Management of Septage and Sewage Sludges
Contents |
Background
In the fall of 2000, the ECO received an application for review under the EBR that raised concerns about the practice of applying wastes from septic tanks and portable toilets to farmland. The technical term for these wastes is “septage” or “hauled sewage,” because they are pumped out and hauled by truck. The applicants emphasized the need for a consistent policy and enforceable regulations, and they requested that the spreading of these wastes on farmland be stopped immediately until studies could be done on its safety for public health and the environment. The Ministry of the Environment decided to deny this request, stating that the ministry was already carrying out an internal review of the province’s septage-spreading program. Although MOE did not advise the applicants when this review might be completed, the ministry did commit to posting any resulting environmentally significant proposals on the Environmental Registry. Several months after the application was denied, MOE informed the ECO that it had launched an internal review of policies regarding the land application of sewage sludge, septage and pulp and paper sludge, with a formal EBR consultation – a notice posted on the Environmental Registry – planned for spring and summer of 2001. (For a full description of this EBR application, see Section 5 of the Supplement to the annual report.)
On March 5, 2001, the ECO received another EBR application for review, dealing with sewage sludge. Sewage sludge is the settled residue from municipal sewage treatment plants. In this case, the applicants asked that MOE approvals for spreading sewage sludge on land be posted for public comment on the Environmental Registry. Currently such approvals are not subject to the EBR because MOE did not include them in its list of classified instruments under the EBR. (The ECO will report on the outcome of this application in our 2001/2002 annual report.)
Weak Enforcement
The ECO has received a wide range of complaints from individuals, citizens’ groups and farmers about MOE’s enforcement of rules governing the land application of both sewage sludges and septage. There are also complaints that the rules themselves are not strong enough. The ECO has heard complaints asserting that MOE does not require landowner approval for spreading of sewage sludge, does not adequately monitor volumes of waste being spread onto sites, does not hold back sludges from land spreading while their quality is being tested, does not enforce minimum digestion times, does not deal firmly with persistent violators, and is reluctant and unhelpful about carrying out groundwater tests when residents complain of well water contamination.
In one case, EBR applicants say that some MOE staff do not consider it within their mandate to enforce guidelines outlined in certificates of approval (C of A) for septage spreading. They also allege that MOE repeatedly renewed the C of A for a septage-spreading site without adequately considering nearby new homes and without having full records of waste quantities being disposed there.
In another recent case, residents allege that MOE did not inspect a septage-spreading site before issuing an approval. They state that only after a large volume of septage had been spread onto the site over a six-week period, MOE sent a hydrogeologist to the site, who determined that it was unsuitable, and that the permit should be revoked. These residents allege that the incident has caused bacterial contamination of their wells.
The ECO has in past years already reported on some aspects of the land spreading of human, animal and other organic wastes. The ECO’s 1999/2000 annual report described the environmental impacts of the huge manure volumes produced by new intensive farm operations. Similarly, the ECO’s 1998 annual report described how the land spreading of pulp mill wastes is regulated. This discussion focuses on septage and municipal sewage sludge. Other categories of organic wastes such as abattoir wastes, fats, oils and greases are also spread onto farmlands in Ontario, but are not specifically addressed in the discussion below.
Sewage Sludge Handling and Environmental Impacts
Municipal sewage treatment plants are designed to produce a liquid effluent that is clean enough to meet rules for discharging back into lakes and rivers. At the primary and secondary states of treatment, solid materials are settled out from the process. Sewage treatment plants treat these solids first by bacterial decomposition, through either aerobic or anaerobic digestion. The resulting material is called stabilized sewage sludge. The stabilizing process substantially reduces pathogen numbers (viruses, bacteria, fungi and protozoa) in sewage sludge, but does not eliminate them.
Approximately 7.5 million cubic metres of stabilized sewage sludge (often also called biosolids) are produced by Ontario municipalities each year, and they must be disposed of somehow. In 1994, MOE estimated that approximately 55 per cent of this sewage sludge went to landfills, 27 per cent was incinerated, and 18 per cent was applied to agricultural lands. Land application is becoming more widespread in Ontario, although current estimates are not available. One reason for the increase in land application is that it is cheaper. For example, Durham Region in southern Ontario has reported that incineration of its sludge is 15 per cent more expensive than land application. The air pollution and odour complaints associated with sludge incineration have also encouraged cities to make the shift to land spreading. The City of Toronto, which produces 80,000 tonnes of sewage sludge a year, is working toward phasing out incineration, and in 1999 spread about one-third of its sludge on farmlands.
