Sludge without liability: Minimizing the risks
Wastewater is discharged daily from private residences and industrial facilities all across the nation. The vast majority of these discharges are routed to publicly owned treatment works (POTWs) prior to discharge into waters in the United States. In addition, POTWs typically receive a certain amount of runoff from various other sources.
For the most part, the treatment performed by a POTW results in effluent discharge and residual material. It is this residual material, which can have a number of different biological and chemical constituents, that is commonly referred to as sewage sludge.
Quite often, these constituents include volatile organic compounds, organic solids, disease-causing organisms, heavy metals, toxic organic chemicals, household chemicals and pesticides. Importantly, POTWs have been required to implement greater levels of treatment to wastewater prior to discharge.
Each time treatment levels increase, so, too, does the amount of sewage sludge generated as a result of the treatment process. In the United States, the amount of sludge generated by municipalities has almost doubled since 1972.
Currently, municipalities generate in excess of 5.3 million dry metric tons of sewage sludge per year, and, as a result, proper management is becoming an increasingly important concern for local government officials.
On Feb. 19, 1993, EPA issued its “Standards for the Use or Disposal of Sewage Sludge,” otherwise known as the Part 503 Rule, to regulate the management of sludge. Under the Clean Water Act, the Resource Conservation and Recovery Act and the Clear Air Act, POTWs are allowed a number of different sludge management options.
Generally, sewage sludge management alternatives available to most municipalities include incineration, co-disposal with municipal solid waste, surface disposal in sludge-only facilities or monofills, land application and using sewage sludge as feedstock in the production of fertilizers and as soil conditioners. Liability, of course, is a problem with any management system. It can, however, be reduced.
Incineration
Incineration destroys the organic pollutants contained in, and reduces the volume of, sewage sludge. EPA estimates that approximately 16 percent of the sludge generated by POTWs is incinerated.
As such, incineration greatly reduces the amount of sewage sludge that must be landfilled. But if a municipality generates large volumes of sewage sludge, incineration may become a costly management option.
If the POTW is operating the incinerator, the permit issued will contain all of the Part 503 requirements: “For the incineration of sewage sludge, municipalities must take sufficient measures to control the emissions from sewage sludge incinerators. Otherwise, particulates, heavy metals, toxic organic compounds and hydrocarbons will add to a community’s air pollution problems.”
As with other sludge management options, incineration can carry potential liability, However, municipalities can transfer liability by using the services of an independent company and refraining from operating incinerators themselves.
Many cities do not have the expertise on staff to effectively operate an incinerator, while private operators are in that business specifically. The operator of a sludge incinerator must ensure that sludge fed into the incinerator does not contain certain pollutants in excess of allowable limits. In particular, incinerator operators are authorized to accept only sewage sludge containing acceptable levels of lead, arsenic, cadmium, chromium and nickel.
Similarly, incinerator operators must ensure that the incineration of sewage sludge does not violate certain emission standards and limitations. For the most part, the firing of sewage sludge may not violate the requirements in the National Emission Standard for beryllium and mercury.
In addition, incinerator operators are required to monitor and control the total hydrocarbons concentration in the exit gas from the incinerator. Operators must ensure that the monthly average concentration for total hydrocarbons in the exit gas, corrected for zero-percent moisture, does not exceed 100-parts-per-million on a volumetric basis.
Moreover, operating incinerators requires monitoring and recordkeeping designed to evaluate the incinerator’s compliance with all applicable pollutant limits, emission limits, operational standards and management practices.
Therefore, if the municipality does decide to operate the incinerator itself, it will want to monitor pollutant levels carefully.
Land Application
Land application for beneficial use is one of the more common methods of managing sewage sludge generated by POTWs. Sludge often contains nutrients and other properties that are useful as fertilizers and soil conditioners. As a result, sludge has been used on agricultural lands, forests, landscaping projects, strip-mine reclamation projects and other situations where improvements in land productivity have been sought.
At the time of the enactment of the Part 503 Rule, EPA estimated that approximately one-third of all sewage sludge generated in the United States was managed via land application. Under a land application situation, POTWs generating sludge are required to obtain a permit.
The contract sludge hauler or land application professional hired by the POTW, on the other hand, is not required to apply for permits. The Part 503 Rule states: “If the treatment works uses a commercial sewage sludge applier that does not change the quality of the sewage sludge for land application, the treatment works will still be held accountable, and through its permit for the commercial applier’s compliance, since the Agency considers that the treatment works still retains control over the quality of the sewage sludge. In this case, as the generator of sewage sludge, the treatment works cannot limit its responsibility for the use and disposal of the sewage sludge in compliance with the standards merely by transferring the sludge to a commercial applier.”
