Herbicides/Toxics - Updates to March 2005

Aug 06: Hancock pollutes Geelong Drinking Water with Hexazinone for 18 months (and counting)

Environmental groups call for bans on aerial spraying of pesticides

Modes of Actions of herbicides

Nightmare Unfolding in Tasmania

Bluegum plantation insecticides

Atrazine and Hexazinone incident that killed 100 old growth redgum trees at Rosedale between 2000 and 2002.

FSC Board Committee Decision Regarding Simazine Use in Victorian Plantations 3/11/03

Chemical Policy of the Forest Stewardship Council

Historical data on 2,4,5-T use in Victorian Plantations

The Continuing Health Problems Associated with 2,4,5-T

Chlorinated Pesticides

Tip of the iceberg (March 03)

Water supplies and towns downstream of Hancock plantations (update)

Plantations, Gold Mining and Mercury pollution

• Atrazine: Possible Cause of Global Decline of Frogs
• Industrial waste sold as fertiliser
• Foreign fertilisers do not need warning labels
• How industrial waste gets into the food chain
• Buffer strips and streamwater contamination by atrazine and pyrethroids aerially applied to Eucalyptus nitens plantations
• HERBICIDE SPILL ALONG RED HILL ROAD, TRARALGON SOUTH - 26 May 1998 - STRZELECKI RANGES.
• ROUNDUP UPDATES

Atrazine and Hexazinone (Forest Mix WDH*) incident that killed 100 old growth redgum trees at Rosedale between 2000 and 2002.

Friends Block Background

1 The site

Friends Block (now owned by Grand Ridge Plantations (GRP) is located approximately 6km south of Rosedale. The district has a long grazing history. The site receives roughly 700mm of rain per year and is about 50m ASL. The landform is gently undulating to flat, with locally dissected drainage ways, or on flatter parts, shallow irregularly scattered depressions. The parent material is unconsolidated alluvial deposits of the late Pliocene age. The soils are a yellow duplex textured soil, with a loamy sand surface horizon over a yellow-brown mottled and generally dense clay. The block is about 450ha in size.

2 Past activities

In 2000, the Friends Block was site prepared and planted in Pinus radiata by Australian Paper Plantations. The site had in excess of 100 old Red Gum trees on site, which were deliberately protected and left intact at time of site preparation and planting. A different herbicide was used to that used normally, which was believed to have a lesser effect on native trees. No herbicide was sprayed around the native trees but this appears to have been inadequate protection. On this block we applied "Forest Mix WDH*" @ 7.2Kg/Ha. Apparently, following herbicide application a strong rain event occurred, resulting in water from the general establishment area pooling around the base of the native trees. The water was slow to get away due to the duplex nature of the soil.

March 2003: Poisoned redgums - Friends Block

3. Unacceptable outcome

Unfortunately, many of the Red Gums on the Friends Block have died since the site was established. This was brought to the attention of GRP in late 2002.

The patterns of tree death have been investigated, and there are some parts of the block that have had very few deaths, whereas other parts have been heavily affected. There doesn't appear to be any patterns of death that can be related to topography or location within the block. It would appear that the combined effect of herbicide, cultivation and fertilisation has caused the rapid death of most of these trees. It is likely that the herbicide was the main factor.

GRP has undertaken additional investigations including, analysis of the leaves of alive trees in the block for chloride, an analysis of the dam water for chloride and herbicide and an analysis of the soil for residual herbicide levels. These investigations have failed to turn up any additional information and there was no residual herbicide found in soil or water.

4. GRP response

After the purchase of the Australian Paper business, GRP worked with the Regulatory Authority, Wellington Shire, in an attempt to mitigate the impact of the loss. Approximately 10,000 trees (local redgum and lightwood) have been planted in a biolink that stretches for 3 km along the main drainage line in the block. The biolink adjoins native vegetation at each end. This involved the removal of recently planted pine, fencing of the area, planting and tree guarding. The trees are currently about 50cm tall and growing well. The block is fenced and gated and signs have been erected to discourage any firewood getters. The redgums which have died, have hollows and must be retained for hollow nesting fauna.

The Rosedale Historical Society, who have taken an interest in this issue have been kept informed of developments.

*Forest Mix WDH is made by Macspred Pty Ltd (Ballarat). Active Contituents: 210 g/kg Hexazinone and 620 g/kg Atrazine used at a rate of 7.2 kg/ha.

FSC Board Committee Decision Regarding Simazine Use in Victorian Plantations 3/11/03

(Background in April 2003, Hancock Victorian Plantations approached the FSC in terms of gaining a derogation for the continued use of the herbicide Simazine in its hardwood 'plantations' in Gippsland - what follows is the FSC judgement in terms of this derogation)

FSC Board Committee Decision:

Simazine may be used in Victoria, Australia, for the residual pre-emergent control of grass and broadleaved weeds in Eucalypt plantation establishment, until September 2006, and subject to the following conditions:

1. A 'Pesticides Advisory Group' which consists of technical advisers and which has the support of key FSC stakeholders in Victoria and environmental, social and economic members of the interim Australian NI shall be established by the FSC Australia Contact Person prior to any application of simazine by FSC certificate holders.

2. The role of the Pesticides Advisory Group shall be to provide guidance on the conditions attached to this derogation, and to review the results of monitoring carried out by certification bodies of certificates applying the derogation. Certificate holders shall make all necessary information available to members of the Advisory Group to allow them to meet these objectives.

3. Until the Pesticides Advisory Group gives clarifying guidance, there shall be no application of simazine in domestic supply water catchments.

4. Simazine shall not be applied on sites with conditions in which simazine can move off-site or accumulate in water courses. Until the Pesticides Advisory Group gives clarifying guidance, there shall be no aerial application of simazine in certified operations.

5. Where simazine is used there shall be buffers around the edges of sites and along drainage lines to ensure there is no spray drift, contamination of waterways, or off-site impact on native vegetation.

6. The Pesticides Advisory Group shall provide specific guidance to be followed with respect to:

6a. pre- and post- application monitoring of water courses, buffers, native vegetation and soils in catchments where simazine is applied;

6b. determination of sites, soils and catchments where it is not appropriate to apply simazine;

6c. the use of alternative chemicals that are not on the FSC prohibited list and have a lower risk of negative on- and/or off- site environmental impacts;

6d. determining the "trigger value" for simazine and procedures to be followed when monitoring shows the trigger value has been exceeded or when simazine is detected in waterways;

6e. appropriate application methods, in particular under what, if any, circumstances aerial application is acceptable.

6f. appropriate controls under which simazine may, if at all, be applied in domestic water supply catchments.