Land application of sewage sludge is not only cheaper; when carefully applied, sludge can also provide some fertilizing and soil conditioning values. According to the Ontario Ministry of Agriculture, Food and Rural Affairs, farmers who spread sewage sludge on their lands can save about $100 an acre in fertilizer costs for nitrogen and phosphorus. However, farmers need to consider many factors in order to use these nutrients to their best effect and to minimize runoff into groundwater, streams and rivers. Farmers also need accurate and up-to-date information on the nutrient content of both the sludge and the receiving soil in order to allow them to calculate the agronomic application rate, i.e, the optimal loading of nutrients that will meet crop needs without exceeding what the crops can absorb.
To be useful to crops, sludge must also be applied at the right time of year. For example, phosphorus must be available to seeds at the time of germination, and nitrogen, if applied in the fall, can interfere with the normal dormancy process for overwintering crops. The windows of opportunity for sludge spreading are further narrowed to times when fields are bare, to avoid damaging crops with heavy equipment. But early spring and late fall are also often the wettest seasons, when rains may wash freshly applied sludge into waterways, and when wet soils may be damaged by compaction from heavy truck traffic. Significant environmental damage can occur when sewage sludge is washed into waterways. The predominant risk is that groundwater, creeks and rivers can be polluted by phosphorus and nitrogen, leading to algal blooms, oxygen depletion and fish kills. Pathogens are also a concern, since they may migrate into groundwater or surface water and contaminate drinking water supplies. There are also concerns about the environmental impacts of contaminants in sewage sludge, particularly heavy metals and industrial organic chemicals. The most common fate of hazardous and industrial wastes is to be poured into municipal sewer systems, and to end up in sewage treatment plants.
Close to 400,000 tonnes of such wastes are disposed of this way in Ontario annually, according to a 1991 estimate. To address this concern, OMAFRA recommends that sewage sludge should not be used on crops with leaves or roots that will be used for human consumption, and would be best used on seed or grain crops which are less likely to accumulate heavy metals. As well, researchers have begun to investigate the fates of pharmaceuticals such as antibiotics and a wide range of endocrine disrupting substances after they enter municipal sewer systems.
Septage Handling and Environmental Impacts
Septage or “hauled sewage” includes waste pumped from domestic septic tanks when they are periodically cleaned, as well as holding tank waste and waste from portable toilets. This material is primarily human faeces and other toilet waste, as well as waste from showers, bathtubs, kitchen and laundry sinks.
MOE estimates that there are over 1.2 million private sewage systems in Ontario, most of which are septic tanks, serving more than 2.5 million people. According to MOE estimates, 1.2 million to 1.75 million cubic metres of hauled sewage are pumped from these systems each year, although some industry estimates are higher. Ontario has approximately 1,500 to 1,700 sewage hauling companies operating, and most of these are small, one-truck operations.
The disposal options for Ontario sewage haulers include either dumping into sewage treatment plants or sewage lagoons, or land application. MOE does not provide estimates on how widespread each of these disposal options are, but according to one industry view, the vast majority of hauled sewage in Ontario is applied to farmland, because very few sewage treatment plants or sewage lagoons are able to accept the added volume. Many sewage treatment plants in Ontario are aging, and with population growth, are also reaching their operating capacity. MOE recommends that sewage treatment plants operating at or near their hydraulic or organic capacity should not accept hauled sewage. High treatment and trucking costs also discourage the use of sewage treatment plants.
Once spread on land, the potential environmental impacts of septage and municipal sewage sludge are in many ways similar. Both types of waste contain nutrients that may contaminate waterways if they are not taken up by crops, and both may contain trace contaminants such as heavy metals. But septage is likely to have much higher concentrations of live pathogens such as bacteria and viruses than municipal sewage sludge. This is because MOE does not require any treatment of septage to cut down pathogen levels before land application. Septage can include waste from portable toilets, and their disinfectant chemicals can also be an environmental concern.
Although municipal sewage sludge and septage are similar materials with similar environmental impacts, they are regulated very differently in Ontario.
