| STORMWATER TREATMENT FACILITY - CUDGEN CREEK, KINGSCLIFF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| A project funded under the
Coast and Clean Seas Clean Seas
Program of Environment Australia
Contents
List of Appendices
Final Report Cudgen Creek, in north-east New South Wales, is a small waterway that runs adjacent to the coastal urban centre of Kingscliff in Tweed Shire. This estuary, and the adjacent beach, are the focus for recreation and tourism in the region. The Estuary Management Plan recently completed for Cudgen Creek by Tweed Shire Council identified a major community concern about stormwater pollution of the estuary and beach. There are no stormwater outfalls directly onto the beach, however, two significant stormwater outfalls near the mouth of Cudgen Creek drain most of the Kingscliff CBD and adjacent residential area into Cudgen Creek. A grant of $85 000 through the Coast and Clean Seas, Clean Seas Program of Environment Australia enabled the installation of two Continuous Deflective Separation (CDS) Units (stormwater treatment facilities) upstream of these two stormwater outfalls. One of the key objectives of the Project was to install state-of-the-art treatment facilities on stormwater lines draining to Cudgen Creek estuary to reduce overall marine pollution from land based inputs. The second key objective was to use monitoring and analyses of the trapped litter to provide information on the efficacy of the Units and contribute toward stormwater awareness in Tweed Shire. The Project successfully met the objectives, with an estimated reduction of 2.4 tonnes of sediment, organics, plastics and other litter reaching Cudgen Creek and the Pacific Ocean each year from this small, coastal catchment. Kingscliff High School students became involved in the monitoring and analysis of trap data and the production of display materials. This gave invaluable experience and awareness for those students and provided "real" information to the community on the extent of local stormwater pollution. A Stormwater Awareness Campaign Survey found that the greatest retention of information by the community came from a combination of media advertising and editorial, particularly television. The information collected to date will be used to further fine tune the ongoing Stormwater Awareness Campaign of Tweed Shire Council and assist with the selection of appropriate technology for stormwater treatment devices in other areas. Cudgen Creek, in north-east New South Wales, is a small waterway that runs adjacent to the coastal urban centre of Kingscliff in Tweed Shire. This is a popular holiday destination for many families who come to enjoy the beach and estuary. That enjoyment had been marred in later years by the litter and debris that could be found stranded on the beach and floating in the estuary.
Tweed Shire Council recently completed an Estuary Management Plan for Cudgen Creek. One of the outcomes of community consultation for this Plan was that stormwater was seen as a major problem for this otherwise healthy creek. Cigarette butts, assorted litter associated with urban life, paint slicks, algal blooms - could all be attributed to stormwater. Two stormwater outfalls near the mouth of Cudgen Creek drain most of the Kingscliff CBD and adjacent residential area into this waterway. From there it is washed into the ocean with the twice daily tides. This stormwater system drains an area that includes a primary school, residences, shops (including several food outlets), roadways and a popular park. The first outfall is located near a boatramp. It is a popular swimming and recreational area and has been identified as the most significant single outlet discharging into Cudgen Creek. The second outfall is located within another foreshore park, also a popular swimming and recreation area. This outfall is close to Kingscliff High School, the students and teachers of this school being highly active in local environmental issues. Kingscliff High School became involved with the monitoring and education campaign associated with this Project. This Project enabled the installation of a Continuous Deflective Separation (CDS) pollution control trap on both the stormwater outfalls near the mouth of Cudgen Creek. These CDS Units greatly reduce the amount of sediment (which causes problems for seagrass and other marine vegetation as well carrying excess nutrients to the sea), organic material (which reduces available oxygen for marine creatures as well as introducing excess nutrients) and litter (no need to elaborate on the devastation of plastics to our marine environment) in stormwater. The selection of CDS Units is clearly justified by the superior results achieved by this technology. The results from the two clean-outs to date have shown large percentages of sediments and fine silts are captured along with the gross litter, grass clippings and leaf litter. This represents literally TONNES less pollutants going into Cudgen Creek and the ocean.
