Environmental Science & Engineering - www.esemag.com - July 2005
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The need for the establishment of Canadian biosolids partnerships

By Ronald J. Leblanc

Aerial view of the Greater Moncton treatment plant.

There is an important need to recognize that the general public is not properly informed about wastewater treatment plants and biosolids. Wastewater treatment plant administrators and regulators must develop a strategy to improve the public image of their facilities, operations, biosolids and the industry.

To deal successfully with biosolids management, administrators and regulators need to have a good overview perspective and must be continually aware that public acceptance and confidence are crucial.

What are biosolids? The United States Environmental Protection Agency (USEPA) states that “biosolids are the nutrient-rich organic materials resulting from the treatment of sewage sludge (the name for the solid, semi-solid or liquid untreated residue generated during the treatment of domestic sewage in a treatment facility). When treated and processed, sewage sludge becomes biosolids, which can be safely recycled and applied as fertilizer to sustainably improve and maintain productive soils and stimulate plant growth”.

The European Commission further states that “the characteristics of sludge/biosolids depend on the original pollution load of the treated water, and also on the technical characteristics of the wastewater and sludge/biosolids treatments carried out…Due to the physical-chemical processes involved in the treatment, the sludge tends to concentrate heavy metals and poorly biodegradable trace organic compounds as well as potentially pathogenic organisms (viruses, bacteria, etc.) present in wastewaters. Sludge is, however, rich in nutrients such as nitrogen and phosphorous and contains valuable organic matter that is useful when soils are depleted or subject to erosion. The organic matter and nutrients are the two main elements that make the spreading of this kind of waste on land as a fertilizer or an organic soil improver suitable”. (European Commission Sludge Scientific and Technical report, and the EC report on the Implementation of Community Waste Legislation on Agricultural Use of Sewage Sludge)

Biosolids disposal options The USEPA states “that because of strict federal and state standards, the treated residuals (biosolids) from wastewater treatment can be safely recycled. Local governments make the decision (including but not limited to) whether to recycle the biosolids as a fertilizer, incinerate, or bury them in a landfill.”

Only biosolids that meet the most stringent standards as spelled out in the federal and state rules can be approved for use as a fertilizer. Now, through a Voluntary Environmental Management System (EMS) being developed for biosolids by the National Biosolids Partnership (NBP), community-friendly practices will also be followed.

The European Commission, furthermore, states that “once treated, sludge/biosolids can be recycled or disposed of using three main routes:

Recycling to agriculture (landspreading) either by way of solid or semi-solid biosolids;
Mono-incineration and co-incineration of biosolids with other wastes;
Landfilling. ” (European Commission Sludge Scientific and Technical report)

While ocean disposal is no longer acceptable, other options exist or are being developed, such as uses for forestry and silviculture, land reclamation, utilization of sludge in building materials and developing combustion technologies including wet oxidation, pyrolysis and gasification.

As well, a new process known as BIOSOL (available through the Innovations Foundation of the University of Toronto) removes metals and destroys pathogens in raw, secondary, or digested wastewater sludges. The resulting Class “A” Biosolids (as defined by the Canadian Council of Ministers of the Environment) can be used to produce marketable compost.

World options The following two examples illustrate a range, or variety of approaches, that can be used to dispose of sewage sludge and biosolids:

China - In parts of China, where water is precious, as part of their land management practices they have been using a single canal to provide irrigation for a succession of fields. They use mud from the canal bed, along with animal dung and human waste (still collected from some municipalities) as manure.

Taiwan - In Taiwan, because of the population density and the lack of land available for reclamation, landfilling, or biosolids application, researchers are looking into the possibility of making commercial building bricks with biosolids as an ingredient. The impetus behind the idea was to find new uses for the 670,000 tonnes of sewage sludge the island produces each year. Some believe that this will be a less expensive way of disposing of biosolids than other options, such as incineration.