7. The policies and procedures of certifications applicants shall be evaluated and confirmed by the certification body prior to the issue of a certificate.

Re: Simazine derogation (FSC-GUI-30-603)

On 3rd November 2003 the FSC Board Committee on Chemical Pesticides agreed to permit a derogation for the use of simazine in Victoria, subject to a number of conditions. The decision and the associated conditions are described in the FSC document FSC-GUI-30-603.

One of the conditions requires that a 'Pesticides Advisory Group' should be set up by the FSC Australia Contact Person to provide advice, prior to the application of simazine by any FSC certificate holder.

The role of the Pesticides Advisory Group will be to provide advice on the application of the derogation, and to review the results of monitoring when simazine is used under its conditions. For this purpose the Pesticides Advisory Group is designed to consist of technical advisors and to have the support of stakeholders and FSC members in Victoria.

During the review of the simazine derogation request it was clear that it would be highly useful if a Pesticides Advisory Group could be established to provide advice on any further derogation requests in Australia. This would ensure that derogation requests could be scrutinised by experts in Australia, prior to submission to FSC, and improve the quality and timeliness of the evaluation.

There would be obvious advantages if the Pesticides Advisory Group set up to provide advice on simazine use in Victoria could go on to provide further advice on subsequent chemicals issues in the context of FSC certification in Australia as a whole. For further information, please contact Mr Tim Cadman, FSC Contact Person in Australia (tcadman@certifiedforests.org.au).

Matthew Wenban-Smith (Head of Policy and Standards Unit - Forest Stewardship Council, Bonn Germany).

'Tip of the Iceberg'

Herbicide Regimes - March 2003: Hancock Watch has recently been given information pertaining to the quantity of herbicides sprayed in certain Hancock plantations in the Gippsland Region. This data was provided by Gippsland Water. Information is incomplete and doesn't give an indication of the full story associated with herbicide use by the company. Nevertheless it does shed some light on this important issue.

Hancock are currently attempting to get their Victorian operations certified by the Forest Stewardship Council. FSC requires that companies reduce their herbicide regimes and ban the use of certain chemicals. We call on Hancock to publicly release all details of herbicide applications over their entire asset base. If we are not privy to this information then that is an unacceptable outcome - especially if herbicides are aerially dropped into peoples drinking water.

The following links will provide information relating to plantations and their herbicide regimes over the past few years. Also see March 03 updates with information pertaining to a herbicide pollution incident which has killed old growth redgums in Central Gippsland.

Incomplete Spray Regimes can be found at (plantations inside domestic water catchments highlighted in blue); 93-72, 93-73, 93-82, 93-89-1, 93-90-1, 93-97, 93-106, 93-108, LEGL93-118, 93-119, LEGL 93-120

Water Supplies Update November 2006:

Water supplies most likely to be impacted by Hancock activities (in red):

For more detailed information on these potentially impacted water supplies, please go to connecting links:

