Anvil Road artificial wetland - drainage basins
2177. Hon Alison Xamon to the Minister for Environment
I refer to the proposed Anvil Rd artificial wetland and I ask the following —
(1) What is the area of the Anvil Rd, Welshpool drainage basin?
(2) What is the area of its catchment?
(3) How many drainage basins or sumps are present in the catchment of the Swan and Canning Rivers?
(4) What approximate area of the Swan Coastal Plain is drained through drainage basins or sumps?
(5) According to the 2007 Environmental Protection Authority publication, ‘the State of the Environment’, 80 percent of wetlands on the Swan Coastal Plain have been lost through urban development filling, drainage, clearing and through environmentally threatening processes. How many remnant wetlands remain on the Swan Coastal Plain?
(6) What active on-ground actions is the State Government doing to maintain ecological system health, biological diversity and hydrological integrity of conservation category, resource enhancement category and multiple use wetlands on the Swan Coastal Plain?
(7) The Swan Canning Water Quality Improvement Plan (WQIP) has a budget of $3.2 million. This Swan Canning WQIP covers the entire Swan Coastal Plain, foothills and hinterland. The Department of Environment and Conservation (DEC) and Swan River Trust (SRT) plan to spend an amount equivalent nearly half that budget on one nutrient stripping basin. How much would it therefore cost to apply the same intervention tactics intended to be used at Anvil Rd drainage basin to every single drainage basin and sump across the entire Swan Canning catchment?
(8) Within DEC and SRT, what staffing and technical resources are dedicated to long-term monitoring,
compliance and cost-recovery actions within the Swan Canning catchment in response to high nutrient,
heavy metal and organicide pollution from either background or point sources?
(9) How many pollution prevention notices, particularly relating to illegal and/or unlicensed discharge to drains, watercourses or groundwater, have been issued by DEC/SRT in response to pollution in the Swan/Canning catchment for the years —
(a) 2005-6;
(b) 2006-7;
(c) 2007-8;
(d) 2008-9; and
(e) 2009-10 to 25 March 2010?
(10) How many pollution prevention notices, particularly relating to illegal discharge to drains, watercourses or groundwater, have been issued by DEC/SRT in response to pollution in the catchment of the Anvil Rd drainage basin for the years —
(a) 2005-6;
(b) 2006-7;
(c) 2007-8;
(d) 2008-9; and
(e) 2009-10 to 25 March 2010?
(11) How many prosecutions have been commenced under sections 49, 50, 50A and /or 50B of the Environmental Protection Act 1986, have been commenced by DEC/SRT in response to pollution in the Swan/Canning catchment for the years —
(a) 2005-6;
(b) 2006-7;
(c) 2007-8;
(d) 2008-9; and
(e) 2009-10 to 25 March 2010?
(12) How many pollution monitoring stations are located upstream in the catchment of the Anvil Rd drainage basin?
(13) What has been the monitoring trend regarding the detected levels of nutrients, heavy metals and organicides within surface water, groundwater and soils within the Anvil Rd drainage basin over the period of 2005 to 2010?
(14) What are the expected contaminants to be found in the Anvil Rd drainage basin sediments in —
(a) what forms;
(b) volumes; and
(c) concentrations?
(15) How is it proposed that these contaminated sediments will be transported to an appropriate waste control facility?
(16) Have additional costs for contaminated wastes been included in the estimate of costs for the project?
(17) If yes to (16), what are the specific excavation, transfer, transport and containment costs for the contaminated waste sediment?
(18) What are the likely sources of contaminants in the drainage catchment and groundwater leading to the Anvil Rd drainage basin?
(19) What education and awareness campaigns are being specifically targeted at industrial, residential and commercial property owners and tenants within the catchment of the Anvil Rd drainage basin?
(20) What are the likely and desired educational and awareness outcomes from such campaigns?
(21) What are the likely and desired environmental outcomes from such campaigns?
(22) Have any additional funds been sought from industrial, residential and commercial property owners and tenants upstream of the Anvil Rd drainage basin in order to fund engineering works and ongoing monitoring and compliance?
(23) What is the intended reduction in nutrient, heavy metals and organicide concentrations between receiving water and discharge into the drainage channel and therefore back into the Canning River?
(24) What is the intended reduction in nutrient, heavy metals and organicide concentrations between receiving water and discharge water into the superficial aquifer and therefore into deeper aquifers?
(25) What is the engineering lifespan of the artificial wetland before needing extensive reengineering?
(26) What is the expected buffering capacity of soils and flora plantings in the Anvil Rd drainage basin particularly to maintain expected reductions in nutrients, heavy metals and organicides over the next —
(a) ten years; and
(b) twenty years?
