Environment Protection Authority v Lake Macquarie City Council

[1999] NSWLEC 4

Land and Environment Court

of New South Wales

CITATION:	Environment Protection Authority - V - Lake Macquarie City Council [1999] NSWLEC 4
PARTIES	Prosecutor Environment Protection Authority
Defendant Lake Macquarie City Council
NUMBER:	50101 of 1998
CORAM:	Lloyd J
KEY ISSUES:	:- Environmental protection Offences and penalties
LEGISLATION CITED:	Environmental protection Offences and penalties
DATES OF HEARING:	12/10/1998; 12/11/1998; 12/18/1998
DATE OF JUDGMENT DELIVERY:	02/04/1999
LEGAL REPRESENTATIVES:	Prosecutor J C Kelly Defendant M H Tobias QC

JUDGMENT:

1. The defendant pleads guilty to a charge that on or about 7 August 1997 at Awaba, it committed an offence against the Environmental Offences & Penalties Act 1989 in that it did pollute waters contrary to s 16(1) of the Clean Waters Act 1970.

2. The relevant facts relating to the commission of the offence and the steps subsequently taken to remedy the cause, which are now described, are derived from a Statement of Agreed Facts tendered by consent and from the affidavits, oral evidence and other material relied upon by the parties.

The Awaba Tip

3. The defendant is and was at all material times the occupier and operator of the Awaba Waste Disposal Facility (known as the “Awaba Tip”) at Wilton Road, Awaba. The tip is located on Crown land known as Lot 372 in Deposited Plan 723259. Land uses within an approximate one to two kilometre radius of the tip include: the Awaba State Coal Mine, a private haulage road, the Toronto Country Club, a motor club, a golf course, the township of Awaba, the Leisure Life Caravan Park, the Toronto Seventh Day Adventist School and St Joseph’s Church and Primary School.

4. The Awaba Tip is approximately 30 hectares in area, with approximately 20 hectares devoted to the actual emplacement of waste and supporting infrastructure. The tip currently receives approximately 143,000 tonnes of waste per year. The tip is planned to operate until 2010 and the life span of the tip could be extended for several years beyond this.

5. An unnamed creek travels through the southern portion of the tip site. For convenience it has been referred to in this proceeding as the “Wilton Road Creek”. This creek is within 40 metres of the landfill emplacement area. For this reason, the Awaba Tip is considered to be sited within an “environmentally sensitive and inappropriate area” as defined in the Waste Minimisation and Management Regulation 1996 and by the Department of Urban Affairs and Planning.

6. The Wilton Road Creek flows eastward into Lake Macquarie at Kilaben Bay, approximately 2 kilometres away. There is a fall in the land from the base of the landfill emplacement area to Wilton Road Creek. Approximately 60 metres to the south of the southern boundary of the tip, the Wilton Road Creek joins with another unnamed creek and it is the joined creek which flows into Kilaben Bay.

7. The Awaba Tip is the defendant’s only operating landfill. Development consent for the tip was granted by the defendant to itself on 8 October 1986. Conditions of the development consent include the following:

(a) downsite surface water and groundwater quality to be monitored and irrigation areas to be located as recommended by the Water Resources Commission and the State Pollution Control Commission;

(b) development proceeding in compliance with the conditions set by the NSW Department of Health, including

(i) suitable surface and sub-surface drains to be provided and maintained to divert all upland seepage and surface water clear of the tipping area prior to the commencement and during tipping operations;

(ii) all depot-rubbish deposited on the Depot to be covered with at least 150 mm of soil or other suitable material on completion of each day’s tipping;

(iii) daily inspections of the site shall be made to ensure that the conditions of consent are being observed.

8. An environmental impact statement was prepared for the Awaba Tip called “Environmental Report for Solid Waste Disposal Depot, Wilton Road, Awaba” by Mitchell McCotter & Associates in August 1985. According to that document, the following measures had been designed to ensure that surface and groundwaters downstream of the tip were not polluted:

(a) clean water diversion drains will be constructed upstream of any disturbed areas. They will be formed as broad shallow open channels running on contour around the proposed waste emplacement area. Channel gradients will be kept low to avoid problems of scour, and inverts and sideslopes in weathered materials will be topsoiled and stabilised with appropriate grasses;

(b) diversion drains will be fully constructed prior to the commencement of waste emplacement, and will be progressively relocated as required during the life of the depot;

(c) drains will be designed to carry without over-topping at least a one in ten year return period storm of critical duration for the particular sub-catchment;

