5.3. The number of visible air emissions recorded by the defendant from the valveboxes/goosenecks of the 7A battery indicate the licence limits in condition 010.1 were breached on 51 days from 22 October 2001 to 28 February 2002, including on every day from 23 October 2001 to 13 November 2001 and on a further 29 days between then and 28 February 2002. […]
6. ENVIRONMENTAL HARM
i. Water Pollution
6.1. As a result of the incident approximately 11 megalitres of water containing levels of ammonia, phenols and cyanide in excess of the licence conditions flowed from the recovery basin into the Main Drain and from there to Allan's Creek and the Port Kembla Inner Harbour. The water also caused the presence of the oily residues and appearance identified in paragraphs 4.24 and 4.25 above.
6.2. This caused harm to the marine environment of the Main Drain and Allan's Creek. It polluted approximately 1.4kms of Allan's Creek and was responsible for the death of a large number of fish and other aquatic animals including crabs. The dead fish included luderick, bream, tarwhine, sea mullet, flat-tailed mullet, sand whiting, roach, 3-barred porcupine fish, juvenile stars, striped toad fish, juvenile pennant fish, trevally and eels. Around 200 dead fish were counted in one section of Allan's Creek during the morning of 23 October 2001. […]
6.3. On 8 November [2001], an officer from the prosecutor inspected Allan's Creek and did not see any dead fish. He saw ripples on the water which indicated to him that there were some fish in the Creek.
6.4. A survey conducted on behalf of the defendant by Marine Science and Ecology in May 2002 indicated that populations of those fish species measured in the survey had returned to above those recorded at the time of the previous survey in 1995 within 7 months after the incident. Fish populations at the time of the incident are likely to have been higher than in 1995 as action by the defendant since 1995 including Pollution Reduction Programs undertaken to reduce water impacts and accordingly improve the water quality in Allan's Creek would have contributed to an increase in the fish populations.
6.5. At the Main Drain licensed discharge point, the licence limits for the discharge of the chemicals ammonia, cyanide and phenol were exceeded for at least 15 hours from 8.00 pm on 22 October 2001 to 11.00 am on 23 October 2001. At the height of the incident the concentrations of ammonia, cyanide and phenols discharged to the Main Drain were approximately 7, 6 and 4 times higher than their respective licence limits. […]
6.6. In summary the effect of the discharge of the three chemicals, ammonia, phenols and cyanide were:
(a) Ammonia - The discharge of ammonia was responsible either alone, or in combination with the other chemicals and substances discussed below, for the death of the fish and marine life observed by witnesses from 22 to 26 October 2001. Short term exposure to ammonia may cause behavioural changes and death in marine organisms. The Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000 ("ANZECC guidelines") include guidelines for protecting aquatic ecosystems. The ANZECC Guidelines contain "trigger values", above which further investigation is warranted and below which levels are considered not to adversely affect the receiving waters. The ANZECC trigger level for ammonia at pH 8.4 in marine waters is 0.42 mg/L. The concentration of ammonia in samples taken from Allan's Creek were up to 33. 7 mg/L on 22 October [2001] at 11.25 pm being 80 times the "trigger" level, and up to 13 mg/L at 10.40 am on 23 October 2001 being 31 times higher than the "trigger" level.
(b) Cyanide -The cyanide levels discharged to the Main Drain and Allan's Creek would have had adverse effects on the aquatic organisms including fish and crabs present in the affected area of the creek and contributed to the death of those organisms. Cyanide is known to be a harmful chemical to aquatic organisms. The ANZECC "trigger" level for cyanide in marine waters is 0.004 mg/L. The concentrations of cyanide in samples taken from Allan's Creek during the incident were up to 1.31 mg/L on 22 October [2001] at 11.25 pm being 327 times the "trigger" level and up to 0.54 mg/L on 23 October 2001 at 10.40 am being 135 times the "trigger" level.
(c) Phenols - The phenols concentrations discharged to the Main Drain and Allan's Creek would have caused adverse effects on aquatic organisms and contributed to the death of fish present in the affected area of the creek. Phenol can be absorbed through the fish membranes causing disruption to the central nervous system. The ANZECC "trigger" level for phenol in marine waters is 0.4 mg/L. The concentrations of phenol in samples taken from Allan's Creek during the incident were up to 1.2 mg/L on 22 October 2001 at 11.25 pm being three times higher than the "trigger" level and up to 0.76 mg/L on 23 October 2001 at 10.46 am being two times higher than the "trigger" level.