(27) What is the operational lifespan of the artificial wetland?
(28) How often will the Anvil Rd drainage basin be dredged to remove detained nutrients, heavy metals and organicides over the next twenty years?
(29) Which decision making agency will be responsible for ongoing maintenance of the Anvil Rd drainage basin?
(30) Are they sufficiently funded and indexed over the long-term to ensure intended pollution mitigation over the expected operational lifespan of the artificial wetland?
(31) Are all residential, commercial and industrial properties within the catchment of the Anvil Rd drainage basin completely and operationally connected to the Water Corporation deep sewerage system?
(32) If no to (31), is the Minister for the Environment coordinating with the Minister for Water, to ensure that groundwater and surface water contamination from septic tanks, and leach drains in the Anvil Rd drainage basin catchment will be limited in the short term?
(33) If no to (32), what is the desired timetable for the Department of Environment and Conservation to ensure sewerage connections within the Anvil Rd drainage basin catchment are made to all residential, commercial and industrial properties, and thus remove a major continuing source of groundwater and surface water contamination?
Hon DONNA FARAGHER replied:
(1) The Anvil Way basin is currently approximately 8000m², however works at the site will see the basin area expanded to approximately 9000m².
(2) The entire Mills Street main drain catchment is approximately 12km². The Anvil Way compensation basin is located in the middle of this catchment therefore approximately 6km² could be considered the catchment area of the Anvil Way Basin.
(3) There is currently no record of the number of drainage basins or sumps in the Swan Canning catchment. A GIS database has been developed as part of the Western Australian Land Information Service to bring together all the stormwater network data in a standardised format, however this database does not contain a complete dataset and is unlikely to in the foreseeable future.
(4) The area of the Swan Coastal Plain that flows into the Swan Canning River System is approximately 2126km² and there is no record of the area which is drained through drainage basins or sumps.
(5) The exact number of wetlands on the Swan Coastal Plain has not been established because of the complexity of identifying wetland boundaries and types. The Department of Environment and Conservation's (DEC) Geomorphic Wetlands Swan Coastal Plain dataset indicates that 70 per cent of wetland areas mapped on the Swan Coastal Plain have been highly disturbed. Approximately 20 per cent of the area of wetlands remaining are in a relatively undisturbed condition and retain high ecological values and are assigned a management category of Conservation.
(6) On-ground actions vary according to wetland tenure and ownership, values, threats, and status under both State and Commonwealth legislation. On-ground actions for wetlands on lands managed by DEC include feral animal and weed control, fire management, rehabilitation, fencing and visitor access management, with particular focus on wetlands listed under the Ramsar Convention and those
containing habitat for threatened species and threatened ecological communities. Advice, assistance and incentives for protection of wetlands outside DEC-managed lands are variously provided through the Urban Nature, Healthy Wetland Habitats, Land for Wildlife and nature conservation covenanting programs. Funding is available under the Government's Environmental Community Grants program for wetland conservation projects across public and privately owned wetlands, and natural resource management groups and programs supported by the Government also deliver wetland conservation actions.
(7) The Swan Canning Water Quality Improvement Plan does not cover the entire swan coastal plain, only the Swan Canning catchment. It would not be appropriate to replicate the intervention techniques being used at the Anvil Way basin to all drainage basins and sumps in the Swan Canning catchment. The Anvil Way basin is located in the Mills Street main drain catchment that is known to be contributing contaminants and some of the highest nutrient loads to Canning River.
(8) Within the Swan River Trust approximately $800,000 is dedicated for long-term water quality monitoring of the Swan and Canning rivers and its priority catchments to assess compliance against targets for a healthy river system. The monitoring program is predominantly focussed on nutrients from background sources, but also includes investigating priorities identified in the three year non-nutrient contaminants program that was completed last year. The monitoring program informs the delivery of the Trust's five year, $40 million Healthy Rivers Program, which is complemented by the Swan Canning Water Quality Improvement Plan. At the Trust 22 staff work on the delivery of the Healthy Rivers Program.
The Swan Canning catchment is generally within the Department of Environment and Conservation's (DEC) Swan Region which has an industry regulation team of 22 staff responsible for regulating industry emissions and discharges and responding to pollution complaints. The team is supported by the DEC Pollution Response and Environmental Enforcement Units, which operate statewide and comprise 6 and 16 staff respectively. In addition local government authorities are able to use the Environmental Protection (Unauthorised Discharge) Regulations 2004 for minor pollution incidents.
(9) DEC has a number of enforcement tools available for unauthorised discharges to the environment. This
includes prevention notices under Section 73A of the Environmental Protection Act 1986,
infringements notices under the Environmental Protection (Unauthorised Discharge) Regulations 2004,
Environmental Field Notices and Letters of Warning.