(d) to avoid run-off from unrehabilitated covered areas, which will become contaminated with sediment, from entering water courses and deteriorating the water quality in Lake Macquarie, all such run-off will be directed to sedimentation ponds;

(e) the sedimentation ponds have been designed to fully contain run-off from a two hour one in ten year return period storm. They will have an individual capacity of 2 Ml. The pond walls will be constructed in accordance with proper engineering practice and the spillways will be designed to safely pass run-off from a 1 in 100 year storm;

(f) minimisation of the production of leachate is to be achieved by careful waste compaction and covering and the isolation of successive layers of waste;

(g) all leachate will be collected for treatment;

(h) surface run-off from the fill face and any area where water could come into contact with wastes will also be directed to the contaminated run-off treatment pond. Such run-off will usually contain high concentrates of suspended solids, and can additionally contain bacteria which affect human health.

9. Until the commencement of the Waste Minimisation and Management Act 1995 the prosecutor did not regulate the Awaba Tip. The requirement for the tip to be licensed under this Act commenced on 1 July 1997. Prior to the commencement of the Act, the defendant and the Department of Health were the sole regulators of the Awaba Tip in relation to any necessary consents and approvals.

10. The defendant applied for a licence under the Waste Minimisation & Management Act on 16 May 1997. The prosecutor granted licence No 005873 to the defendant on 13 October 1997. The conditions of the licence included:

(a) the defendant must not pollute waters except as expressly permitted by the licence;

(b) the defendant must prepare and submit to the prosecutor a landfill environmental management plan by 31 December 1997.

The licence does not expressly permit pollution of waters. I note that the defendant duly prepared and submitted to the prosecutor a landfill environmental management plan prior to 31 December 1997 as required. A further licence was issued by the prosecutor under the Act on 13 October 1998.

11. The defendant did not at the time of the offence and does not at present have a licence under the Pollution Control Act 1972 permitting the pollution of waters.

12. As I have said, the defendant had submitted a landfill environmental management plan to the prosecutor by 31 December 1997. According to that document,

“Poor management of surface water may result in erosion of the landfill and surrounding landform, causing sediment build-up in stormwater and leachate collection ponds and the further possibility of ‘waste wash out’ where underlying waste is exposed due to erosion of the cover material. Permeation of surface water into the landfill may also result in excessive leachate generation and flooding and water-logging of operational areas.”

The document enumerates the design objectives of the site to minimise surface water contamination as follows:

(a) provide structures such as berms and drainage lines that help to minimise soil erosion during operation of the facility;

(b) provide stormwater detention ponds (ie sedimentation ponds) of sufficient volume to collect sediment before it enters the natural environment; and

(c) to divert off-site water away from the landfill area.

13. The landfill environmental management plan also sets out control measures which should be in place to ensure the prevention of flooding and erosion of the landfill mass and surrounding landform and the proper operation of leachate and stormwater detention ponds (ie sedimentation ponds) including the following:

(a) removal of accumulated sediment from all detention ponds;

(b) inspection and, where necessary, repair of stormwater drains, drainage lines, sediment traps and ponds;

(c) regular removal of litter, debris and excess plant and algal growth from drainage channels and sediment ponds;

(d) the extent of exposed or cleared land should be kept to a minimum where possible and all top soil should be set aside for re-vegetation;

(e) all completed areas of the landfill should be re-vegetated; and

(f) exposed areas should be stabilised to prevent soil erosion.

14. The Awaba Tip is classed as a solid waste class 1 landfill under the “Environmental Guidelines: Solid Waste Landfills” published by the prosecutor in January 1996. It can receive all kinds of inert waste and solid waste, including putrescible waste and other wastes approved by the prosecutor. According to surveys conducted by the defendant in 1996 and 1997, the tip receives domestic household waste, commercial waste, industrial waste, Council waste and building and demolition waste. This includes food wastes and disposable nappies.

15. The stormwater and leachate control systems at the Awaba Tip should generally operate in the following manner. Stormwater that falls outside the landfill is directed around the site via berms and drainage lines and then into sedimentation ponds on the site. The aim of the sedimentation ponds is to slow run-off so that sediment can settle out and overflows can pass through either an outlet or spillway into the natural water system.

17. All water that percolates through the landfill, namely leachate, is directed into leachate ponds and recirculated by spray irrigation over designated irrigation areas. The irrigation areas should be filled or completed areas of the landfill which have been re-vegetated. A pump is used to pump the leachate to the sprinklers for spray irrigation.

