring? l Pollutants which most commonly exceed guidelines in Christchurch are: –suspended particulate (PM 10 ) –carbon monoxide (CO) l Seasonal trends l Diurnal trends

Record of PM 10 exceedences Results for St. Albans, CRC (2003)

Record of CO exceedences Results for St. Albans, Ecan (2003)

Monthly average values for St Albans

May-August hourly average values for St Albans

Day-to-day variations – winter 2001

Spatial pattern of TSP (May-August 1981)

What are the main causes? l Sources of air pollution l Environmental factors

Sources l What are the main sources of air pollution in Christchurch? l What controls emssions? –spatially and temporally l Estimating emissions from sources –emissions inventories –source testing

The 1996 survey by the CRC concluded: l 82% of PM 10 emissions result from domestic solid fuel heating. l main sources of CO are motor vehicles. l main emitters of particulates are open fires, old woodburners and coal burners. l There are approximately 15,500 open fires, 3,500 closed coal burners and 31,000 woodburners.

Estimated emissions of PM 10

Updated for 1999 and 2001

Sources of PM 10 in Christchurch (1999) Domestic heating 90% Industry 7% Transport 3%

Breakdown of domestic heating by burner type (1999) Open fire - wood Open fire - coal Pre 89 woodburner woodburner Post 1992 woodburner Multi-fuel burner - wood Multi-fuel burner - coal 5,700 households 15,600 households 10,000 households 5,000 households 17,800 households 2,200 households 1,700 households

Contribution to PM 10 emissions from domestic heating (1999)

Estimated home heating costs CRC (1997)

Environmental controls of air pollution l Low temperatures l Strong temperature inversions l Low wind speed l Terrain-induced airflows

An overview of Christchurch’s air pollution problem (The Press 2002)

Temperature Inversion Effects Whiteman (2000)

Mixing Depth Whiteman (2000)

The mixed layer over Christchurch

Convergence of nocturnal airflow over Christchurch

Different diurnal air pollution regimes

What are the effects of air pollution in Christchurch? l Controversy over effects –difficult to measure l Estimated effects of suspended particulates (CRC 1996) –annual loss of 82,000 work days –21-29 hastened deaths of those at risk –more allergies and asthma attacks l Carbon monoxide effects unknown

Summary l Christchurch has a serious air pollution problem l main pollutants of concern are PM 10 and CO (from home heating and vehicles) l bad episodes are associated with winter anticyclones with clear skies and light winds (inversions/stagnation) l air pollution can have serious health consequences, but they are difficult to prove

Addressing the air pollution problem l Air quality management l Planning issues

Air quality management: the Regional Air Plan

Main elements of the Air Plan Not a total solid fuel ban (allows replacement of existing burners) Not a total solid fuel ban (allows replacement of existing burners) Prohibit use of open fires from 2006 Prohibit use of open fires from 2006 Prohibit burners into new houses or existing houses using other heating methods from 2003 Prohibit burners into new houses or existing houses using other heating methods from 2003 Set a tighter emission standard of 1.0 g/kg and 65% efficiency to apply from 2004 Set a tighter emission standard of 1.0 g/kg and 65% efficiency to apply from 2004 Phase out non-complying enclosed burners from 2008, 15 years after installation Phase out non-complying enclosed burners from 2008, 15 years after installation

Main elements of the Air Plan Provide exemptions for a list of heritage buildings and in emergency situations Provide exemptions for a list of heritage buildings and in emergency situations Provide financial incentives and assistance for insulation and clean heating (The Clean Heat Project) Provide financial incentives and assistance for insulation and clean heating (The Clean Heat Project) Extensive public information and education campaigns, including advocating for voluntary curtailment on nights of high pollution and promoting energy efficiency Extensive public information and education campaigns, including advocating for voluntary curtailment on nights of high pollution and promoting energy efficiency

Main elements of the Air Plan l Control of industrial emissions l Reduction of vehicle emissions l Outdoor burning ban

Planning issues case study: possible effects of residential development on the Port Hills

Development on the Port Hills Montgomery Spur

Convergence of nocturnal airflow over Christchurch

Beckenham July 1995 (black arrow marks onset of cold air drainage from the Port Hills)

Woolston 3-4 August 2000 (switch to cold air drainage from the Port Hills started around 1800 NZST)

Conclusions l Understanding of the air pollution problem in Christchurch has improved over recent years following a decade of research conducted by various agencies l The focus is shifting towards developing management tools that can be used to protect the health of both humans and the wider environment l These tools will be increasingly applied through the RMA framework