6.7. The discharge of residues to Allan's Creek in the course of the incident also polluted the Creek as identified in paragraphs 4.24 and 4.25 above.
a) Public Complaints
6.8. Between 22 October 2001 and 29 October 2001 the defendant received 10 odour complaints which reported a strong odour from coke ovens. Of another 35 odour complaints, some identified the odour character as "acrid", "burning coal" or "sulphur". A further 26 complaints related to tar fallout on motor vehicles. The defendant cleaned about 40 cars as a result of the incident.
7. STEPS TAKEN BY THE DEFENDANT SINCE THE INCIDENT TO PREVENT A RECURRENCE
7.1. Steps taken by the defendant since the incident to prevent a recurrence include:
1 Restoration of plant condition
· Repair of the No. 5 ammonia absorber acid catches;
· Repair of the 7A battery collector mains to reseal each of the connections between the valvebox/gooseneck and the collector main.
a Hazard and risk management
· Engagement of an external consultant who led an environmental risk assessment of gas processing and coke batteries;
· As a consequence of the defendant's participation in the production of a joint statement between its experts and those appointed by the EPA on the question of risk assessments and associated issues and the range of matters discussed and addressed in conferences between these experts, the defendant agrees to work with the EPA to attempt to identify and address any outstanding concerns on the part of the EPA and its risk expert and to work closely with the EPA in respect of environmental risk management at the premises.
2 Process management changes
· Introduction of monitoring of the pH and sulphate levels in contaminated water from the final coolers to monitor acid carryover;
· Installation of an additional bolt to the flange set or alternate similar locating mechanism that secures the spray headers in on all sprays on the numbers 3, 4 and 5 ammonia absorbers to ensure the sprays are aligned with the gas flow. The modification will be introduced to the number 2 absorber on the next available shutdown at which time all sprays will have been modified;
· Implementation of procedures for managing process modifications comprising weekly change management meetings across Gas Processing and the Batteries to co-ordinate and record all changes in a database
· Improved manual sampling of the tar level in the No. 10 tar decanter, with associated procedures for all decanters to confirm the tar/liquor interface level indication from the instruments.
3 Capital improvements
· Installation of a holding tank system and associated procedures to ensure all gas main condensate to be returned to the process is analysed before it is introduced to the process;
· Enlargement of the emergency capacity of the recovery basin, which is now in progress.
4 Other
· Creation of additional "process specialist" and "process engineer" roles in Gas Processing in order to improve management of process performance and on process safety;
· Introduction of a new organisational model at all levels of the company which emphasises role accountability and ensuring that all aspects of managing the processes and business are adequately recognised and resources.
7.2. Further steps in progress or proposed by the defendant include:
· Installation of two conductivity meters to continuously monitor for ionic species in the 2 separate contaminated water streams;
· Extensive experimental testing of interactions between process liquids within the Gas Processing plant in order to identify possible impacts should cross contamination occur;
· Extensive review of emergency response procedures applicable to the cokemaking operations;
· Initiation of a cokemaking technology agreement with a major European steelmaking and engineering firm in order to enhance access to state of the art technical information;
· Testing of a supplementary device for monitoring the tar/liquor interface in decanters in a way which will indicate any loss of effectiveness of separation.
36 CO-OPERATION WITH THE PROSECUTOR
7.3. During the incident, on 22 October 2001, the defendant accompanied Mr William Dove and other officers of the EPA around the defendant's site to inspect the effects of the incident and to ensure the prosecutor understood the incident and the steps taken by the defendant to mange the incident.
7.4. On 23 October 2001 the prosecutor requested an incident report in accordance with condition R3.3 of the defendant's licence. The defendant provided a comprehensive incident report on 23 November 2001.
7.5. On 14 February 2002, the defendant was issued with a notice under the POEO Act for information and records in respect of the incident. On 27 March 2002 the defendant supplied extensive information and records in response to this notices.
7.6. On 7 May 2002, the defendant was issued with a notice under the POEO Act for information and records in respect of the incident. On 14 June 2002 the defendant supplied extensive information and records in response to this notice.
7.7. On 5 July 2002, the defendant was issued with a notice under the POEO Act for information and records in respect of the incident. On 19 July 2002 the defendant supplied extensive information and records in response to this notice.
7.8. On 7 August 2002 the defendant hosted a visit to the site by Mr Dove and the prosecutor's expert witness Mr John Court in order to assist them in their fact finding.
7.9. On 3 October 2002, the defendant was issued with a notice under the POEO Act for infoffilation and records in respect of the incident. On 31 October 2002 the defendant supplied extensive infoffilation and records in response to this notice.
7.10. On 3 November 2003, the defendant hosted a visit to its site by legal representatives and experts retained or employed by the prosecutor.
7.11. The defendant co-operated with the prosecutor during the investigation of the incident and in the preparation of this statement of facts.