18. On 7 August 1997 there were three designated sedimentation ponds and one designated leachate pond at the tip.

19. Periodic monitoring of the leachate pond occurred at the Awaba Tip from 24 October 1991 to 25 November 1996 and of the sedimentation ponds from 2 March 1995 to 25 November 1996. No monitoring of leachate or sedimentation ponds occurred between 25 November 1996 and 7 August 1997. No monitoring of groundwater was undertaken at the Awaba Tip prior to 13 October 1998.

The incident

20. On 7 August 1997 an officer of the prosecutor, Ms M A Bruce, inspected the Awaba Tip. She saw a pond (referred to in the evidence as “leachate pond A”). It was full of an ‘orangey-brown’ liquid. In front of this pond was a sprinkler that was not in operation (referred to in the evidence as “irrigation area A”). Ms Bruce then examined a leachate pond (referred to in the evidence as “leachate pond B”) and a sedimentation pond (referred to in the evidence as “sedimentation pond A”) and found that they both contained an ‘orangey-brown’, putrid smelling leachate. There was a sprinkler spraying a fine mist of liquid onto a grassed area in front of leachate pond B (referred to in the evidence as “irrigation area B”).

21. Ms Bruce then examined the Wilton Road Creek at a point east of a road culvert (referred to in the evidence as “road culvert B”) on the access road into the tip from Wilton Road. The Wilton Road Creek was ‘browney-black’ in colour, with frothy brown clumps of material and bubbles floating on the surface. It emitted a foul, putrid odour, the same as the leachate.

22. Ms Bruce and Mr A Merrett (the defendant’s employee at the tip) then walked to a sedimentation pond (referred to in the evidence as “sedimentation pond B”). The pond was breached and was discharging leachate therefrom into the Wilton Road Creek. Ms Bruce then inspected sedimentation pond B and found that it contained putrid, sulphurous smelling leachate. The smell of the leachate was so strong that Ms Bruce felt nauseous. The leachate was ‘orangey-brown’ in colour. There were bubbles rising up in the liquid, indicating that the leachate was anaerobic.

23. Sedimentation pond B was found to contain a large amount of silt. There were no defined walls to the pond on the north and east sides and the shape of the sides were irregular and built up with silt. It seems, however, that the north and east sides were the uphill sides of the pond. The liquid in the pond was virtually level with the surrounding ground to the north and the east of the pond.

24. Leachate was found to be entering the north side of sedimentation pond B along a dark brown stained pathway. The pathway originated from the base of the landfill where waste was currently being disposed of on the tip (referred to in the evidence as the “tipping face”) and travelled down until it entered sedimentation pond B. The leachate, after entering the sedimentation pond then discharged from a large breach in the western side of the sedimentation pond down a steep decline of open scrub bushland and into the Wilton Road Creek below.

25. During the course of a conversation between Ms Bruce and Mr Merrett, Mr Merrett said:

“It’s pretty bad. I know the silt should be cleaned out. I ordered a long reach excavator to clean it out about three weeks ago but they never sent it.”

Ms Bruce said:

“Yes, it’s pretty bad. How long has this been going on for?”

Mr Merrett said:

“It’s been like this since we had those 8 to 10 days of continuous heavy rain.”

26. Ms Bruce observed the Wilton Road Creek upstream of the point where the leachate entered it and saw that the upstream water was clear and that insect larvae were present.

27. The following samples were taken by Ms Bruce on 7 August 1997 and analysed by biochemical oxygen demand (BOD):

DATE OF SAMPLING


7 August 1997

7 August 1997

7 August 1997
7 August 1997

7 August 1997

SAMPLE ID


S1

S2

S3
S4

S5


SAMPLE LOCATION

Discharge point into Wilton Rd creek - at upstream edge of mixing zone
7 metres upstream of discharge point
into Wilton Rd Creek
Sedimentation Pond B
Approximately 125 metres downstream of discharge point in Wilton Rd creek at culvert under access road
Approximately 240 metres downstream of discharge point in Wilton Rd Creek (at its junction with the other unnamed creek).

BOD VALUE


18 mg/L

4 mg/L

2,200 mg/L
840 mg/L

640 mg/L


28. After taking samples from the creek Ms Bruce had a further conversation with Mr Merrett to the following effect:

Ms Bruce said: “We need to get this fixed straight away.”
Mr Merrett said: “I can’t get the equipment.”
Ms Bruce said: “I will contact Bob Taylor and advise him of what is happening here. Thanks for your time.”