http://www.hancock.forests.org.au/directory/regional.html

1. Acheron - Acheron River (Central Region: LEGL93-67, LEGL93-71)
2. Adelaide Lead - Tullaroop Reservoir (Ballarat Region: LEGL93- 39/1, 93-40/1, 93-41)
3. Agnes - Agnes River (Strzelecki Region: LEGL93-85)
4. Alberton - Tarra River (Strzelecki Region: LEGL93-92, 93-93, 93-96, Parish Bulga )
5. Albury/Wodonga - Murray River
6. Alexandra - Goulburn River (Central Region: LEGL93-67, 93-68, 93-70, 93-71)
7. Alma - Tullaroop Reservoir (Ballarat Region: LEGL93- 39/1, 93-40/1, 93-41)
8. Anakie - Korweinguboora Reservoir (Ballarat Region: LEGL93-54)
9. Avenel - Goulburn River
10. Ballarat - White Swan Reservoir (Ballarat Region:93-41 )
11. Bannockburn - Moorabool River (Ballarat Region: LEGL93-52)
12. Barmah - Murray River
13. Batesford - Korweinguboora Reservoir (Ballarat Region:LEGL93-54 )
14. Bealiba - Loddon River
15. Beechworth - Nine Mile Creek (Ovens Region: 93-138, 93-139)
16. Bellbridge - Lake Hume (Upper Murray Region LEGL's)
17. Bendigo - Lake Eppaloch
18. Benalla - Ryans Creek (Benalla/Mansfield Region: LEGL 93-65, 93-66/1, 94-16)
19. Bennison - Agnes River (Strzelecki Region: LEGL93-85)
20. Betley - Tullaroop Reservoir (Ballarat Region:LEGL93- 39/1, 93-40/1, 93-41 )
21. Bonnie Doon - Lake Eildon (Benalla/Mansfield Region: LEGL 94-17, 94-18, 94-19, 94-20)
22. Boorcan - Gellibrand River (Otways Region:LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
23. Bridgewater - Loddon River
24. Bright - Ovens River (Ovens Region: LEGL 93-129, 93-132, 93-133, 93-134)
25. Bulla - Rosslynne Reservoir (Ballarat Region: LEGL93-58)
26. Camperdown - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
27. Castlemaine - Lake Eppaloch
28. Chocolyn - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
29. Churchill - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
30. Cobden, - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
31. Cobram - Murray River
32. Congupina - Goulburn River
33. Daylesford - Stewarts Creek (Wombat Forest: LEGL 94-15)
34. Derrinallum - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
35. Devenish - Broken Creek/River
36. Devils Gully - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
37. Diggers Rest - Rosslynne Reservoir (Ballarat Region: LEGL93-58)
38. Dumbalk - Tarwin River (Strzelecki Region: LEGL 93-79, 93-80, 93-81, 93-82, 93-114, 93-117, 93-121)
39. Dunnolly - Loddon River
40. Echuca - Murray River
41. Eildon - Lake Eildon (Benalla/Mansfield Region:LEGL 94-17, 94-18, 94-19, 94-20)
42. Elphingstone - Lake Eppaloch
43. Euroa - Seven Creeks (Benalla/Mansfield Region: LEGL93-60)
44. Flowerdale - King Parrot Creek (Central Region: LEGL93-69 - Mount Robertson)
45. Foster - Deep Creek (Strzelecki Region: LEGL93-82)
46. Fryerstown, - Lake Eppaloch
47. Geelong - Korweinguboora Reservoir/Moorabool System/Wurdiboluc System (Ballarat Region: LEGL93-54, Midway Plantations, AKD Plantations).
48. Gellibrand - Lardners Creek/Gellibrand River Catchment (Otways Region: 93-48/1, Midway Plantations) )
49. Gheringhap - Moorabool River (Ballarat Region: LEGL93-52)
50. Ghotuk - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
51. Gisborne - Rosslynne Reservoir (Ballarat Region: LEGL93-58)
52. Glengarry - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
53. Glenormiston - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
54. Glenrowan - Fifteen Mile Creek (Benalla/Mansfield Region:93-66/1 )
55. Goorambat - Broken Creek/River
56. Happy Valley - King Parrot Creek (Central Region: LEGL93-69 - Mount Robertson)
57. Harcourt - Lake Eppaloch
58. Havelock - Tullaroop Reservoir (Ballarat Region:LEGL93- 39/1, 93-40/1, 93-41 )
59. Heathcote - Lake Eppaloch
60. Hedley - Agnes River (Strzelecki Region: LEGL93-85)
61. Hepburn Springs - Stewarts Creek (Wombat Forest: LEGL 94-15)
62. Inglewood - Loddon River
63. Inverleigh - Moorabool River (Ballarat Region: LEGL93-52)
64. Kerang - Murray River/Loddon River
65. Kiewa - Murray River from Wodonga
66. Laanecoorie - Loddon River
67. Lara - Korweinguboora Reservoir (Ballarat Region: LEGL93-54)
68. Lethbridge - Moorabool River (Ballarat Region: LEGL93-52)
69. Lismore - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
70. Macedon - Riddells Creek (Ballarat Region: LEGL 93-57)
71. Majorca - Tullaroop Reservoir (Ballarat Region: LEGL93- 39/1, 93-40/1, 93-41)
72. Maldon - Lake Eppaloch
73. Maryborough - Tullaroop Reservoir (Ballarat Region: LEGL93- 39/1, 93-40/1, 93-41)
74. Meeniyan - Tarwin River (Strzelecki Region:LEGL 93-79, 93-80, 93-81, 93-82, 93-114, 93-117, 93-121)
75. Meredith - Moorabool River (Ballarat Region: LEGL93-52)
76. Merino - Groundwater (South West Victoria: LEGL 93-21, 93-23, ITC Plantations)
77. Mildura - Murray River
78. Mirboo North - Little Morwell River (Strzelecki Region Allotment 98 Parish Allambee East)
79. Moe - Narracan Creek (Strzelecki Region LEGL93-121)
80. Molesworth - Goulburn River
81. Mooroopna - Goulburn River via Shepparton
82. Morwell - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
83. Mount Macedon - Riddells Creek (Ballarat Region: LEGL 93-57)
84. Moyhu - King River (Benalla Mansfield Region: 93-66/1)
85. Murchison - Goulburn River
86. Myrniong - Werribee River (Ballarat Region: LEGL93-54)
87. Nagambie - Goulburn River
88. Nathalia - Broken Creek (Benalla/Mansfield Region: LEGL 93-62, LEGL 93-65)
89. Newborough - Narracan Creek (Strzelecki Region LEGL93-121)
90. Newstead - Lake Eppaloch
91. Noojee - Loch River (LEGL93-118)
92. Noorat - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
93. Numurkah - Broken Creek (Benalla/Mansfield Region: LEGL 93-62, LEGL 93-65)
94. Oxley - King River (Benalla Mansfield Region: 93-66/1. Ovens Region LEGL 93-149, 93-150, 93-151, 93-152)
95. Paradise Valley- King Parrot Creek (Central Region: LEGL93-69 - Mount Robertson)
96. Piangil - Murray River
97. Port Albert - Tarra River (Strzelecki Region: LEGL93-92, 93-93, 93-96, Parish Bulga )
98. Port Franklin - Agnes River (Strzelecki Region: LEGL93-85)
99. Port Welshpool - Agnes River (Strzelecki Region: LEGL93-85)
100. Raywood - Lake Eppaloch
101. Riddell - Bulk supply from Sunbury (Ballarat Region: LEGL93-58)
102. Robinvale - Murray River
103. Rosedale - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
104. Rutherglen - Murray River
105. Seaspray - Merrimans Creek Strzelecki Region: LEGL93-106, 93-107, 93-108, 93-116, ex APM plantations)
106. Sebastian, - Lake Eppaloch
107. Seymour - Goulburn River (Central Region LEGL93-67, LEGL93-68, LEGL93-69, LEGL93-70, LEGL93-71 Midway Plantations).
108. Shepparton - Goulburn River
109. Simpson - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
110. South Purrumbete - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
111. St. James - Broken Creek (Benalla/Mansfield Region: LEGL 93-62, LEGL 93-65)
112. Strathfieldsaye - Lake Eppaloch
113. Sunbury - Rosslynne Reservoir (Ballarat Region: LEGL93-58)
114. Swan Hill - Murray River
115. Taggerty - Acheron River (Central Region: LEGL93-67, LEGL93-71)
116. Tallangatta - Lake Hume (Upper Murray Region LEGL's)
117. Tallarook - Goulburn River
118. Tallygaroopna - Goulburn River
119. Tangambalanga - Murray River from Wodonga
120. Taradale - Lake Eppaloch
121. Tarnagulla - Loddon River
122. Terang - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations) )
123. Tooborac - Bulk supply from Heathcote - Lake Eppaloch
124. Toolamba - Goulburn River via Shepparton
125. Toora - Agnes River (Strzelecki Region: LEGL93-85)
126. Trafalgar - Narracan Creek (Strzelecki Region LEGL93-121)
127. Traralgon - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
128. Traralgon South - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)
129. Tungamah - Broken Creek/River
130. Wangaratta - Ovens River (Ovens Region: LEGL's 93-124/1, 93-125/1, 93-127/1, 93-128/1,LEGL 93-129, 93-130/1, 93-131/1, 93-132, 93-133, 93-134-1, 93-141, 93-142/1, 93-143/1, 93-144, 93-145, 93-146, 93-147, 93-148, 93-149, 93-150, 93-151, 93-152, 93-153/1, 93-154/1, 93-155, 93-156, 93-176)
131. Warrenbayne - Baddaganinnie Creek (Benalla/Mansfield Region 93-63)
132. Warrnambool - Gellibrand River (Otways Region: LEGL 93-47/1, 93-48/1, 93-49, Midway Plantations )
133. Welshpool - Agnes River (Strzelecki Region: LEGL93-85)
134. Westbury - Narracan Creek (Strzelecki Region LEGL93-121)
135. Wunghnu - Broken Creek from Numurkah (Benalla/Mansfield Region: LEGL 93-62, LEGL 93-65)
136. Yackandandah - Nine Mile Creek (Ovens Region:LEGL93-136, 93-137, 93-138, 93-139 )
137. Yallourn North - Narracan Creek (Strzelecki Region LEGL93-121)
138. Yarragon - Narracan Creek (Strzelecki Region LEGL93-121)
139. Yarram - Tarra River (Strzelecki Region: LEGL93-92, 93-93, 93-96, Parish Bulga )
140. Yarrawonga - Murray River
141. Yea - Yea River/Goulburn River (Midway Plantations)
142. Yinnar - Moondarra Reservoir (Strzelecki Region LEGL 93-120, Moondarra)

Plantations, Gold Mining and Mercury Pollution

Numerous plantations in the Hancock estate in Victoria are located on top of areas that were mined for gold in the 19th Century. Plantations were established in these areas to stabilise disturbed soil and mine tailings. Will logging of these areas and the associated soil disturbance release mercury (and other toxins) into the environment? Are existing buffer zones on these areas appropriate to stop this insidious form of pollution?