2. Location of the two CDS Units at Kingscliff, NSW Two CDS Units were placed on stormwater lines running through Faulks Park and Jack Julius Park, Kingscliff. The outfalls of these two lines are discharging near the mouth of Cudgen Creek. The catchment sizes of these stormwater outfalls is 7.4 ha and 16 ha respectively. Figure 2 illustrates the location of the two CDS units. The Aim of the Project is to improve local estuarine and coastal environmental conditions by reducing stormwater pollution entering Cudgen Creek. This includes educating the community on strategies to reduce land-based sources of marine pollution. The key Objectives of the Project were the:
The Project has successfully met these objectives as outlined in Section 5, Project Outputs and Outcomes. More information on the results of the trapped litter analysis and the Stormwater Awareness Campaign is detailed in Sections 6 and 7.
CDS Technologies designed and installed the two 1.5 metre CDS Units. The size and location of the units were determined by the catchment size and invert gradient of the stormwater lines. Following detailed site design, the Units were manufactured and transported to site in several pre-fabricated pieces. Excavation and installation to commissioning was approximately 2 weeks for the Faulks Park Unit. The second Unit required relocation when excavation uncovered a basalt layer that could not be penetrated. The Unit was moved further up the stormwater line with new excavations costing several days of the project. The Units were cleaned six weeks after commissioning using a small crane to lift the clean-out basket from the Unit, placing the litter on a large tarp for sorting and weighing. A second clean-out was conducted six weeks later. The contents of the clean-out baskets were spread on to a large tarp. Council officers did an initial sort to ensure that there were no sharps or other potentially dangerous items. The students then sifted through the contents separating the plastic and other litter items. The sediments and organic materials were weighed together due to the difficulty in separating these components. A sediment sample was removed for drying and grain size analysis at the Tweed Shire Council Soil Laboratory. The full results of these sediment analyses are included as Appendix E. The information collected from the clean-out events, as well as the events themselves, were used as the basis for displays and media releases within the context of the Stormwater Awareness Campaign of Tweed Shire (See Appendices). Local television and print media were targeted with advertising and editorial content. This was supplemented with the distribution of other promotional material such as stickers, fridge magnets and information leaflets.
5. Project Outputs and Outcomes The major outputs of the Project and their associated outcomes are detailed below.
The CDS Units had been installed for six weeks prior to the first cleaning and litter analysis on the 13th of October 1998. Both units were cleaned and the contents sorted into a number of categories. Sediment analysis was done on a sample from each trap. The second clean out was undertaken on the 24th of November 1998, six weeks after the first. The results for both traps are listed in Table 1. Nine Kingscliff High School students, members of the Only Rain Down the Drain Committee (ORDDAC), sorted and weighed the entire contents of both traps on these two occasions. The contents of the clean-out baskets were spread on to a large tarp. The students sifted through the contents separating the plastic and other litter items. The sediments and organic materials were weighed together due to the difficulty in separating these components. A sediment sample was removed for drying and grain size analysis at the Tweed Shire Council Soil Laboratory. The full results of these sediment analyses are included as Appendix E. Table 1: Trap contents for Faulks Park and Jack Julius Park CDS Units on 13 October and 24 November 1998.
Analysis of the contents of each unit allows some comparisons to be made between the two adjacent catchments. It is proposed to analyse at least two further sets of captured material for comparisons between seasons and to gain a better understanding of the capacity and efficiency of the CDS units. Sediment analysis from the first clean out found grain sizes down to less than 0.075 mm had been trapped (and up to small brick size!). The sediment trapped in the Jack Julius Park Unit consisted of a greater percentage of larger grain size than the Faulks Park Unit. A significant source of gravel material is obviously located within the catchment and is to be investigated. The analyses showed that grass clippings, leaf litter and sediments comprised by far the greatest contribution to the trapped litter. Further breakdown and analysis of the litter coming from each catchment enables specific sources of pollution to be targeted. This information will be used to fine tune the ongoing Stormwater Awareness Campaign of Council. For example, the Jack Julius Park unit contained an obviously higher amount of grass clippings. The gardeners within this catchment will be targeted for a specific campaign to reduce this input into the stormwater. Another trend was the high number of tennis balls at this site - not surprising considering the local tennis club is just up the road. 7. Stormwater Awareness Campaign A Stormwater Awareness Campaign was launched in Tweed Shire in March 1998. A variety of methods are being used to disseminate information on stormwater issues to the Tweed Community. The reporting of real data and information to the community is seen as one of the most effective methods of reaching the widest range of people. The use of each clean out and other stormwater management events, such as publicity of grants received and construction of facilities, raises the overall awareness of stormwater issues much more effectively than general information. This is illustrated by the results from the community survey.
