By Nina Insinna
Summary: Industrial applications, and the foodservice industry in particular, present very unique and involved water pretreatment obstacles for operators and engineers. With growth projected comes an increase in grease, oil and other potential hazards in wastewater systems. One effective tool is a maintenance program that anticipates problems.
Unless you’re a centenarian, you probably don’t remember a time when it was considered safe to drink untreated water from open wells. Since the turn of the century, however, the world’s population has quadrupled to approximately 6 billion, creating a myriad of water and wastewater problems for government, industry and individuals.
Manufacturers use about 13 trillion gallons of water a year,1 not including the trillions used by the food service industry. The wastewater produced from these activities has proven to have a direct effect on freshwater quality. The ability of sewage treatment collection systems and plants to effectively handle and treat waste depends largely on the quality of influent to the collection system. This is paramount to the community’s health and economy. The burden of clean water, which was historically a governmental problem, is shifting partially onto the shoulders of wastewater producers.
Since the passage of the Clean Water Act in 1972, regulators have placed increasing pressure on industrial and commercial facilities to improve the quality of their wastewater. Fines now levied by various levels of government (largely in developed countries) amount to millions of dollars annually. Wastewater generators have a choice of either budgeting for the fines and surcharges and passing them along to their customers or taking a proactive stance by cleaning up their industrial-strength waste through best management practices (BMPs) and pretreatment technology.
Many food industry facilities have long been plagued with operational problems from drain lines that fail from stoppages, resulting in expensive downtime, repairs and clean-up activities. Grease and oil (G&O)—also referred to as fats, oils and grease (FOG)—have not only been the nemesis of the food industry, it has also had the same debilitating effect on the nation’s sewage collection systems. The Los Angeles Times reported in January, “More than 40 percent of (raw sewage) spills (in Orange County) occur because grease, mostly from food processing plants and restaurants, builds up in lines.”2
The food industry, whether processors or service, all face the same regulatory and operational problems. Even a temporary closure of an industrial facility affects more than its employees. For example, take a chicken processing facility, which can process hundreds of birds per minute. A line shut down for any length of time because of clogged drain lines can mean the difference between a profit or loss, and eventually affects the price to hotels, resorts, cafeterias, restaurants, supermarkets, convenience stores and the end consumer.
High strength wastewater often includes addressing defined levels of biochemical oxygen demand (BOD) and total suspended solids (TSS). Exceeding regulatory limits in these parameters doesn’t cause operational problems; however, it can result in fines and surcharges.
One company has developed unique solutions to this problem with source pretreatment as an integral element in their predictive maintenance program for clients’ under-slab drain lines. The president and CEO says, “Our efforts in keeping food processors and the food service industry in compliance with new, more stringent wastewater regulations has had a positive, direct effect on the bottom line, not to mention the pleasure of not having to deal with the objectionable situations caused by frequent backups.”
Here’s a rundown of the systematic program of waste reduction:
- Initial consultation and assessment of the client’s facility and operation by company consultants;
- Implementation of BMPs through staff education programs and proper disposal methodologies;
- Application of bioremediation systems: These systems use naturally occurring bacteria that are isolated and stress-trained to break down complex organic substances into simpler components (mostly carbon dioxide and water) and are harmless to the environment. As a result, drain lines are kept free flowing and the volume of pollutants entering the environment is reduced. This means fewer backups, overflows, failures and repairs due to grease throughout the entire wastewater system, protecting the facility’s collections as well as the public sewer; and
- Bi-weekly monitoring of grease interceptors and wastewater collection systems to detect and resolve problems before they occur as well as ongoing consultation with management.
This unique program has resulted in significant reductions of fines and surcharges, improved the quality of the workplace environment and enhanced relationships with government officials.