"(a) Auriferous Areas. An aftermath of the gold mining era in Ballarat, Creswick and Castlemaine was the denuded and unproductive areas of worked-out diggings. Partly to put the land to better use and partly to hide an unpleasant sight, planting of such areas commenced in 1888 at Creswick and at Ballarat and Castlemaine in 1919. Under natural conditions the auriferous soils are too poor for satisfactory tree growth but when disturbed by mining operations a big improvement is often obtained. This is largely a reflection of internal soil drainage and root penetration; under natural conditions the soils are compacted with a relatively impervious B horizon underneath a shallow A horizon, but mining operations results in several feet of "loose" soils being created. Responses like this suggest that deep cultivation to 3 or 4 feet may give a big improvement in site where low quality is due to compacted soils and not inadequate soils depth.

When most of the mined land had been planted, activities extended to the surrounding low quality native forest. Generally these did not prove to be very satisfactory, so that further extension has been confined to the more favourable localities.

(b) Dredged gravels. During the 1890's and early 1900's gold dredging extended into the Ovens Valley and its tributaries. At the peak of operations more than 40 dredges operated in the valley destroying large acres of alluvial flats and leaving a churned up mass of course gravels.

An experimental planting of 80 acres of P.radiata at Bright in 1916 on dredge trailings was very successful, so that over the next ten years several hundred acres were planted. These areas are some of the best in the Bright group of plantations.

Areas dredged more recently are not so satisfactory. With improved techniques and processing, soils have been disturbed to much greater depths and too high a proportion of the finer particles have been washed out. On such areas tree growth has not been satisfactory and many are now being converted to pasture of a kind". (Exotic Forests and Land Use by K.J. Simpfendorfer - Victoria Forests Commission Forestry Technical Papers No.19 1967)

Not all of the gold mining areas now under Hancock plantations would have used Mercury but many may have. The following excepts may shed some light on this disturbing issue which in many cases could be toxic timebombs waiting to happen.

Plantation LEGL93-41 Glen Park Plantation: Feb 01. Black liquid oozing from plantation gully which was once mined for gold. Could this be Mercury?

Hancock plantations on top of old gold mine areas include: Ballarat Region (LEGL's 93-24, 93-29, 93-34, 93-39/1, 93-40, 93-41 93-53, 93-54, 93-55) Ovens Region (LEGL's 93-130, 93-136, 93-137, 93-138, 93-139, 93-141, 93-142, 93-132).

Following article sourced from: Environment Protection Authority: Mercury in the Freshwater Environment - The Contamination of waterbodies in Victoria as a Result of Past Gold Mining Activities - David Tiller 1990.

". . . losses from gold mining activities in the past 100 or so years has contributed far more mercury to streams and lakes in Victoria than erosion would have over the same period. . . Mercury was, and in places still is, used for recovering gold from crushed ore. The gold containing ore is crushed into fine particles, mixed with water to form a slurry, and then passed over copper plates coated with mercury. Mercury forms an amalgam (mixture or combination) with the gold. The gold is seperated from the mercury by vaporizing off the mercury, which can be recondensed and re-used. Unfortunately, during the process some of the mercury is lost from the copper plates to the slurry. The processed slurry, now called tailings or slimes, was either contained in dams or discharged to water courses . . .

In the aquatic environment very little mercury will be dissolved in the water column. Mercury tends to bind to organic particles (Sherbin 1979), which then settle out of the water column and accumulate in the sediment. Most of the mercury in an aquatic system will, therefore, end up in sediments. . . Many aquatic organisms can take up and accumulate mercury, either directly from the water column or via their food. Mercury is also thought to biomagnify at higher trophic levels . . . Human poisonings by mercury are usually the result of eating contaminated fish or molluscs. . . Methyl mercury tends to accumulate in various organs of the body, particularly the brain (OECD1974). . .

The re-suspension of contaminated sediment during high flows may lead to elevated concentrations in the water column . . . In general, elevated mercury concentrations in the water column are episodic events . . . Unfortunately, there are no sediment mercury criteria available . . . The erosion of mercury-contaminated tailings continues to be a source of mercury to the aquatic environment . . . It should not be concluded that all the old tailings dams in gold mining areas are contaminated with mercury, as the mercury amalgam process was not the only method employed to remove gold . . .

Fish can accumulate large amounts of mercury, mostly methyl mercury, from the environment. . . Invertebrates can also accumulate mercury . . . While there is some uncertainty in the literature, it is generally considered that mercury is taken up by biota primarily from the water column rather than through ingestion of food. . . "

Following article sourced from: Marine and Freshwater Resources Institute. Report No 49. Mercury Concentrations in Brown Trout (salmo trutta) from Eastern Victorian Waterways. By G. Fabris December 2002.

"In Victoria there is a history of pollution of otherwise pristine streams and lakes by mercury which was commonly used to seperate gold, by amalgamation, from crushed ore during the last century . . . Coller estimated that approximatley 950 tonnes of metallic mercury was lost in streams of the Great Divide by this process . . .

p3 While it is unlikely that acute poisoning (seizures, severe neurological impairment and death) would result from exposure to low doses of methyl mercury, it can produce harmful effects in humans at concentrations one tenth of those of inorganic mercury and it has been implicated in cognitive deficits in children (Dietz et al. 2000). The risk is that recreational fishers as well as sensitive sub-populations such as pregnant women/foetus, nursing mothers and their infants and children would be at risk of developing subtle to severe neurological problems due to persistent exposure to low doses of methylmercury . . . In Australia, the FSANZ Food Standards Code (FSANZ 2002) prescribes a Maximum Level (ML) of 0.5ug g-1(wet weight) for most fish . . . p13 Ovens River (Site 4) have mean mercury concentrations ranging from 0.23 to 0.81ug g -1 . . . " (The Ovens River readings were taken from three sites between Bright and Freeburg).

