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Clear Water revival: tools for reducing nutrient enrichment and endocrine disruption

As many as 20 mills have receiving waters that are being overfertilized by nutrients, according to downstream testing in four monitoring cycles -1996, 2000, 2004, 2007 -done as part of the Environment...


July 1, 2008
By Pulp & Paper Canada

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As many as 20 mills have receiving waters that are being overfertilized by nutrients, according to downstream testing in four monitoring cycles -1996, 2000, 2004, 2007 -done as part of the Environmental Effects Monitoring (EEM) program. EEM was launched in 1992 to help Environment Canada assess the adequacy of the Pulp and Paper Effluent Regulations.

In 2005, Environment Canada created the Smart Regulation Project on Improving the Effectiveness and Efficiency of Pulp and Paper Environmental Effects Monitoring. It reviewed the key outcomes of the national assessment of the EEM Cycles 2 and 3, and in late 2005 issued a report entitled, Improving the Effectiveness and Efficiency of Pulp and Paper Environmental Effects Monitoring: A Smart Regulation Opportunity.

The report recommended, among other things, that mills showing nutrient enrichment (Environment Canada uses the term “eutrophication”) must adopt best management practices by 2010 at the latest. The recommendation also called on industry to develop a best practices guide, track effectiveness in reducing eutrophication and report on progress in 2007 and 2010.

In response, FPAC established a task force of industry experts in this field. They developed a Best Management Practices Guide for Nutrient Management in Effluent Treatment (BMP), which it released this April. It can be downloaded from the publications section of the FPAC Website (www.fpac.ca).

“The other reason we prepared this document is to encourage mills to submit a nutrient action program as part of the EEM program. It is a way to get out of measurements and into action,” says FPAC director of environment Roger Cook. He adds, “Environment Canada will be writing to mills over the coming months to ensure that they are aware of this opportunity and to provide the details.”

In addition to discussing nutrient enrichment, the role of nitrogen and phosphorous in biological treatment systems, their sources, management and analysis, the BMP presents six possible strategies for controlling nitrogen and phosphorous. It also discusses different analytical methods, feed equipment and much more.

The sources of these two nutrients, and solutions to reducing discharges of them, are mill-specific: what may work for one mill could be ineffective for another mill’s operation. For example, nitrogen sources in kraft mills come from lignin (and vary depending on wood type), black liquor and foul condensates. Phosphorous comes from the lime kiln area and boiler ash. In a recycle mill, extracts from the recycle fibre may be a source of nitrogen. There are numerous nitrogen-containing chemicals and nitrogen and phosphorous supplements. Shock loads from some mill procedures and spills can cause spikes in nitrogen and phosphorous releases to treatment systems.

These process sources of nitrogen and phosphorus are usually relatively small. In most treatment systems in the pulp and paper sector, purchased nutrients have to be added to maintain the high treatment efficiencies required in the biological treatment systems. This requires careful monitoring to ensure nutrient additions are in the correct range. Underdosing will cause the treatment system to malfunction, while overdosing will result in losses to the receiving water.

“We need to publicize the fact that there is this tool, this BMP guide available for mills to use,” Cook says. “I think that any mill will see a potential [financial] advantage here. The new analytical tools available to monitor effluents may require that mills make some investments or change their strategies and see if there is room for improvement. It will pay for itself if you use fewer purchased nutrients, which have doubled in price over the last two years.”

As well, Cook says, “The incentive we have provided with this tool through working closely with Environment Canada is that if mills that exhibit nutrient enrichment in their receiving waters do an action plan, they should not have to do field work under EEM until the action plan for reducing nitrogen and phosphorous is in place.” So, rather than a mill spending another $200,000 on the next EEM cycle just to reaffirm that it still has enrichment issues, alternatively, it can divert monies to solving the problem. “There is a fundamental belief that we should not spend endlessly on field-testing, but divert those funds to solutions,” Cook adds.

The 2010 target is manageable if mills start now, Cook thinks. “I hope mills take a look at the guide and see if there are any ideas in there they have not considered.”

Fish gonads

The specific reproductive issue Paprican is addressing is the ability of pulp mill effluents to affect egg production in fathead minnows. When Paprican exposed fathead minnows to mill effluents in the lab at concentrations up to 100%, they found that some effluents could completely shut down egg production in as little as one day, while others had no effect whatsoever, according to Greg Kaminski, Head, Environmental Effects Monitoring for Pulp & Paper, Science & Technology Branch, Environment Canada.

According to Kaminski, the term “endocrine disruption” is being used but, strictly speaking, has not yet been proven. “Only after we discovered and proved that there was an issue of smaller gonads in fish, did we think that there might be endocrine disruption substances in mill effluent,” he said. “For the purpose of the regulation of pulp and paper effluent, there is no mention of endocrine disruption. The end point is measuring the gonads. The underlying assumption of that is that if the gonads are smaller in the exposed versus the reference sites, then there is endocrine disruption.”

The Smart Regulation Project report recommends that, “Government and industry should work collaboratively and transparently to identify the cause of effluent effects on fish gonads and to find and implement solutions to address the cause,” and that industry should submit implementation schedules for addressing gonad effects by 2012.

Paprican began investigating endocrine disruption in 2000 and, in 2006, a national collaborative effort was formed with researchers from the National Water Research Institute, Paprican and the Universities of New Brunswick, Guelph and Prince Edward Island. Some of the money for the work came from the EEM program and $100,000 came all the way from Aracruz Celulose in Brazil.

The researchers drew up a list of five activities which would identify cost-effective mitigation strategies: Literature review; selection of diagnostic tools; identification of sources and causative agents; evaluation of mitigation options; and validation of implementation solutions. The first activity has been completed and work will begin this fall to develop diagnostic tools which will quickly detect evidence of reproductive impacts on fish without having to take fish through their entire life cycles.

Although the chemicals that cause the smaller gonads have not been identified, the idea is to use the tools in order to test all the different process areas of the mills; e. g., kraft mill brownstock washing effluents, bleach plant streams, (which itself has three to five different stages, each with its own discharge) and releases from paper or pulp machines. “There is nothing obvious. We just know it is there in some pulp and paper operations and it does not appear to be related to the type of pulping process employed,” says Brian O’Connor, program manager, Environment, FPInnovations.

Kaminski’s office set up a criteria that says if significant effects on fish gonads are shown across two cycles at a mill, that mill may put its cycle money into the national collaborative effort instead of into another cycle study. Some mills have already given their Cycle 4 EEM money to the collaborative effort to fulfill their regulatory requirements, and some are doing the same in Cycle 5. Currently there are seven participating mills located across Ontario,
Quebec and the Maritimes, include the Smurfit-Stone mill in La Tuque, QC and the Tembec mill in Tmiscaming, QC.

“For the future, we are looking at a better funding route for these Investigation of Solution tests,” says O’Connor. “The industry is committed to solving this issue but presently doesn’t have the resources to adequately fund the collaborative effort, so we are looking at other funding options.”

PPC