Therefore, municipalities may want to monitor contract haulers and/or land appliers carefully.
Negligence by contractors that do not significantly improve the quality of sludge prior to application may create compliance problems. A number of management practices can be followed in the typical land application situation.
First, municipalities will want to make sure contractors are not applying sludge to flooded, frozen or snow-covered land in such a way that the sludge enters wetlands or other waters. In fact, most sludge may only be land applied to sites located 10 meters or more away from any nearby water source.
In addition, sludge may be applied only at a rate equal to or less than the agronomic rate of nitrogen for the crop to be grown. The agronomic rate is a rate that is designed to provide the amount of nitrogen needed to obtain a desired yield, yet still limit the amount of nitrogen that will enter the groundwater.
Sludge may not be applied to any area that harms or contributes to the harm of a threatened or endangered species or causes the destruction or modification of the species’ critical habitat — any place where a threatened or endangered species lives during any part of its life.
In land application, as well as with other forms of disposal, tort liability can become a risk to municipalities primarily because of the potential for surface and groundwater impact, contaminant migration and odor. Yet, municipalities choosing land application can take steps to avoid liability. For instance, municipalities can request indemnification and hold harmless agreements from contract haulers and land appliers.
In addition, municipalities can require haulers and land appliers to demonstrate that acceptable insurance has been procured for the project, and they can even request that the city or county be named as additional insureds on all pertinent insurance policies.
These steps, coupled with appropriate diligence in selecting contract haulers and land appliers, can substantially minimize the liability risks in land application situations.
Products
Reuse by blending sewage sludge with other materials to produce products like fertilizer and soil conditioners is another effective method of sludge disposal.
Specifically, the Part 503 Rule divides sludge (commonly referred to as biosolids) and sludge-derived products into four categories: exceptional quality (EQ) biosolids, pollutant concentration (PC) biosolids, cumulative pollutant loading rate (CPLR) biosolids and annual pollutant loading rate (APLR) biosolids.
Initially, EPA divides sludge and sludge-derived products into categories by examining pollutant concentrations. For the most part, the pollutants regulated under the Part 503 Rule are metals, six of which are metals that are commonly regulated under RCRA’s hazardous waste rules and regulations. EPA considers the levels of pathogens present in the sludge or sludge-derived products. Class A products are ones where selected pathogens are not present above detectable levels and when fecal coliform levels do not exceed 1,000-per-gram of total solids.
Class B products require pathogen reduction of more than 90 percent and fecal coliform below 2 million per gram of total solids and require restricted access management practices. Products are evaluated in light of certain vector attraction reduction requirements.
Vectors, which include flies, mosquitoes, fleas, rodents and birds, are those creatures that are typically responsible for transmitting pathogens to humans and other susceptible hosts. The vector attraction reduction requirements contained in the Part 503 Rule are aimed at reducing the attractiveness of products to vectors. This, in turn, reduces the potential for transmitting diseases from pathogens to humans. In-vessel and windrow composting and production of biosolid pellets and alkaline stabilized materials are several methods available.
Clearly, the most benign products are those which are classified as EQ biosolids because they meet the most stringent pollutant limits, pathogen requirements and vector attraction reduction requirements. Once all pertinent EQ requirements are met, EQ biosolids are no longer regulated under the Part 503 Rule and may be applied as freely as any other fertilizer or soil amendment. Therefore, EQ biosolids would not only pose the lowest risk to human health and the environment but the lowest risk of municipal liability as well.
As to liability under the Comprehensive Environmental Response, Compensation and Liability Act, EPA asserts that if the placement of sludge on land were considered to be (1) the “normal application of fertilizer” under CERCLA or (2) a “federally permitted release,” CERCLA liability would not result. Presumably, however, the disposal of sewage sludge in a solid waste landfill, monofill or surface disposal site would not qualify as a “normal application of fertilizer” under CERCLA. In addition, if any of the requirements contained in a permit for a monofill or other surface disposal site, or a permit authorizing the land application of sewage sludge, were violated, it appears that a release would not be considered “federally permitted.”
That being the case, EPA’s brief CERCLA liability discussion in the preamble to the Part 503 Rule is not a complete analysis of the potential for liability in sewage sludge disposal and/or land application situations. Despite EPA’s assertions to the contrary, the potential for CERCLA liability is a possibility in certain circumstances. In any event, as an analysis of the preamble to the Part 503 Rule reveals, EPA strongly encourages the beneficial reuse of sewage sludge by reusing it in the production of an EQ biosolid product, municipalities can greatly reduce their potential liability.
As a result, making a product or EQ biosolid can help municipalities meet their sludge management obligations, while giving back to the environment as well.
Shane Farolino practices environmental law, with Roetzel & Andress, Akron, Ohio.