Following article sourced from: State of the Environment Report 1988. Victoria's Inland Waters. Office of the Commissioner for the Environment.

p88/89 "Aquatic Impacts of Gold Mining: Historical Impacts.

The major environmental impacts of mining occurred during the intensive and widespread activity of the 19th century rushes. They include:

i) Massive logging of Victoria's box, ironbark and other forests for timber for mine props and fuel accompanied clearing of vegetation for easier access to outcrops, and the wholesale removal of washdirt for panning. This led to heavy erosion of hill slopes and river banks, and resultant changes to the physical form of rivers and streams. Only some of this cleared land - usually on the more accessible river flats - was later converted to agriculture use but much, while exposed, became heavily eroded, often being literally stripped of all vegetation. While many of the early mining areas have reverted to bush, evidence remains of these activities - including the relative paucity of regrowth. Current erosion rates in some localities are still influenced by the impact of mining activity.

ii) Most streams within areas bearing gold deposits were subjected to intensive excavation of their beds and banks, crude engineering works, and diversion of waters. In certain areas, river beds were dug over several times. Many thousands of tons of sediment were washed down-stream. Combined with the effects of sediment from erosion, significant changes in stream morphology resulted both within and down-stream from gold mining areas. In the absence of scientific evidence, it is impossible to precisely evaluate the extent to which these activities have had an impact on individual water bodies, but many of the dramatic alterations effected during the gold rush period have persisted through to the present day.

iii) Leaching of tailing dumps, the passage of waste effluent from processing to streams, and in some instances the mobilisation of natural sources of metals during the course of mining, all contributed to the loads of heavy metals and trace elements - particularly mercury, lead, zinc, copper and arsenic - which exists now in significant quantities in the sediment of streams in former gold mining areas (e.g. Goulburn River, Bendigo Creek, Rasberry Creek, Lerderderg River). These persistent contaminants are particularly concentrated downstream from processing sites.

iv) The massive changes in stream morphology and hydrology, sediment and heavy metal inputs inevitably had a significant impact on instream biota, though the extent of these impacts also cannot be assessed scientifically because of lack of data. Changes in the distribution and range of native fish in streams in previously mined regions may have been initiated by these impacts. . . "

Atrazine: Possible Cause of Global Decline of Frogs

Article sourced from Pesticide Action Network North America (PANNA)

http://www.panna.org

http://www.panna.org/resources/panups/panup_20020510.du.html

Atrazine, the most commonly used herbicide in the U.S. and possibly the world, causes an array of sexual abnormalities including hermaphrodism (the development of both male and female sex organs) according to a new study published in the Proceedings of the National Academy of Sciences. The results may provide the key to a global mystery. The U.S. Environmental Protection Agency (EPA) is now in the process of evaluating the ecological impacts of atrazine, and we are encouraging the public to send in comments (see below).

For the last decade, scientists have documented a worldwide collapse in frog populations, and some believe that as many as 20 species are now extinct. Perhaps most surprising, frog populations have collapsed even in very remote, pristine areas. While the declines are well documented, the cause is a mystery; suggested culprits have included global climate change, habitat destruction, toxics, predation from introduced species and diseases. Now University of California at Berkeley researcher Tyrone Hayes may have found a key cause that would explain much of the decline.

Atrazine, is used in over 80 countries, and where it is used it is almost invariably found in streams, ponds and lakes. In the U.S., it is found in virtually all waterways. "[It] can be found in rain water, snow runoff, and ground water. There seems to be no atrazine-free environment," says author Hayes. The reason for this is simple: in addition to being widely used, it is also highly mobile and persistent in the environment. The EPA estimates that the average half-life of atrazine in aquatic environments is 167 days, and in the cold waters of Lake Michigan, it is 31 years. Atrazine flows downstream from farms where it is applied and is also picked up by winds and carried to remote areas. The EPA notes that atrazine "was detected in more than 60% of weekly rainfall samples taken in 1995 from agricultural and urban sites in Mississippi, Iowa and Minnesota."

While widespread atrazine pollution in the U.S. is well documented, U.S. pesticide manufacturers have long claimed that it is of little concern because the amounts normally found in the environment produce few obvious effects in laboratory studies. However, traditional toxicological studies use very high concentrations of atrazine and look for gross abnormalities. Hayes's low-dose study, documented subtle sexual abnormalities missed by traditional high-dose atrazine studies. The results of the study, if confirmed, may pave the way to a major rethinking of how toxicological assessments are done in the United States.

Atrazine is a known endocrine disruptor. Endocrine disruptors cause developmental harm in extremely low doses by interfering with hormonal triggers at key points in the development of an organism. Hayes' study shows significant sexual abnormalities at just 0.1 parts per billion (ppb)--30 times lower than levels allowed by the EPA for drinking water and 120 times lower than the 12 ppb EPA guideline for the protection of aquatic life.

The ubiquity of atrazine in the environment combined with an explanation of how very low concentrations might cause harm to frog populations could provide a key piece of information to unravel the mystery surrounding the decline of frog populations worldwide.

The EPA periodically re-assesses chemicals and is currently finalizing the ecological risk assessment for atrazine. Though this document is supposed to consider all the major ecological impacts, developmental impacts on frogs like those shown by Hayes' paper are not considered in their risk assessment model. In fact, impacts on amphibians are entirely ignored in their model, which only looks at mammals, birds, fish, aquatic invertebrates and plants. The EPA's conclusions, based on this flawed assessment are that "potential effects [are] likely to be greatest where concentrations recurrently or consistently exceed 10 to 20 ppb"--100 to 200 times the concentrations where significant sexual abnormalities were observed in Hayes' study. Though Hayes' results are mentioned elsewhere in the assessment, these risk assessment models are expected to form the basis of any EPA regulatory action.

* Write the EPA and urge them to include the developmental impacts of atrazine on amphibians in their risk assessment models. The EPA's "Environmental Fate and Effects Revised Risk Assessment" for atrazine states that: "One of the most important steps in problem formulation is the selection of the endpoints upon which the ecological risk assessment is to be based." By excluding developmental impacts on frogs, this document fails to accurately assess the likely impacts of continued atrazine use.