Remediation undertaken by the respondent

29. At approximately 2 pm on 7 August 1997 Ms Bruce left the Awaba Tip and immediately telephoned the respondent. By approximately 4 pm on that day the discharge of leachate from sedimentation pond B had been stopped by blocking the discharge point in that pond.

30. At 7 am on 8 August 1997 the defendant carried out the following further works:

(a) a long reach excavator was brought to the site, sedimentation pond B was de-silted and the silt placed in a cell specifically constructed for this purpose adjacent to the pond;

(b) leachate remaining in sedimentation pond B was drained into the main leachate pond and treated as leachate;

(c) the newly formed bund in the breach of sedimentation pond B was compacted to prevent any further contamination of the Wilton Rd Creek;

(d) the sprinkler heads on the leachate sprays were changed to increase the disposal of leachate by irrigation;

31. The following samples were taken by the defendant from the Wilton Road Creek on 8 August 1997 and were analysed for pH, total suspended solids, BOD, COD, ammonia and oxidised nitrogen as follows:

DATE OF SAMPLING

SAMPLE ID
SAMPLING LOCATION
BOD
COD
Total Suspended Solids
PH
Ammonia
Oxidised Nitrogen

8 August 1997
D0782/087/1
Upstream
3 mg/L
25 MG/l
11 mg/L
5.9
0.21 mg of N/L
0.06 mg N/L

8 August 1997
D0782/087/2
Discharge Pt
2013mg/L
2800mg/L
96 mg/L
6.9
94.1 mg of N/L
0.03 mg N/L

8 August 1997
D0782/087/3
Downstream*
503 mg/L
740 mg/L
50 mg/L
6.8
34.6 mg of N/L
0.03 mg N/L

The downstream sample was taken in the vicinity of the prosecutor’s sample location S4. It can be immediately seen that by 8 August 1997 the BOD at that location had dropped from 840 mg/L to 503 mg/L.

32. Between 9 August 1997 and 11 August 1997 the defendant carried out the following further works:

(a) a new sedimentation pond was constructed on the western uphill side of sedimentation pond B;

(b) the western perimeter drain was cleaned and redefined so as to direct surface drainage stormwater to the new pond;

(c) a diversion bund was constructed on the tip face to direct uncontaminated surface run-off to the new pond;

(d) the perimeter of each of the new sedimentation pond and sedimentation pond B, as well as of some of the existing diversion drains, were sprayed with bitumen emulsion/seed mix to lessen the potential for erosion and to reduce the rate of any siltation into the sedimentation ponds;

(e) “sphag sorb” was placed in the Wilton Road Creek to absorb contaminants from the soil;

(f) a sump was excavated in the creek bed near the road culvert of the access road, downstream of the pond water discharge point. 11,000 litres of clean water were used to flush the stream between the pond and the downstream road culvert. Water collected in the sump during the flushing process was pumped to the adjacent leachate pond and treated as leachate.

(g) leachate collected from the western area of the site in sedimentation pond B was directed into the main leachate pond;

(h) all sedimentation ponds at the tip were desilted;

(i) all rubbish was removed from the creek and adjacent areas.

33. Further samples were taken by the defendant at the Wilton Road Creek on 11 August 1997 and were analysed for pH, total suspended solids, BOD, COD, ammonia and oxidised nitrogen.

DATE OF SAMPLING

SAMPLE ID
SAMPLING LOCATION

BOD
COD
Total Suspended Solids

PH
Ammonia
Oxidised Nitrogen

11 August 1997
D0782/087/5

Upstream
6 mg/L
13 mg/L

10 mg/L
6.2
0.13 mg N/L
0.07 mg N/L

11 August 1997
D0782/087/5

Discharge Pt
300 mg/L
423 mg/L

111 mg/L
6.8
22.6 mg N/L
0.05 mg N/L

11 August 1997
D0782/087/6

Downstream*
491 mg/L
592 mg/L

107 mg/L
6.8
31.9 mg N/L
0.03 mg N/L

Again, the downstream sample was taken in the vicinity of the prosecutor’s sample S4.