Regulation of Land Spreading of Septage
In April 1998, the regulation of septic systems was transferred from the Ministry of the Environment to the Ministry of Municipal Affairs and Housing, which administers the Building Code Act. MOE retained the oversight of sewage haulers, however, and made a number of changes, mainly house-keeping, to the pertinent regulatory system, but did not substantially change its content. Under Part V of the Environmental Protection Act, sewage haulers must now have a certificate of approval for a Hauled Sewage Waste System. This C of A covers the business and equipment, the septage disposal sites, and how the system is operated. Haulers under the pre-1998 system had to provide the ministry with some basic information in order to convert their old licences to the new certificates of approval. Haulers were also able to continue using their old disposal sites, provided that they met certain conditions. Under the new regulatory structure, septage disposal sites, once they are approved by the local MOE office, become part of a “schedule” attached to the certificate of approval.
Sewage haulers who request MOE approval for a new disposal site must pay a $100 fee, fill out a three-page form and provide a sketch of the site showing relevant features, setback areas and spreading locations. Since these approvals are not classified as instruments under the EBR, MOE is not required to post a proposal notice for public comment on the Environmental Registry. In some cases, MOE staff may visit the site before they issue an approval. No testing of soils or wastes is required.
A regulation under the Environmental Protection Act states that septage shall not be applied in a manner that permits it to enter a watercourse or drainage ditch, or results in runoff leaving the site.
The same regulation also requires that the owner of the site provide written authorization for the spreading. MOE has established minimum setback guidelines that state that septage storage or spreading must be a minimum of 90 metres from water wells, and at least 120 metres from surface waters. These setbacks may be reduced by 50 per cent in some cases. According to the guidelines, the slope of the land should not be greater than 9 per cent, and spreading during periods when ground is frozen or snow-covered must be approved by an MOE Director on a site-by-site basis.
According to media reports in February 2001, MOE began prohibiting winter spreading of septage in early 2001. However, this change was not posted on the Registry. The guidelines also set restrictions (subject to amendments by an MOE Director) on future uses of the land. For example, livestock should not graze on a site within six months of septage application, and feed crops should not be harvested within three weeks of application.
MOE District staff also rely on an internal document entitled “Former Chapter 13” to assess applications for septage disposal. The document states that septage may be either spread onto the surface of soil or incorporated into soil by mechanical injection or a similar method. Depositing septage into old sand or gravel pits, especially in winter, is also considered an option. While the document recommends spreading the septage as evenly as possible, it acknowledges that varying truck speed may be the only means of doing this. It also recommends that “if possible, avoid application within 24 hours of heavy rains or just before rain.” A general rule of thumb for nitrogen is also offered: “If the amount of hauled sewage applied each year is restricted to one million litres per hectare (or 100L/square metre ) the nitrogen load should not exceed crop needs. This loading should also provide reasonable protection to the ground water.”
Regulation of Land Spreading of Sewage Sludge
Land application of municipal sewage sludge is also regulated under Part V of Ontario’s Environmental Protection Act, and O. Reg. 347. Municipalities or contractors must apply to MOE for a certificate of approval for an “organic soil conditioning site.” These Cs of A typically contain very site-specific conditions and also require compliance with a short list of general standards set out in O.Reg.347. (A separate C of A is required for storage facilities for sewage sludge.) Before issuing a C of A, ministry staff inspect proposed sites for conformity both with the regulation and with a lengthy document entitled Guidelines for the Utilization of Biosolids and Other Wastes on Agricultural Land (the Guidelines). But it is not clear whether MOE always includes a condition requiring ongoing compliance with the Guidelines in each C of A. In the absence of such a condition, the Guidelines are not enforceable.
The Guidelines are a mix of many recommendations and a few requirements, covering testing of soils and sludges, spreading rates, separation distances from surface water, residences and wells, recordkeeping requirements and the responsibilities of spreading operators and farmers. The Guidelines note that all sewage sludge must be stabilized before being spread, and that the number of pathogenic organisms must be reduced “to an acceptable level.” They recommend caution when spreading wastes onto snow-covered or frozen ground, but allow it on flat fields, provided that the risks of runoff are minimal. The Guidelines say that “waste materials containing high concentrations of industrial organic chemicals will not receive approval for land application,” but don’t define “high concentrations” nor do they require testing for these parameters.