Comments should reference the docket number (OPP-34237C) in the subject and must be received by EPA on or before July 5, 2002. Comments can be sent via email or mail.
Email: opp-docket@epa.gov

Public Information and Records Integrity Branch,
Information Resources and Services Division (7502C)
Office of Pesticide Programs
Environmental Protection Agency
1200 Pennsylvania Ave., NW
Washington, DC 20460

Document Number in Subject Line: OPP-34237C

Background information on atrazine can be found on the EPA's atrazine re-registration Web page at: http://www.epa.gov/pesticides/reregistration/atrazine/

For further information on the EPA assessment of atrazine see:
http://www.epa.gov/oppsrrd1/reregistration/atrazine/efed_redchap_22apr02.pdf

For further chemical information on atrazine see:
http://www.pesticideinfo.org/PCW/Detail_Chemical.jsp?Rec_Id=PC35042

For further information on frog declines see:
http://dlp.cs.Berkeley.edu/aw/declines/

Sources:
"Feminized Frogs: Herbicide disrupts sexual groups," Science News Online, April 20,2002, Vol. 161, No. 16. Viewed on April 29, 2002,
http://www.sciencenews.org/20020420/fob1.asp; Hayes, T.B., et al. 2002.

"Hermaphroditic,demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses." Proceedings of the National Academy of Sciences, Vol. 99 (April 16):5476-5480,
http://www.pnas.org/cgi/content/full/99/8/5476;
"Popular weed killer demasculinizes frogs, disrupts their sexual development, UC Berkeley study shows," UC Berkeley press release, April 15, 2002; "Amphibian Declines: An Issue Overview" jointly published by the Federal Taskforce on Amphibian Declines and Deformities (TADD), Partners in Amphibian and Reptile Conservation (PARC), the Declining Amphibian Populations Task Force (DAPTF), and the Amphibian Conservation Alliance (ACA),
http://elib.cs.berkeley.edu/aw/declines/declines.pdf; and

"Reregistration Eligibility Science Chapter for Atrazine, Environmental Fate and Effects Chapter," April 22, 2002,
http://www.epa.gov/oppsrrd1/reregistration/atrazine/efed_redchap_22apr02.pdf.

Industrial waste sold as fertiliser

Graphic: Waste products used in agriculture

Big businesses across Australia are disposing of their industrial waste as fertilisers or soil conditioners to be spread on farms, vineyards and home gardens.

The material often contains potentially toxic substances and heavy metals such as arsenic, mercury, chromium and lead.

State government agencies encourage the practice in the name of recycling and farmers embrace it because it delivers cheap fertiliser. Corporations also can save millions of dollars in dumping costs.

Untreated slag from BHP's Port Kembla steelworks is being spread over dairy fields and crops in the southern tablelands.

Radioactive material from aluminium refineries in Western Australia is being poured onto big cattle stations. In Victoria, South Australia and Queensland, waste from zinc smelters, power stations, cement kilns and car-part manufacturers is turned into products for farms and home gardens.

The practice is perfectly legal.

In Australia, there is no national regulation of fertilisers and any material that has fertilising qualities can be labelled and used as such, even if it contains toxins and heavy metals.

There are no requirements to register the products with state agricultural departments or to stop them being marketed as organic, which some of them are.

The few state regulations controlling toxic heavy metals in fertilisers can disappear when an industrial waste is re-labelled as a soil conditioner.

The potential threat to human health posed by the waste is a matter of dispute.

Studies show that large amounts of heavy metals such as arsenic, cadmium and mercury can cause cancers, birth defects and neurological problems in humans. They also can be taken up by grazing animals and by many table crops.

State environmental protection authorities and agricultural departments believe that the levels in the recycled material are harmless.

But they rarely test the products, relying instead on data supplied by the companies producing the waste for assurance that it is not dangerous.

Dr Mark Conyers, a soil scientist with the NSW Department of Agriculture, says it is time for a public debate on an issue which is unknown to most consumers.

"One of the things that disturbs me is that they give these apparently detailed analyses on their products, but they don't give you analysis on the bogymen [heavy metals]," he said. "It is like they are not there.

"My feeling is that these things should not be dumped on agricultural land until they have been deemed to be safe."

Lee Bell, a member of the National Environmental Consultative Forum, said there appeared to be a lack of regulation.

"It is a scandal and a disgrace and I think that if the public were made aware of the implications of doing this there would be mass outrage," he said.

"They are trying to convince people that black is white, and that potentially toxic waste is actually good for your garden. I don't think that any sensible and informed people would be of that view."

Ben Cole, a spokesman for the Total Environment Centre, said any reuse of unscreened industrial waste in agriculture should cause alarm.

"Industrial waste is dangerous; it should be kept well away from agriculture and the environment," he said.

"The risk of exposure to undesirable levels of heavy metals and other pollutants is far too high.

"Many of these contaminants bioaccumulate. This means they can be passed through the food chain and into our bodies, and flow into waterways via run-off."

Foreign fertilisers do not need warning labels

In NSW and Victoria it is mandatory for bags of fertiliser to carry a warning if the product exceeds certain limits of certain heavy metals.

In NSW these are: Lead, 20 milligrams per kilogram; Cadmium, one milligram per kilogram; and mercury, 0.2 milligrams per kilogram.

The warnings spell out the fact that using the fertiliser may result in crop and animal products that exceed guidelines on maximum allowable levels of these three heavy metals.

It also warns that the metals may accumulate in your soil.

But a loophole exists whereby fertilisers produced in other states do not have to carry the warning labels, even if they are being sold in NSW and Victoria.

The same loophole applies to overseas products - which accounts for about 40 per cent of all fertiliser sold in Australia.

Products made in the United States and sold in supermarkets in Australia do not have to meet guidelines set down for the same products made in Sydney.

And if you take a walk around your local supermarket you will find there are typically no warning labels on these products.

Figures released to the Herald from one large Australian fertiliser manufacturer show a number of their products have higher levels of lead, cadmium and mercury than the levels which trigger the warnings.

Some products have levels up to 25 times higher for cadmium and mercury and up to 12 times higher for lead.

In January 2000, the United States Fertiliser Institute produced a list of 12 heavy metals and one radionuclide (a radioactive element called radium 226) which it termed "metals of potential concern" found in fertilisers.

On the list were cadmium, mercury and lead. But also included were nine other heavy metals - arsenic, chromium, cobalt, copper, molybdenum, nickel, selenium, vanadium and zinc.

There are no set limits for any of these materials.

Some toxic metals can be absorbed by vegetable crops:

Arsenic: Carrots, onions, potatoes and other root vegetables

Cadmium: Lettuce, corn, wheat

Lead: Fruits and grains

Dioxin: Zucchini, pumpkin, cucumber, carrots, lettuce and peas.

Boron: Corn

SOURCE: California Public Interest Research Group Charitable Trust.