Tracking the results
Bioremediation differs from use of traditional mechanical methods and caustic chemicals in that it does no damage to the drainage infrastructure. By regularly introducing non-toxic and non-pathogenic microorganisms into the wastewater system, bioremediation has proven to be an effective method of reducing the buildup of fats, oils and grease. Below are three case studies implementing bioremediation as part of a predictive maintenance program with the following results:
1. A Florida dairy produces high butterfat sour cream, half-and-half and whipped toppings for institutional and industrial customers. Raw milk is trucked to the site and off-loaded into process tanks. Wastewater is generated during the cleaning of the tankers, lines and pumps. An automated “clean-in-place” (CIP) system is used to clean all tankers. The major components of the CIP consist of a pre-rinse, followed by hot alkaline surfactants and, finally, a sanitizer rinse. The majority of the BOD is contained in the pre-rinse. The CIP wastewater passes through a 500-gallon grease interceptor that reduces the BOD and the G&O in the wastewater. A second 1,000-gallon interceptor serves floor drains in the product packaging area. Due to housekeeping procedures and spill control, the second interceptor receives a minimal load of settleable solids. The average total daily wastewater flow is 3,000 gallons per day (gpd).
Result: BOD levels were reduced 39 percent and surcharge fees were reduced 43 percent (see Figures 1&2).
2. A poultry producer converted a North Carolina turkey processing plant to strictly chickens. In turn, chickens have more fat than turkeys. Hence, the retention ponds became dense with grease and the resulting noxious odors to nearby residents became unbearable. The city threatened to close the plant because of public outcry as well as the negative impact on the city’s collection and treatment systems. The average daily wastewater flow of the plant is 650,000 gpd.
Result: Within days of treatment the odor was under control. Within six months, an estimated 20 million pounds of FOG was biologically oxidized and the retention ponds were virtually free of grease (see Figures 3&4).
3. A Maryland food processing company receives corn syrup in traincar tankers that off-load into storage tanks. The syrup, which has an extremely high BOD content, is then pumped into truck tankers for distribution. Waste is generated during the cleaning of the tankers, lines and pumps. An automated CIP system is used to clean all tankers. The majority of the BOD is contained in the pre-rinse. All wastewater passes through a 20,000-gallon equalization tank where the pH is adjusted as necessary.
Result: BOD levels were reduced 57 percent and surcharge fees were reduced 76 percent (see Figure 3).
Maintenance equals profits
Since 1991, the company’s scope has grown from a “service provider” for restaurants to a provider of comprehensive solutions for clients that include industrial companies and water municipalities.
The value of a predictive maintenance program isn’t only solving problems, but also preventing them. This program is better than a static “insurance policy” because it addresses a dynamic and global concern. The availability of clean water begins with proper and effective pretreatment of wastewater.
The program described here is the right one at the right time. Producers are rushing to meet the increasing demands of the public. In 1998, each American spent $812 for food away from home. Between 1970 and 2001, restaurant-industry sales were set to post a compound annual growth rate of 7.5 percent. In 2001, the restaurant industry was expected to post its 10th consecutive year of real (inflation-adjusted) sales growth.3 The breadth of grease and oil problems in wastewater for commercial and industrial users cannot be effectively addressed by traditional methods. Predictive maintenance programs are a holistic approach that addresses problems not only at their source but before they occur.
- U.S. Bureau of Census data cited in U.S. Environmental Protection Agency publication, Liquid Assets, p.10.
- Cone, Marla, “EPA Sues to Demand that LA Prevent Spill from Sewer Lines,” Los Angeles Times, Jan. 9, 2001.
- National Restaurant Association, FAQ, June 6, 2001.
About the author
Nina Insinna is a development consultant with Environmental Biotech Inc. (EBI), a 10-year-old industrial biotech firm. EBI has been selected by the USEPA to co-author and present the official course on “Grease Pretreatment for Wastewater Officials.” EBI also presents a Grease Summit, which is an NEHA-accredited course. For further information, contact the Global Development Department at (800) 314-6263, (941) 359-9744 (fax) or website: http://www.environmentalbiotech.com.
A Greasy Subject—CEUs for G&O Remediation
One of the difficulties in addressing the nation’s “grease problem” is a lack of formal education for engineers and wastewater professionals in dealing with grease-laden wastewater. This need for education has been addressed through a “Grease Summit.” The summit fulfills three of the five areas of emphasis—Registered Environmental Health Specialist, Certified Environmental Health Technician and Registered Hazardous Substances Professional. This course also satisfies requirements for continuing education units (CEUs) or contact hours varying by state for professions such as registered environmental specialist, environmental health technician, and registered hazardous substances professional. The course covers the technical, practical and legal aspects of grease and oil (G&O) contamination and fosters a workable understanding that allows problematic wastewater dischargers to help themselves as well as their communities.