34. Since 11 August 1997 further works have been carried out at the Awaba Tip. These may be summarised as follows:

(a) a new drainage line has been constructed to collect all run-off water from the surrounding bushland and direct that water to siltation ponds on the western side of the tip. When the western catchment drain is stabilised it will be altered to by-pass the siltation ponds and thus flow directly back into the bushland;

(b) three new siltation ponds have been constructed (ponds P2, P3 and P5) to control run-off from the disturbed areas of the tip;

(c) the drainage line from pond P2 has a pipe overflow to reduce siltation and scouring from that pond and extending under the entry road and then discharging into bushland;

(d) the former siltation pond from which the leachate escaped into the creek was, as has been noted above, desilted and was then converted to form part of an enlarged leachate pond together with the original leachate pond L1;

(e) siltation pond P2 acts as a silt barrier to the quarry area where material is won and used as cover material on the tip;

(f) new stormwater berms have been constructed and will continue to be constructed as the configuration of the tip alters with waste disposal.

(g) new berms have been constructed and will continue to be construed to direct leachate to the leachate pond. New berms have been constructed and will continue to be constructed around the base of the landfill;

(h) a three inch capacity spray irrigation pump has been installed (at a cost of $35,000). The pump is used to spray, irrigate and aerate leachate over the rehabilitated areas of the landfill;

(i) the respondents Survey Planning Service has carried out a survey of the tip and calculated hydraulic capacities in order to be able to cope with 1 in 25 year rainfall events. Stabilisation of the perimeter diversion drain has been carried out;

(j) Coffey Geoscience Pty Ltd has been engaged to prepare a design of the quarrying area, previously used to provide fill to cover the waste, so that a new garbage disposal cell can be constructed therein;

(k) weighbridges were installed to firstly comply with the Waste Minimisation and Management Act and secondly to accurately measure the quantities of waste received. This will assist in planning the filling patterns and construction needs of the landfill. The installation of weighbridges cost $320,000;

(l) the defendant has authorised the appointment of a Waste Site Supervisor with tertiary qualifications in environmental science or engineering. This person’s role will be to concentrate on operational issues of the tip and will involve an annual cost to the respondent of about $50,000;

(m) the defendant is currently advertising for a Waste Planner whose role will include planning for the future operation of the Tip and whose duties will commence in January 1999. This will involve an additional annual cost to the respondent of approximately $55,000;

(n) the defendant has installed sampling bores on the lower area of the site for the purpose of ground water monitoring (at a cost to the respondent of $10,000);

(o) apart from the abovementioned costs, described in subparas (h), (k), (l) and (m) above, the works which the defendant has undertaken thus far and which have been summarised above has resulted in the incurring of expenditure of more than $500,000, excluding salary and wages.

35. The defendant’s advisers, Coffey Geosciences Pty Ltd, have recommended the carrying out of more detailed background studies, following which further tasks should be completed:

· the formulation of a management plan and design cell system;
· the construction of cells;
· the upgrading of leachate control measures as required;
· the upgrading of surface stormwater controls;
· the upgrading of erosion and sediment control measures.

The respondent has now authorised the expenditure of $1 million for the carrying out of these further studies and the foreshadowed works resulting therefrom.

36. Works carried out on the Awaba Tip since 7 August 1997 have resulted in increases in leachate and stormwater holding capacity as follows:

LEACHATE PONDS
August 1997 August 1998

P1 - 1550
L1 950 1130
L2 - 890

______ _____
950 3570
All measurements in m3
SEDIMENTATION PONDS
August 1997 August 1998

P1 550 -
P2 180 1030
P3 - 130
P4 150 310
P5 - 300
______ _____

880 1770

All measurements in m3


The cause of the incident

37. The cause of the incident on 7 August 1997 was inadequate and poorly working stormwater and leachate management systems on the Awaba Tip prior to that date and which the defendant admits was due to its negligence.

38. The stormwater and leachate management system failed to work adequately after a period of approximately 8 - 10 days continuous rainfall during the period of about 26 June 1997 to 5 July 1997.

39. The discharge of leachate into the Wilton Road Creek was the result of leachate not being diverted to the designated leachate pond (referred to in the evidence as “leachate pond B”) and instead running into a sedimentation pond (referred to in the evidence as “sedimentation pond B”). Sedimentation pond B was full of sediment and silt because it was not being properly maintained. That is to say, the sediment pond had not been desilted regularly as it should have been. The excess sediment and silt in sedimentation pond B caused the leachate to breach the pond wall and discharge into the Wilton Road Creek.

40. The common best practice is to clean out and maintain sedimentation ponds on a regular basis and at least when the design capacity or less remains in the settling zone. There are two main components in a sediment pond: the settling zone and the sediment storage zone. The settling zone is where the water is stored to allow the settlement of suspended solids.

41. Leachate and stormwater at the Awaba Tip were not being separated prior to 7 August 1997. The ponds on the site were not being either inspected or maintained. Had leachate been diverted to the designated leachate pond, the discharge of leachate from the sedimentation pond B may not have occurred.