How industrial waste gets into the food chain

Agriculture gobbles up recycled materials, but there are few checks on the practice, Gerard Ryle reports.

The names of the companies recycling industrial waste into agriculture read like a who's who of Australian business.

Alcoa, BHP, Boral, Intercast & Forge, and Iluka Resources all dispose of by-products either directly to farmers or indirectly to fertiliser companies who use them in their production process.

Other companies, such as Ford, Backwell-IXL and TiWest, have explored ways of turning wastes into garden or agricultural products.

Much of the recycling is done in the name of the environment, and big fertiliser companies who use material say there is nothing wrong with it.

For instance, sulphuric acid used in the making of phosphate-based fertiliser is recycled sulphur dioxide captured from the pollution stacks of Pasminco's zinc and lead refineries. And ammonium sulphate, a by-product from Anaconda's nickel smelter, is used as a source of nitrogen in compound fertilisers.

But while some recycling may be desirable, there is little monitoring by state agricultural departments. Safety issues are left almost entirely to the honesty of private industry.

"In the olden days the Department of Agriculture would have done random checks on products to make sure they were what they were," said Dr Mark Conyers, a research scientist with the NSW Department of Agriculture.

"Today there are no inspectors. There is no compliance testing. There is just a labelling requirement, and if someone says 'I am not happy with the information, I am going to get a second opinion' it is up to the individual consumer to challenge the company."

The Herald has learned that there are no national laws on the level of contaminants allowed in recycled materials used in agriculture.

State fertiliser laws are restricted to just three heavy metals - lead, mercury and cadmium. Other potential hazards are ignored.

As a result some farmers can find themselves sprinkling several cups of arsenic over their lands when they follow recommendations on one recycled material for higher crop yields.

Arsenic has no nutrient value for plants and is considered injurious to human health. It can also be ingested by animals and some table vegetables. But, with a number of other toxic substances, such as uranium, chromium and nickel, it is in some recycled wastes.

"It is hard to get hard numbers out of data about what are safe levels of arsenic, or even lead, mercury and cadmium," said Dr Conyers. "You might get data on what is safe on potatoes in Tasmania but you don't get general information on what are safe levels in soil. The numbers are very rubbery.

"What we do know is that there are problems with lead, mercury and cadmium, and there are suspected problems with arsenic and chromium in some industrial waste products."

The recent explosion in using waste in agriculture appears to have coincided with two events.

The first was a general push by state environmental protection authorities to encourage recycling by raising disposal costs for hazardous materials.

The second was the abandonment, state by state, of rules that required the registration of fertilisers. These rules had been around for decades and NSW was one of the last to get rid of them.

In 1998, NSW was one of the last states to abolish the need for companies to list their products and their all-important contents.

"Companies are often looking for ways to bulk out products from cheap waste material," said Angela Thomas, technical manager for the fertiliser company, Yates, which does not use any dangerous byproducts. "I can't actually quote anything for you, but I wouldn't be surprised. There is such a drive at the moment for people to find alternatives for their waste products.

"I suppose some companies would see that it would be a good way to get rid of materials that they couldn't get rid of elsewhere," Ms Thomas said.

Even those who make their living from selling the recycled products to farmers are amazed at the lack of regulation.

Richard Clarke, who sells steel and cement-making wastes and incinerator ash from the burning of Canberra's sewage, says he is never bothered, even by the EPA.

"The Department of Agriculture used to keep an eye on us and this is the crazy thing," he said. "It has all become truth in labelling and it is a very big open market now because of the cutbacks the State Government have made." Mr Clarke, who tests all materials offered to him for safety before selling them to farmers, said he knocks some of them back, even when industries offer them free.

"There are products that are out there that are just no good," he said. "The Government says it is concerned about the environment, but then why isn't the Government controlling a little bit more what is going on the ground?"

But it appears that some recycling is being done with the active encouragement of state authorities.

For instance, at Townsville's Sun Metals Corporation, the world's third-largest zinc smelter, a waste gypsum is blended with natural gypsum, and then spread over cane fields and banana plantations. The waste product contains heavy metals, such as lead, cadmium and mercury, but the blending process brings it below Queensland's allowable levels for agriculture.

"We don't make any money on it. We are just trying to get rid of a waste product and get it reused for a better purpose than what we would do with it in terms of just putting it into a lime pond for storage and ultimately for capping and sealing," said the company's environmental officer, Eddie Boggiano.

"We have a licence from the EPA and they are aware of that; and also Burdekin Lime Company [which mixes the product] has an environmental licence whereby they can transport the gypsum, because it is considered a waste from here and it should be tracked."

Similarly the recycling of waste from Blue Circle Southern Cement at Marulan has drawn effusive praise from the CSIRO.

"Blue Circle Southern Cement sell their 'pollution' to farmers for $130,000 a year," says one CSIRO document on sustainable resources.

In fact the company is now saving about $200,000 a year more by adopting a program on recycling lime kiln dust to farmers.

What was once a waste is now a product called "hot-lime". The extra savings come in the form of lower EPA licensing fees, said the company's general manager of minerals, Allan Starr.

According to Mike McLaughlin from the CSIRO, who is in charge of a national program to monitor cadmium contamination in soils, much of the recycling simply makes sense. "A lot of the waste streams are very useful," said Dr McLaughlin. "Sulphur used to be put out into the air, but this can now be captured and used to make fertilisers.

"Rather than paying for sulphuric acid, you are taking a pollutant that would be going into the atmosphere and using it to substitute for a mineral that would have to be mined out of the ground anyway."

It is a point repeated by Craig Heidrich, a spokesman for the Ash Development Association of Australia. This is a body seeking alternative uses for Australia's estimated 12 million-tonne annual discharge of waste ash from coal-powered generating stations.

"There is a lot of fear and paranoia about using a so-called industrial waste for that type of application - it breeds the usual sort of scepticism," he said, but "from an environmental standpoint, from a nutrient standpoint ... this has no negative effects."

Jim Devine, a spokesman for Macquarie Generation, which recycles coal ash waste from the Bayswater Power Station into a tree plantation, said the material would otherwise have to be buried at great cost.

"We see it as an opportunity to capitalise on what has traditionally been regarded as a liability, that's for sure," said Mr Devine. "Every tonne we can divert from the [disposal] dam defers construction of the next dam. It is an expensive business maintaining it where it is at present."

But Lee Bell, a member of the National Environmental Consultative Forum, said some recycling was little more than legalised dumping and is not being properly monitored.

"The miraculous development of some industrial wastes into so-called fertiliser doesn't seem to have any regulatory control at all," Mr Bell said.