Sludge from sewage works can be used to bulk up ordinary house bricks. "It's a win-win situation because it converts the wastes into useful materials and alleviates disposal problems," says Chih-Huang Weng, leader of the team at I-Shou University in Kaohsiung County that devised the process.

Although the solids Weng and his team added to the bricks were filtered from industrial effluent, he says domestic sewage would do just as well.

In a paper accepted for publication in Advances in Environmental Research, (www.NewScientist.com) Weng's team reports achieving their best results when sewage sludge accounted for 10 per cent of the material in clay bricks fired at about 900 degrees C. But the process worked even when the "biobricks" contained as much as 30 per cent sludge.

Manual of Good Practice for Biosolids In 2004, a best practice manual entitled ”Biosolids Management Program” was developed in Canada under Infraguide (the National Guide to Sustainable Municipal Infrastructure), managed by the National Research Council. While not as in depth as the USA manual of good practices for biosolids, the Canadian manual is a step in the right direction.

The USA manual resulted from a targeted collaborative project to develop a resource document for management of biosolids that addresses the issues to be considered when designing and implementing a biosolids management program. It was managed by the Water Environment Research Foundation (WERF) for the National Biosolids Partnership, a not-for-profit alliance between the Association of Metropolitan Sewerage Agencies, the Water Environment Federation, and EPA. The manual covers all issues related to biosolids, including design and implementation of management programs, safe handling and preparation, marketing, public education, transportation, and record keeping.

Costs While the costs of disposing of biosolids vary from country to country, and between methods, the European Commission’s report on sludge/biosolids indicates that the landspreading route is the least expensive, while landfilling and incineration entail the highest costs from an overall economic point of view. (European Commission Sludge Economic Report)

A report of the Water Environment Research Foundation, (WERF) “Treating and Managing Residuals and Biosolids”, states that “growing urban populations and rising costs have catalyzed the industry to find alternative means of dealing with solids; treatment and handling alone typically compose 50 per cent of wastewater utility costs”.

Pollution Prevention Policy based on source control With a view to shifting the majority of the cost associated with biosolids treatment from local authorities, farmers and citizens, to the industry or the source of the pollution, the European Commission is studying the integration of a Pollution Prevention Policy intended to reduce the introduction of pollutants into the wastewater at the discharger level.

The implementation of a Pollution Prevention Policy would help eliminate known sources of influent contamination from industry, hospitals, and other identifiable groups who contribute directly or indirectly to the degradation of biosolids quality.

Common sense dictates that a Pollution Prevention Policy should be implemented in Canada. As well, it is only logical that the responsibility for such a policy and the required studies and regulations should not rest primarily with municipalities but with senior levels of government.

Managing public support It is clear that properly managed biosolids have beneficial uses and they should be recycled. There is also no doubt, however, that there is a need to manage the public perception of biosolids.

The U.S.’s wastewater industry is now making a concerted effort to gain the high moral ground with biosolids management and they are working at the national level to make this happen. The National Biosolids Partnership (NBP) acts as a coordinator for the many regional management groups that are being formed.

The goal of the National Biosolids Partnership (NBP) is to promote and advance environmentally sound and accepted biosolids management practices that build public confidence within local communities. Producers, service contractors, and users - together with stakeholders from regulatory agencies, universities, the farming community, and environmental organizations - will have input into shaping NBP priorities through scientific and technical support and communications linkages relating to biosolids issues.

A public attitude survey in the U.S. (in conjunction with the Water Environment Research Foundation (WERF) 2003) found that people who had visited a wastewater treatment plant were significantly more likely to support biosolids recycling than those who had not. This is good; but how many wastewater treatment plants have visitor centres?

The WERF further reports that “properly treated products – reclaimed water and biosolids – are now considered excellent renewable resources. There remains, however, the looming issue of reducing uncertainties in the continued use of properly managed and treated biosolids – many reclaimed water and biosolids initiatives have failed due to lack of public support.”