42. Prior to 7 August 1997 waste on the Awaba Tip was not being covered on a daily basis as required by the development consent conditions and in accordance with best practice. If the waste had been covered daily, the amount of leachate being generated would have been reduced, as rainfall on the site would not have had the opportunity to percolate through the waste material, thus generating leachate.

43. In accordance with best practice, if an area is to be disturbed for a period greater than 30 days it should be stabilised. If areas are not stabilised, greater soil erosion and run-off is created. If soil is not stabilised and becomes compacted, run-off increases as there is a reduced amount of infiltration into the soil.

44. According to Mr Merrett, he noticed a large amount of silt in sedimentation pond B three days before 7 August 1997 and he noticed leachate was present in and discharging from sedimentation pond B for 2 to 3 days before 7 August 1997. On 7 August 1997 all the sedimentation and leachate ponds on the tip contained leachate.

The discharge

45. The discharge of leachate from sedimentation pond B into the Wilton Road Creek occurred for approximately 2 to 3 days prior to 7 August 1997 and did not cease until approximately 4 pm on that day.

Rainfall data

46. According to the Bureau of Meteorology there was eight days of continuous rain between 30 June 1997 and 7 July 1997 (“the eight day period”) recorded at the Bureau’s Eraring and Swansea Stations. This was the wettest period which occurred before 7 August 1997. During the eight day period rainfall totalled 138 mm at Eraring and 184.8 mm at Swansea.

47. Eraring Station is approximately 6 kms from Awaba and Swansea Station is approximately 12 kms from Awaba. Rainfall records have only been collected at Eraring and Swansea Stations for the past 5 and 10 years respectively.

48. The Bureau’s analysis of the eight day period shows that the maximum rainfall totals over the first 24, 48 and 72 hour periods were less than a return period of a one storm event and therefore were not unusual. In comparing the maximum rainfall total for the eight day period with all records at both stations, wetter periods had occurred at both stations. The Bureau therefore concluded that whilst the rainfall over the period was high, it was not extreme and could be expected to recur.

49. Immediately before 7 August 1997 there were three continuous days of rain, between 4 and 8 August 1997 recorded at Eraring and Swansea Stations. During this period rainfall totalled 7.4 mm at Eraring and 34.6 mm at Swansea.

50. Rainfall records for the Newstan Colliery, which are not kept to the Bureau of Meteorology standards, approximately 6 kms from the Awaba Tip, indicate that a period of 10 days of continuous rain occurred between 26 June 1997 and 5 July 1997 totalling 108.2 mm. Those records also indicate that there was a period of three days of continuous rain between 4 August 1997 and 6 August 1997 totalling 12 mm.

Environment harm

51. The Wilton Road Creek is a small ephemeral creek that flows intermittently as a result of run-off from rainfall within its catchment. The Wilton Road Creek at the point below the Awaba Tip exhibits terrestrial vegetation, indicating that the flow in the creek is enough to allow plants to establish. The type of vegetation, particularly ferns and the presence of frogs in the area, indicate that the creek bed remains moist for some time. The existence of deep standing pools in the creek and the most conditions provides suitable habitat for aquatic fauna such as macro invertebrates (for example, insects and crustaceans, and frogs, albeit on an intermittent basis.

52. Background BOD levels for natural waters are normally in the range of 2-4 mg/L, while the BOD of raw sewage is in the order of several hundred mg/L.

53. It is evident from the results of samples S4 and S5 that the discharge of leachate into the Wilton Road Creek on or about 7 August 1997 significantly increased the biochemical oxygen demand in the creek and probably totally depleted the oxygen from the water for a distance of at least 240 metres downstream from the discharge point into the creek. BOD levels beyond that point would have been at acceptable limits.

54. Most aquatic organisms require some dissolved oxygen to survive. The absence of oxygen would have resulted in the death of most aquatic organisms relatively quickly - in the order of hours or less. The prosecutor accepts that adult frogs would not have been affected (since they would have been able to hop out of the way).

55. The amount of oxygen depleted from the Wilton Road Creek would have been approximately equal to the BOD values obtained from the samples taken from the creek. The normal level of dissolved oxygen in the Wilton Road Creek would have been unlikely to have exceeded 10-12 mg/L of oxygen.

56. The very high BOD values obtained for samples S4 and S5 from the Wilton Road Creek indicate that there was potential to remove all oxygen from the water in the creek during the period of the discharge of leachate for a distance of at least 240 metres downstream from the discharge point into that creed.