"It seems that if you can give waste some name that relates to improved farm yields, then it is fine to put it on the market. The regulators don't seem to be able to cope with that."

The following information sourced from:
"Buffer strips and streamwater contamination by atrazine and pyrethroids aerially applied to Eucalyptus nitens plantations"
Jan L. Barton and Peter E. Davies
Inland Fisheries Commission, 127 Davey St, Hobart, Tasmania 7000.

"Summary

Concentrations of pesticides in streams draining 20 plantations of Eucalyptus nitens in Tasmania were examined in relation to buffer strip width. Atrazine concentrations on the day of spray in streams draining 15 plantations were significantly negatively correlated with riparian buffer strip width but not buffer quality. Concentrations following the first rain event and one month after spraying were highly positively correlated with day of spray concentrations and were only weakly correlated with other site characteristics. Streams with 30 m buffer strips had median atrazine concentrations less than 20ug/L at all times and these buffer widths are recommended for minimising short term ecological impact on streams.

In streams draining five plantations that were aerially sprayed with pyrethoroids alpha - or cypermethrin, pyrethoroid concentration and short term changes in drift (downstream movement) of stream invertebrates were highly negatively correlated with buffer strip width but with no other variable. Drift of stream invertebrates is recommended as a biomonitor for the contamination of streams with pyrethoroids on the day of spray, sensitive down to 0.1ug/L. Buffer strips of at least 50 m are recommended to minimise mortality of stream invertebrates from pyrethroid spraying.

Introduction

Strips of riparian vegetation, commonly called buffer strips, are frequently used in forest management as a primary conservation measure to protect streams (Clinninck 1985). These buffer strips of natural vegetation are often expected to serve a number of roles - the reduction of sediment and associated nutrient losses and the reduction of pollutant loads into surface waters; the maintenance of natural channel stability, stream habitat and of allocthonous energy inputs; the conservation of terrestrial fauna and floral communities; the provision of wildlife corridors; and the maintenance of aesthetic values (see Clinnick 1985). Despite these expectations and the frequent and established use of prescribed buffer strip widths in forest management in Australia (Cameron and Henderson 1979), Campbell and Doeg (1989), in a recent review of the impact of forestry on streams stated that: "although buffer zones along streams have been widely advocated to protect streams ... there have been no Australian studies to determine the effectiveness of, or appropriate widths for, buffer strips in forestry operations...".

The effectiveness of buffer strips in reducing contamination of surface waters is related to strip width, the nature of the strip vegetation and the strip's relationship with catchment topography. Asmussen el al. (1977) described a reduction in herbicide loads in surface waters passing through vegetated channels which was dependent on the efficacy of the strip to trap contaminated particulates. Other authors have observed the dependence of sediment and nutrient reductions in surface waters on buffer slope and vegetation type (Trimble and Sartz 1957, Wilson 1967, Barfield et al, 1979) and modelled them under a range of runoff conditions (Hayes and Hairston 1983, Hayes and Dillaha 1992). Such descriptions are, however, related to relatively uniform grassed systems in agricultural watersheds and not to be near-natural forest riparian systems more common in forestry. Borg et al. (1988) described the effect of removal of buffer strips on Western Australian streams on stream channel profiles and water quality in the only Australian study in this field.

Few studies describe the contamination of surface waters from forestry pesticide spraying operations in Australia. McKimm and Hopmans (1978) reported stream contamination of up to 10ug/L with 2,4,5-T in an aerially sprayed Victorian pine plantation in which streams had natural buffer strips ranging from 20 to 40 m in width. They reported, however, that no significant contamination occurred on the day of spray, indicating that the strips had protected the streams from aerial drift contamination. McAlpine and Weil (1990) reported minimal contamination of streams from aerial drift when granulated formulations of atrazine and hexazinone were applied to Western Australian plantations, but noted significant contamination to the characteristics of the riparian vegetation. Leitch and Flinn (1983) and Leitch and Fagg (1985), in relation to aerial spraying of Pinus radiata plantations for woody weed control, reported low concentrations of the herbicides hexazinone and clopyralid in stream water which were stongly dependent on rainfall. They attributed the low concentrations to interception of aerial drift by 30 to 40 m wide buffer strips combined with a low proportion of catchment area sprayed and accurate spraying techniques.

Application of chemicals for pest control is an intrinsic component of Tasmanian eucalypt plantation management. Atrazine, a triazine herbicide is used extensively at high application rates (4-12 kg/ha) during winter in the early stages of plantation establishment. It is also used widely in plantation establishment in south-eastern and western Australia. Davies et al. (1993) report the widespread and persistent contamination of Tasmanian streams draining sprayed Eucalyptus nitens (shining gum) plantations, with concentrations of atrazine ranging over six orders of magnitude up to 53mg/L on the day of spray. Contamination persisted for up to 16 months and was dependent on runoff. Atrazine is regarded as having significant effects on stream fauna and flora at concentrations above 20ug/L (Dewey 1986). The recommended WHO drinking water guidelines for this compound are 2ug/L (WHO 1992), while the ECE's current drinking water quality criterion for atrazine is 0.1 ug/L (Buser 1990).

Alphamethrin, a pyrethroid insecticide, is used to control outbreaks of gum beetles (Chrysomphtharta sp.) in young E. nitens plantations in early and mid-summer, and is aerially sprayed at low application rates (10-30g/ha). Davies and Cook (1993) studied streams draining a Tasmanian plantation following aerial application of the closely related pyrethroid, cypermethrin (alphamethrin is a partially resolved racemic mixture of cypermethrin isomers). They reported large increases in stream invertebrate drift (downstream movement), and toxic symptoms in fish, in streams with buffer strips less than 10m. Concentrations of cyper- and alphamethrin in the 0.1-1 ug/L range are lethal to aquatic macroinvertebrates (Stephenson 1982). This concentration range is frequently at the limit of analytical techniques due to the high adsorption characteristics of these compunds, making them difficult to sample efficiently in surface waters.

The environmental effects of aerial spraying of pesticides are partially mediated in Tasmanian forestry operations by the use of a range of buffer strip widths dependent on stream size (Forestry Commission 1992), combined with prescriptions on recommended spraying practices (Forestry Commission 1988). This paper describes relationships between the concentrations of atrazine in plantation streams and the characteristics of the spray site, including buffer strip width and quality. Observations were made on the day of spray, the day following the first major rainfall event after spraying and one month after spraying. The relationships are also described for alphamethrin and cypermethrin on the day of spray, using both the response of drifting invertebrates as an indicator of contamination and the reported concentrations, which are regarded as less reliable.