The Environmental Agency (EA) of England and Wales launched its Vision for the Environment in January 2002. Inspired partly by the National Biosolids Partnership in the U.S., the EA decided to investigate the benefits and feasibility of an Advocacy Coalition Framework (ACF) to ensure quality and to promote good practice for use of organic resources on land. In order for the ACF to succeed it was recognized that endorsements were required from key organizations. As part of a consultative approach, the vast majority of respondents indicated that there was a need for better communication among stakeholders. In its conclusion, the report stated that there was an overwhelming belief among all stakeholders that an ACF is needed in order that the sustainable use of organic resources on land is adapted as an acceptable practice.

Gaps in knowledge While scientific research has been carried out, there are still gaps in knowledge. For instance, the Scientific and Technical report of the European Commission on Environment states:

“Today, many uncertainties remain concerning the transfer of pollutants (especially organic pollutants) to the environmental media and the food chain. Several issues would need to be more accurately documented. Amongst these issues, the following may be mentioned:

The importance of the runoff process in the pollutants’ transfer should be assessed. Mechanisms need to be understood, as well as quantities of pollutants concerned, and their fate.
An issue of concern is the degradation pathway of the organic compounds in soil.
Compounds may be degraded into intermediary chemicals before total mineralization. The toxicity and leaching potential of these metabolites is not well known. Lysimeter and field studies should be carried out.
Long-term impacts of heavy metals and organic pollutants, in particular on soil micro-organisms and fertility, are not well documented.
More data is needed concerning the ingestion and absorption levels of organic compounds and, to some extent, heavy metals, by animals.
There is also a lack of knowledge concerning the specific contribution of sewage sludge to pollutants’ transfers.
A survey of the organic pollutants’ levels in sewage sludge should be performed in the member states, in order to gain an accurate appreciation of their occurrence. This may only be possible if standard analytical methods are set and broadly accepted.
Available literature does not always enable a comparison between the different countries, as no common research protocol and no trans-national studies have been carried out.
More information is also needed concerning other routes for sludge recycling, such as land reclamation or use in forestry and silviculture. Research should be carried out to precisely identify the agricultural benefits of sewage sludge spreading and its environmental and sanitary impacts (especially concerning organic pollutants for which no data is currently available). Moreover, currently available information does not enable an assessment and comparison of the benefits and risk as regard the diversity of European forests.
Lastly, some interesting new technologies such as wet oxidation, pyrolysis and gasification have been developed. More information concerning their environmental impact and their application is needed. Tests have not always been carried out on sludge and this issue requires further documentation.”

Need for co-operative approach in Canada As in the USA, Europe and other countries, and because of the jurisdictional conflicts in Canada between the various levels of government on the various aspects of the wastewater industry, there is also the need for the federal government, and Environment Canada, as well as the municipal, provincial and territorial governments, as well as other stakeholders, to share the responsibility of promoting and defending the use of biosolids. In addition, they should participate in the establishment of an organization similar to the National Biosolids Partnership in the U.S. This organization might be called the Canadian Biosolids Partnership.

In Canada, municipalities have generally been left to their own resources to deal with biosolids. Municipalities are often told what they can’t do, but there is a clear lack of national direction, coordination, support and help from the provincial, territorial and federal governments as to what can be done with biosolids. While some governments may have fact sheets on biosolids, as well as guidelines for disposing of biosolids, these are not uniform in Canada, and consequently can be the basis for confusion in the industry.

Because of activists’ approaches, which are sometimes left unopposed and unchallenged by our regulators, and sometimes taken at face value, some municipalities may be faced with implementing processes that will serve political agendas which have absolutely no environmental benefit whatsoever. In other words, some municipalities may be forced to spend taxpayers’ money for no useful environmental purpose at all. There is a clear need for the various levels of governments to work together to ensure that the taxpayers’ environmental dollars are spent for environmentally beneficial purposes, and not merely for political, legal or activist purposes.

Ronald Leblanc is Chairman, Greater Moncton Sewerage Commission.
This article is adapted from his paper given at the First National Wastewater Forum 2005, Montreal.
Contact e-mail: gmscpcp@nbnet.nb.ca

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