(a) 2005-06
• 1 Environmental Field Notice — Liquid Waste
• 2 Environmental Field Notices — Hazardous Material
(b) 2006-07
• 6 Environmental Field Notices — Unauthorised Discharge Regulations
• 4 Environmental Field Notices — Liquid WasteExtract from Hansard
• 1 Environmental Field Notice — Hazardous Material
• 1 Infringement — Liquid Waste
(c) 2007-08
• 10 Environmental Field Notices — Unauthorized Discharge Regulations
• 1 Environmental Field Notice — Liquid Waste
• 1 Infringement — Unauthorised Discharge Regulations
• 1 Letter of Warning — Liquid Waste
(d) 2008-09
• 9 Environmental Field Notices — Unauthorized Discharge Regulations
• 4 Environmental Field Notices — Liquid Waste
• 2 Environmental Field Notices — Hazardous Material
• 2 Infringements — Unauthorised Discharge Regulations
• 1 Infringement — Liquid Waste
(e) 2009-10 to 25 March 2010
• 3 Environmental Field Notices — Unauthorized Discharge Regulations
• 5 Environmental Field Notices — Liquid Waste
• 2 Environmental Field Notices — Hazardous Waste
• 1 Infringement — Hazardous Waste
• 1 Prosecutions Brief — Unauthorised Discharge Regulations
(10)
(a) 2005-06 1 Environmental Field Notice — Hazardous Material
(b) 2006-07 1 Environmental Field Notice — Liquid Waste
(c) 2007-08 1 Environmental Field Notice — Unauthorised Discharge Regulations
(d) 2008-09 — None
(e) 2009-10 to March 2010 — None
(11)
(a) 2005-2006
• 1x $25,000 Modified Penalty Fine (section 50B EP Act)
• 2 x $12,500 (total $25,000) Modified Penalty Fines (section 49 EP Act)
(b) 2006-2007 — None
(c) 2007-2008
1 x prosecution (section 3(1) Unauthorised Discharge regulations)
(d) 2008-2009
1 x prosecution — Licence Contravention (section 6(4) Controlled Waste regulations)
(e) 2009-10 to 25 March 2010
2 x pending prosecutions 2010 involving:
Section 3(1) Unauthorised Discharge regulations x 9 charges
Section 3(1) Unauthorised Discharge regulations x 8 charges
Section 11(1) Controlled Waste regulations x 11 charges
Section 25(1) Controlled Waste regulations x 12 charges
(12) There are 35 monitoring sites located upstream of the Anvil Way basin.
(13) Surface water has regularly been monitored for nutrient and heavy metal concentrations over the period 2005-2010. Nutrient concentrations in the basin showed no consistent trend over this period, other than being mostly elevated when compared to Healthy Rivers Program long term targets of 1mg/L for total nitrogen and 0.1mg/L for total phosphorus. Heavy metal concentrations in surface water have also shown no consistent trend over the period 2005-2010, other than aluminium, copper and zinc concentrations above ANZECC (2000) 95% protection trigger values for fresh water ecosystems. Cadmium, nickel and lead also occasionally showed concentrations which exceed ANZECC (2000)
trigger values. Concentrations of other heavy metals have been recorded but results cannot readily be compared to guideline values.
Groundwater monitoring around the Anvil Way basin has just commenced as part of the project and therefore no data is available as yet.
Sediment nutrient samples have been collected annually from 2005-2009 (excluding 2006) with combined results for the basin showing no statistically significant trends.
Sediment heavy metal results have not consistently been collected however results from 2005 and 2009 show heavy metal concentration which appear to have increased but not in a statistically significant sense. 2009 results are summarised in Question (14c).
There is not enough data or comparable guidelines to draw conclusions in regard to concentrations of other contaminants.
(14)
(a) Long chain petroleum hydrocarbons and metals (Aluminium, Arsenic, Cadmium, Copper, Chromium, Iron, Lead, Mercury, Nickel and Zinc). Potential acidity is also an issue as some of the sludge and sediment will generate acid if allowed to oxidise without neutralising treatment.
(b) Investigations indicate that approximately 1400m³ of sludge and sediment is present in the basin
(c) Sludge and sediment sampling at the Anvil Way compensation basin has been undertaken in 2009. I table the attached sediment data set. [See paper 2040.]