Before Campaign Survey In September 1997, 170 Tweed residents were selected randomly from the telephone directory and asked a series of questions relating to environmental issues in the Tweed. The topics included phosphorous awareness, recycling, river management, bait bags, stormwater and water conservation. A huge 45% of those surveyed said that they were NOT aware that stormwater runs into our waterways untreated. This result compares fairly poorly with the 1997 NSW EPA community survey which showed that 81% of respondents were aware that stormwater drains run directly into waterways. However, this would not be directly comparable as the questions were worded differently. After Campaign Survey Preliminary results of the after campaign telephone survey undertaken in July and August 1998, several months after the media "blitz", show a large increase in public awareness of stormwater issues. Questions included general awareness of stormwater, whether people had recently seen material on stormwater, whether people knew of specific practices which could be adopted to improve water quality and whether individual’s practices have changed. The high level of awareness of the actual campaign is illustrated in Figure 3, along with a small increase in the knowledge that stormwater is not treated. Unfortunately, one of the easiest actions for the community to adopt, washing the car on the lawn or at a car wash, does not seem to have increased within the scope of this survey.
The general awareness of stormwater had increased from the earlier survey, with 70% of respondents indicating that stormwater was not treated. However, 21% of respondents still did not know what happens to stormwater. The effectiveness of the campaign could be seen in the large percentage of respondents who remembered media coverage about stormwater several months later. The television exposure was particularly effective, with 39% of respondents recalling the advertisement and 23% recalling television news editorial. A total of 11% of respondents recalled the newspaper coverage, and 7% recalled the articles in Council’s newsletter "Tweed Link". It can be seen that television was by far the most successful medium for communicating the message! The message from the campaign logo was considered highly successful, with a huge 75% of respondents indicating that "Please...Only Rain Down the Drain" relates to rubbish.
Figure 4 illustrates that television advertising and editorial had the greatest impact on the general public. The response to changing individual practices to improve stormwater quality was good, with a large 84% of respondents able to indicate how they had changed their individual practices in the past two years. However, 40% of respondents indicated that they still washed their cars on the footpath, road or driveway, so there is still much scope for improvement. The stormwater treatment facility data collected from this Project and others around the Shire will feed into this ongoing Stormwater Awareness Campaign and assist in fine tuning the methods used and information disseminated to the community. A breakdown of the Project expenditure is summarised in Table 2. Additional costs were incurred from the original project proposal by the inclusion of "clean-out baskets" for the units. These assist with maintenance and analysis of capture rate data. This was an additional cost to Council of $6 000. A delay in installation of the second Unit in Jack Julius Park was the result of difficult ground conditions. These required the relocation of the Unit further up the stormwater line than designed. This delay created some additional costs to Council. In retrospect, a geotechnical report is considered essential prior to installing large subterranean units such as the CDS which require substantial excavations. Table 2: Total expenditure on the Kingscliff Stormwater Treatment Facilities Project.
*Kingscliff High School students (Only Rain Down the Drain Action Committee) contributed in kind support through analysis of trapped litter and assistance with display for Water Week 1998. To further the outcomes of this Project and gain maximum community awareness it is proposed to undertake the following activities as part of Council’s ongoing Stormwater Management Program:
APPENDIX A
ORDDAC Report by Olivia Miles and Tyrone Carr, Kingscliff High School The reason why we joined the Only Rain Down the Drain Action Committee (ORDDAC) is because it would be a great learning experience for us to learn about how much rubbish gets put down our local stormwater drains. Yesterday 13.10,98 was a great learning experience for every one of us who participated. Most of the people who participated yesterday entered a competition to design a poster about the CDS Units and stormwater drains. Then two of the Year 9 students attended an EPA (Environment Protection Authority) meeting at Tweed Heads Bowls Club earlier in the year. By this experience we can teach other people and students in our committee what we did. As you can see by our display we found chip wrappers, aluminium cans, leaf litter cigarette butts and fast food rubbish. We were appalled with our discovery of how much rubbish we found and hope in the near future that we can help others understand the effects of people dumping rubbish carelessly, with no thought what so ever.
APPENDIX
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