57. A total lack of oxygen over a period of three days is likely to have killed all macro invertebrates in the Wilton Road Creek at least for a distance of 240 metres downstream of the discharge point into the creek.

58. The high BOD values obtained from samples taken from Wilton Road Creek continued at least until 11 August 1997, 4 days after the discharge.

59. The Wilton Road Creek contains suitable habitat for a number of species of frogs, which have aquatic life stages (eggs and tadpoles).

60. During two surveys conducted on 12 August 1998 and 8 September 1998, seven species of frogs were positively identified as using the Wilton Road Creek habitat, or ponds associated with the creek, below the Awaba Tip. These species were the common eastern froglet (crinia signifera), striped marsh frog (limnodynastes peroni), spotted grass frong (limnodynastes tasmaniensis), Peron’s tree frog (litoria peroni), Tyler’s frog (literia tyleri), red backed toadlet (pseudophryne coriacae) and the dusky frog (uperoleia fusca). Only two species of these frogs would have had tadpoles at that time of the year.

61. No threatened or endangered species of amphibians were found during the survey. Those found were common to the region.

62. The eggs of all species of frogs detected in the surveys as being present in the Wilton Road Creek are laid in water or very moist situations near the edge of water courses and their tadpoles live in the water. As noted above, no adult frogs were affected.

63. It is likely that four out of the seven frog species identified would have been active in the Wilton Road Creek below the landfill at the time of the discharge of the leachate into the creek. These were the common eastern froglet, red back toadlet, striped marsh frog and spotted marsh frog. These four species were active at the time of the surveys in 1998 and their tadpoles were found in an adjacent catchment, a tributary feeding into the Wilton Road Creek below the Awaba tip but not in the Wilton Road Creek below the Awaba Tip. As already noted, however, only two of the species would have had tadpoles at that time of the year.

64. The defendant concedes that there was a likelihood of pathogens present at all the sample points which were relevantly affected by the leachate, thus presenting a risk to human health. It is not possible to say whether or not there was a risk to human health beyond 500 metres below the confluence of the two unnamed creeks.

65. Recovery of the affected creek would have taken weeks or months. As a result of the flushing operations conducted by the defendant, the water quality in the reach of the Wilton Road creek between the discharged point of leachate into the creek and the constructed sump, would have recovered more quickly. It is less likely, however, that the biological recovery of this section of the creek by macroinvertebrates and frogs would also have occurred more quickly as a result of the flushing.

Audit of Awaba Tip

65. On 24 February 1998 Ms L Silk, an officer of the prosecutor, conducted a compliance on the Awaba Tip, accompanied by Ms Bruce.

66. Ms Silk observed the following at the Awaba Tip:

(a) the western stormwater diversion drain at the tip was poorly maintained, containing a tree limb and various bits of rubbish. Mr R W Taylor, the defendant’s Waste Manager and Emergency Services Manager, states that the tree limb was placed within the western stormwater drain to slow the velocity of water therein;

(b) the leachate drain in the south of the tip was eroded and contained litter;

(c) leachate was seeping out of the eastern slope of the landfill, but was being directed to a leachate pond.

67. The executive summary of the compliance audit report refers to issues of concern at the tip, including a concern that the leachate barrier system, collection system and storage system may not be effective in preventing surface water and groundwater pollution.

Considerations in imposing penalty

68. It is convenient to consider the question of penalty by reference to the heads of consideration under the Environmental Offences & Penalties Act , s 9, together with other relevant considerations.

69 (a) The extent of the harm caused or likely to be caused to the
environment by the commission of the offence .

There is no dispute between the parties as to the extent of the harm caused or likely to have been caused in this case. This is set out in paragraphs 51-65 above. The discharge of leachate into the creek occurred for some two or three days before 7 August 1997 and the high levels of BOD continued for four days after the discharge. There was thus a total of about seven days of high levels of BOD in the creek which had the effect described in the abovementioned paragraphs. The harm was, however, limited in extent to a few hundred metres of the length of the creek. Neither was the harm pemanent; the creek would have recovered in a matter of months.

70. (b) The practical measures which may be taken to prevent, control, abate
or mitigate that harm.