(15) After removal from the basin, treatment to prevent acid production and drying in a lined containment area on site, stockpiled material will be sampled and analysed to determine leachable concentrations of the contaminants of concern. Leachable concentration and concentration limit values for waste classification from DEC's Landfill Waste Classification and Waste Definitions 1996 (as amended) will then be used to determine appropriate disposal. The material will then be trucked to the appropriate landfill facility ensuring that all health and safety requirements are met.
(16) Cost estimates have been guided by results from site investigations and include treatment, storage and disposal of the contaminated sediment and sludge.
(17) Approximately $960,000 (excluding GST).
(18) Surrounding land uses are predominantly industrial and it is likely that many of the contaminants originated from these premises. Some of the contaminants are also typical of road runoff in urban areas.
(19) The Perth Region NRM is delivering the Light Industry Audit and Education Program across the Perth metropolitan area. In December 2009, I announced $250,000 for the continuation of this program which will target light industry precincts in the Swan Canning Catchment, focusing on the Mills St main drain catchment around the Anvil Way basin.
(20) Previous educational and awareness campaigns through Perth Region NRM's Light Industry Audit and Education Program have shown that prior to audits being conducted up to 33% of businesses were noncompliant with environmental legislation such as the under the Environmental Protection (Unauthorised Discharges) Regulations 2004 and that this dropped to less than 2% following an audit combined with educational material and tailored assistance. Previous industry surveys, not audits, in partnership with Edith Cowan University's 'Small and Medium Size Enterprise Research Centre' have shown that before any form of intervention, 62% of businesses were unable to correctly answer where stormwater flowed to. (Bellevue Sustainable Industry Project, August 2007).
(21) Perth Region NRM through their auditing and survey projects have found that a high percentage of businesses do not properly treat or process industrial wastewater prior to disposal. For example, research in the Bellevue area showed that 48% of businesses did not treat wastewater prior to disposal, whereas surveys undertaken within the Cities of Gosnells and Cockburn this figure decreased to
around 27%. This type of program can significantly improve levels of awareness as to how and why wastewater must be properly treated and disposed of. Combined with specific assistance tailored to each businesses' needs, and information on relevant legislation, the level of non-compliance with regard to liquid waste disposal can be considerably reduced.
(22) As the contamination cannot be attributable to any one event, business or individual, no funding from industrial, residential and commercial property owners and tenants has been sought. Where there is evidence linking discharges to companies or individuals, the Local Government Authority can enforce the Unauthorised Discharge Regulations and the DEC can require the offender to monitor, clean up and rehabilitate the site where there is an adverse effect on the environment.
(23)-(24) Estimations of contaminant reductions for the system have not yet been undertaken, however the treatment system will reduce particulate and soluble contaminants in the drainage system through natural processes. Trust officers plan to undertake surface water analysis prior to construction so that estimated performance can be compared against actual monitoring data.
(25) The limitations to the lifespan of the project result from the impacts from erosion, sedimentation and degradation of hydraulic structures. The Anvil Way Project has been designed such that sediment can be periodically removed from a designated area in the basin and structures have been designed to resist erosion. Regular maintenance will be undertaken as a part of the project which will also ensure system longevity. Hydraulic structures have a life span of around 80 years and can be replaced as needed. Essentially, so long as the system is regularly maintained and there are no major changes to catchment landuse and resultant water quality then the life of the current treatment system could be considered to be at least 80 years.
(26) A specific buffering capacity figure cannot be provided for soils and flora. The expectation is that the majority of vegetation within the compensation basin will reach its peak density after approximately five years. Regular monitoring planned to be undertaken on the treatment system will provide information on the buffering capacity of the system.
(27) Please see the response to Question 25.
(28) A sedimentation area has been included in the design of the basin and is not expected to be dredged during the life of the project. The sediment area will regularly accumulate sediment and this will be tested and disposed of to the appropriate class of landfill as a part of scheduled maintenance activities.
(29) Several decision making agencies are responsible for maintenance of the Anvil Way Project, each of these agencies is a project partner (including Swan River Trust, City of Canning and Water Corporation. The South East Regional Centre for Urban Landcare (SERCUL) is also a project partner but not a decision making authority). All project partners have been involved in the planning, design
and approval process with a maintenance plan currently being finalised which will identify roles and responsibilities. The Swan River Trust's role is that of coordination, funding capital works and short term maintenance (approximately 3 years). Following this period, agreements will be in place that will ensure that the City of Canning and Water Corporation will continue to maintain the site.
(30) The City of Canning and Water Corporation have entered into agreements to continue to maintain the site.
(31) As a part of the modelling for the Swan Canning Water Quality Improvement Plan (SCWQIP) it has been identified that a portion of the Mills Street main drain catchment is still not connected to deep sewerage.
(32)-(33)I refer the Member to the Minister for Water on matters regarding deep sewerage.