MOE provides no opportunity for public consultation on approvals for land spreading of sewage sludge, since they are not classified as instruments under the EBR. Thus, there is no information posted on the Environmental Registry, no public comment opportunity, and no opportunity for the public to request either leave to appeal or a review under the EBR, once an approval is issued.
In November 2000, MOE responded to intense public concern and allowed a one-day public comment period on a major approval for sludge spreading by Azurix North America – despite the fact that this approval is for City of Toronto sludge, and is expected to have implications for numerous municipalities serviced by the company across Ontario. Nor was the province’s own Biosolids Utilization Committee consulted on the approval. One unexpected outcome of this approval is that it formally removed the opportunity for other municipalities to reject Toronto sludge for spreading on their lands.
In late 1998, MOE proposed a major streamlining of many types of approvals, including approvals for land spreading of sewage sludges, by developing Standardized Approval Regulations (SARs). Under this approach, proponents would have to send a start-up notice to the ministry along with certain background information and a fee, and would have to comply with the SAR’s provisions, but would be otherwise exempt from the approvals system. Presumably, the ministry would no longer impose site-specific conditions, since the SAR would contain uniform, province-wide requirements. The ministry did publish a draft SAR for land spreading of sewage sludges, but has not provided recent updates, and it is not clear whether the ministry still plans to proceed with this approach.
Inadequacies in Existing Rules
The ECO’s review of existing policies and regulations for the land spreading of sewage sludge and septage has concluded that they are not adequate to protect the environment, even if they were consistently and firmly enforced. Ontario’s existing rules for the land spreading of sludge and septage are not founded on the need to protect ecosystems, and they also fail to provide opportunities for the public to be involved in environmentally significant decisions. A number of major weaknesses, common to both sets of rules, are outlined on Problems with Ontario's Existing Rules for Sewage and Septage Spreading. As well, even though septage presents a greater risk of introducing pathogens into the environment, Ontario’s septage spreading rules are weaker in the following ways:
- There is no requirement in Ontario that septage be stabilized to reduce pathogens prior to land spreading, even though Ontario’s Biosolids Utilization Committee recommended this several years ago.
- There is no requirement that septage spreading be of benefit to soil and crops. In contrast, Ontario guidelines for land spreading of municipal sewage sludges do state that “these materials must be of benefit to crop production or soil health and not degrade the natural environment.”
- There is no requirement for adequate septage storage. The times when septage can safely be spread are limited by weather conditions and crop needs. But when storage facilities fill up, operators face great pressure to spread septage, even if fields are wet, frozen or otherwise unsuitable. In contrast, Ontario guidelines for land spreading of municipal sewage sludges do state that sufficient storage must be available, and that a minimum of six months of storage will normally be adequate.
- There is no MOE or industry-funded research into better environmental management of septage.
- There is no certainty that MOE staff inspect sites before approving them.
Conclusions
The ECO’s review has found significant weaknesses in the current legislation and practices governing the land spreading of sludges and septage. There are evident problems in both the regulatory regime and in the way the existing rules are being enforced. MOE appears to have recognized this, and has launched an internal review of policies regarding the land application of sewage biosolids, septage, and pulp and paper sludge. MOE has informed the ECO that OMAFRA and MMAH are involved in the process, that pre-consultations with key stakeholders have begun, and that formal consultations through the EBR process will occur in the late spring and early summer of 2001.
MOE should ensure that its policy review of these matters addresses the need for ecosystem protection and that approaches such as nutrient management planning and protection of groundwater recharge areas are considered. MOE should also address the need for the public to have a voice in environmentally significant decisions, both at the broad policy level and on more local site-by-site decisions. To allow for informed public comment, MOE should provide current information on existing trends and patterns of sludge and septage management in Ontario, as well as current information on environmental impacts. There have been recent developments on this issue. For ministry comments, see pages 190-192.
| Recommendation 3:
The ECO recommends that MOE and OMAFRA ensure that the new legislation and policies for sewage sludge and septage address the need for overall ecosystem protection, as well as protection of groundwater recharge areas. |
| This is an article from the 2000/01 Annual Report to the Legislature from the Environmental Commissioner of Ontario. |
Citing This Article
Environmental Commissioner of Ontario. 2001. "Management of Septage and Sewage Sludges." Having Regard, ECO Annual Report, 2000-01. Toronto, ON : Environmental Commissioner of Ontario. 48-56.