The development consent which the defendant granted to itself, as noted in paragraph 7 above, contained a number of conditions of consent, together with a number of measures designed to ensure that there would be no pollution of waters downstream of the Tip described in the Environmental Impact Statement and noted in paragraph 8 above. Moreover, the Environmental Guidelines for Solid Waste Landfill had been published in January 1996 (as noted in paragraph 14 above). The Guidelines contained in that publication had not been observed by the defendant. If the conditions of the development consent and the measures described in the Environmental Impact Statement had been implemented then the polluting event would not have occurred. Likewise, if the Guidelines published by the prosecutor had been observed the polluting event would not have occurred. There were thus practical measures which were envisaged by the terms of the development consent which the defendant granted to itself, which was specified in the conditions of that consent, in the Environmental Impact Statement which was the subject of that consent and in the Guidelines, which not only could have been taken but should have been taken.

71. (c) The extent to which the person who committed the offence could
reasonably have foreseen the harm caused or likely to be caused
to the environment by the commission of the offence .

The offence, although not deliberate or intentional, was entirely foreseeable. It was the result of negligence. The immediate cause of the particular incident was the result of leachate not being diverted to the designated leachate pond and instead running into a sedimentation pond; and the sediment pond was itself full of silt and sediment because it was not being properly maintained. The defendant’s employee at the Tip, Mr Merrett, recognised the risk. I have referred (in paragraph 25 above) to the fact that some three weeks before the incident Mr Merrett had ordered a long-reach excavator to clean out the sediment pond, but it had not been delivered. Moreover, Mr Merrett had noticed not only a large amount of silt in the sedimentation pond, but that leachate was present in and discharging from the pond for two to three days before 7 August 1997. The less immediate cause of the particular incident was the large exposed area which had not been stabilised, again leading to the foreseeable consequence of high levels of sedimentation; and the failure to separate the leachate and stormwater run-off.

72. (d) The extent to which the person who committed the offence had control
over the causes which gave rise to the offence.

The defendant owned and operated the Tip. It was solely responsible for the manner in which the Tip was operated. No third party was involved and no circumstances which were not within the control of the defendant contributed to the incident.

73. (e) Whether, in committing the offence, the person was complying with
orders from and employer or a supervising employee.

This consideration is not relevant in this case.

74. Other considerations

As required by the Crimes Act 1900, s 493, I take into consideration the fact that the defendant pleaded guilty at an early stage. I also take into consideration the facts that this is a first offence, the defendant immediately responded to the incident in the manner described in paragraphs 29 and 30 above, the defendant took the further steps described in paragraphs 32 and 34 above to prevent any recurrence of the incident, the defendant has authorised the further work described in paragraph 35 above, the defendant has incurred the expenditure described in paragraph 34(h), (k), (n) and (o), and the defendant has decided to employ properly qualified staff as described in paragraph 34(l) and (m) above. Moreover, the defendant has now committed a further $1 million to implement the recommendations of Coffey Geosciences Pty Ltd noted in paragraph 35 above. These will amount to permanent measures which should prevent any repetition of the offence. Finally in favour of the defendant I take into consideration the fact that it is providing a public facility for the community and not for the purpose of making a profit therefrom; and that it must not only pay a fine but also pay the costs of the prosecutor, which fine and costs would fall upon the general body of ratepayers.

75. Against these considerations is the fact that the defendant is the Council of a local government area which itself has a responsibility to enforce and institute proceedings for offences arising under the Clean Waters Act : see Environmental Offences & Penalties Act , s 13(4)(a). The defendant should thus be setting an example for others, rather than itself committing a breach of that Act. It did not seek advice from Coffey Geosciences Pty Ltd until after the commencement of this prosecution. It has belatedly taken the steps which it should previously have taken to prevent the occurrence of the kind of offence for which it is now prosecuted. The audit of the Tip on 24 February 1998, noted in paragraphs 65-67 above, disclosed that some six months after the incident there still existed an unsatisfactory state at the Tip. I also have regard to the fact that the imposition of a fine is intended to act as a general deterrent.

76. Having regard to the principle of even-handedness, that is to say, taking into consideration the general pattern of penalties imposed by the Court in similar cases, and bearing in mind that the maximum penalty for this offence, in the case of a corporation, of $125,000 is reserved for the worst category of offence, I am of the view that a penalty of $40,000 is appropriate in this case.

77. I therefore make the following orders:

1. The defendant is convicted of the offence as charged.

2. The defendant is fined the sum of $40,000 for the offence.

3. The defendant pay the prosecutor’s costs determined under the Land & Environment Court Act 1979, s 52(2).

4. The exhibits, other than exhibit B, may be returned.

I certify that the 36 preceding pages are a true copy of the reasons for judgment herein of the Honourable Mr Justice Lloyd.

Associate
Dated: 04/02/99