7.12. The defendant has agreed to pay the prosecutor's costs as agreed or assessed.
7.13. The defendant pleaded guilty to the charges on 17 December 2002, the second mention date, which the parties accept was the first reasonable opportunity for the defendant to do so.
ANNEXURE 2
Land and Environment Court Proceedings 50106 to 50111 of 2002
EPA v BHP Steel (AIS) Pty Limited
37 Supplementary Statement of Agreed Facts
10 Immediate Cause of the Incident
10.1 It is agreed that the following sequence of events led to the incident -
(a) Emulsification of tar/liquor occurred in the No. 10 decanter with the decanter ceasing to operate effectively to separate tar from the flushing liquor.
(b) This led to emulsified tar being contained in the flushing liquor. The emulsified tar in the flushing liquor caused blockages in the 7A battery cooling sprays, thus causing the collector mains of the 7A battery to become overheated. This risked permanent damage to the collector mains.
(c) Fresh water was introduced to provide emergency cooling of the collector mains of the 7A battery. This was introduced in place of the circulating flushing liquor to cool the coke gas. As the volume of fresh water introduced was in excess of the capacity of the flushing liquor system, a surplus of contaminated water overflowed from the No. 10 decanter and from there collected in the recovery basin. The volume of water necessary to maintain cooling of the gas main over a period of 27 hours exceeded the capacity of the recovery basin and from there discharged to the Main Drain and Allan's Creek once the capacity of the recovery basin was exceeded.
(d) An attempt to divert a portion of the surplus water through the quenching process to minimise the overflow of contaminated water to Allan's Creek was thwarted because tar had spread through the Industrial Water System which resulted in the yellow quench plume referred to in paragraph 4.12 of the Statement of Agreed Facts.
(e) The collector mains on the 7A battery warped due to overheating thereby loosening the seals of the connections between the valveboxes/goosenecks and standpipes, thus permitting emissions of the coke gas to the atmosphere as specified in paragraph 5.3 of the Statement of Agreed Facts.
10.2 The primary or root cause of the emulsification of the tar referred to in 10.1(a) is not agreed. Enquiries and subsequent investigations have enabled the defendant to satisfy itself that the following sequence of events gave rise to the incident:
(a) A spray header was installed in the primary acid catch on the No 5 ammonia absorber in the gas processing plant at some time between 1997 and 22 October 2001. The spray header was incorrectly installed - it was aligned so that the liquor sprayed towards the inner sleeve of the primary acid catch rather than the same direction as the gas flow. This caused the spray solution to impinge directly onto the inner sleeve of the primary acid catch. The design plans showed the sprays pointing in the same direction as the gas flow.
(b) A combination of erosion and corrosion from this impingement of the spray solution caused the formation over time of a hole in the inner sleeve having approximate dimensions of 30 cm long by 2 cm wide. The formation of a hole resulted in sulphate carryover to the numbers 5 and 6 final coolers, and hence to the No. 10 decanter as part of the process by which the flushing liquor is recirculated.
(c) The sulphate circulating in the flushing liquor system reacted with tar chemicals to form a sulphonated compound which acted as a surfactant.
(d) The surfactant formed an emulsion in the No. 10 decanter.
It is agreed by the prosecutor's expert Mr John Court that this is a possible cause of the emulsification referred to in 10.1(a).
10.3 The prosecutors' expert Mr Court postulated that a more likely cause of the emulsification referred to in 10.1(a) was an unplanned an unauthorised introduction of a surfactant material into the No. 10 Tar Decanter. The defendant's experts do not agree that this is a more likely cause than that described in paragraph 10.2 above. However they do agree surfactant material, in breach of the defendant's work procedures and without the knowledge of the defendant, could have been dumped into a seal pot condensate collection tank and thereby returned to the process with returned gas main condensate. Both the prosecutor and the defendant's experts agree that:
(a) it is physically possible for surfactant material to be dumped into a seal pot;
(b) emails relating to overseas experience indicate unplanned introduction of surfactants from any source are a potential source of emulsification; and
(c) there is no direct evidence linking such an event with the incident.
10.4 The supply of clean flushing liquor to the batteries, in order to provide cooling to the collector mains, is a critical aspect of the cokemaking process. Effective decanter operation in order to achieve efficient separation of liquor from tar and is a key part of the flushing liquor supply. Emulsification interferes with efficient separation in the tar decanters. It is agreed that there are several reasons why emulsification can occur:
· Fine solids entrainment from the coke ovens or other sources.
· Contamination with mineral oils.
· Contamination with detergents or other surfactants (from sources outside the cokemaking plant).
· Generation of surfactants within the cokemaking process (eg. Via sulphonation).
· Strong ionic solutions (including strong alkali and sulphuric acid).
· Other unexplained causes, given the complexity of the coal tar chemistry.
ANNEXURE 3