Sewer pipe allows city to outfox problems
Bakersfield, Calif., wanted to open the rugged foothills northeast of the city for residential development. The area had been annexed into the city in the 1970s, but growth was slow. To speed up this growth, municipal officials needed to provide sewer service to the new development in the most economical way.
Developing a community leachfield system, constructing a package treatment plant or running a new sewer line to the development from an existing treatment facility were three options considered by Porter-Robertson Engineers, a local consulting firm. Although, the up-front cost of running the line was greater than the other options, officials determined that, in the long run, it was the most cost-effective method.
The projected fees from the community leach system and the cost of the package treatment facility would have been far in excess of the projected $700 per-dwelling fee to connect to a new sewer line.
As Speiss Construction, Santa Maria, Calif., worked on the planned route of the new line, Jim Movias, principal planner with the Bakersfield Development Services Department, put the finishing touches on a Habitat Conservation Plan, designed to protect the area’s natural habitat and meet the requirements of state and federal endangered species acts. A biostudy conducted to identify wildlife within the proposed pipe corridor, revealed a number of San Joaquin kit fox dens within the path.
To avoid disturbing the dens, which were located in a fairly deep ravine directly along the pipe route, pipe was moved 300 feet up the hill.
The move increased the burial depth of the pipe to approximately 37 feet, necessitating stacked trenchboxes. In addition to the challenges of working at a lower depth, construction crews had to adapt to a variety of soil conditions, including cobble boulders, blue clay, silt and sand, that make trench walls unpredictable.
The quality of construction was monitored, and soil samples were sent to an independent lab for testing. Bedding consisted of screened native material.
Ninety percent compaction was achieved in the pipe zone; 85 percent was achieved one foot above the pipe to the surface. A go-no-go steel mandrel was pulled through the line, which passed a low-pressure air test the first time — results were within the 5 percent deflection specification.
According to the city, the Lamson Vinyl PVC pipe used for the project has been in service for over one year and is performing to standard without leakage. Since completion of the line, a new magnet school has been constructed in the area, and residential development is moving at a rapid pace.
Peer review team looks at facility’s procedures
With so many people living in Boston and its suburbs, it is not surprising that Boston Harbor became one of the most polluted bodies of water in the nation.
However, with the help of wastewater treatment plants that run at capacity levels, that is changing. The Deer Island wastewater facility treats up to 1.2 billion gallons of wastewater per day from the Boston metropolitan area and 43 nearby communities. The plant’s primary treatment process was completed in 1995, and the secondary treatment process was scheduled for completion one year later.
At that point, John Fitzgerald, sewage division director, decided to examine the staffing needs of the facility, to ensure the plant could handle the heavy volume. An independent review of Deer Island staffing assumptions and levels was conducted. The staff assembled a peer review team of 11 members from the cities of Newark, N.J.; San Francisco; Chicago; Los Angeles; St. Paul, Minn.; and Seattle to provide a real-world review of the entire plant operation and make practical recommendations on staffing levels. The team consisted of managers from six large wastewater treatment facilities, Smith Clup Consulting, Seattle, Wash. and GRV Consulting, Owasso, Okla.
The Massachusetts Water Resources Authority (MWRA) staff sent background information to each team member for review. The team was asked to spend five days on site interacting with the staff and viewing the day-to-day operations of the facility. The MWRA department managers made presentations to the team explaining the authority’s needs, its current operations and its view of the future.
Team members were allowed to question each manager as to the specifics of his or her department, and this information was compared with the operations of the peer cities. The team met daily to review and analyze the information in order to reach a preliminary consensus on each item. If the team had questions, it was allowed to recall individual managers or staff, and MWRA assigned an employee to assist in answering questions, providing background information and locating key personnel.
The report explained how workers could perform better if given more training and support and offered recommendations that would help open communications between maintenance personnel and operation personnel. All the recommendations were made with an eye toward finding ways for the facility to compete with private industry. The team recommended the plant:
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focus management and staff on teamwork and cross-functional flexibility;
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change work rules that limit the flexibility of operations and maintenance employees;
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establish operation and maintenance teams to clearly define maintenance priorities;
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create a joint labor and management team to achieve staffing goals;
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explore ways to further automate the plant; and
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use outside support to meet the demands of startup.
The findings were accepted by the group because each department was given a chance to explain its needs, voice its concerns and see how utilities of similar size approach the same tasks.
MWRA’s investment in the peer review concept has returned enormous benefits, including improved communications between management and labor, a spirit of cooperation across the authority, increased staff productivity and resources for future support and cost savings.
“We constantly evaluate our internal management structure to improve efficiency,” says Douglas MacDonald, executive director of MWRA. “Conducting outside peer reviews on a periodic basis is an important part of this effort.”