Storm waters discharged from municipalities and industrial plants are regulated by the USEPA. Under the Phase 1 program, there are eleven categories of facilities that require NPDES permits for storm water discharges. Beverage plants are not included in this program unless there is a potential for storm water discharge of materials, such as sugar, high fructose corn syrup, chlorine, acid, caustic, beverages from can crushing, oils, paints, etc.

If beverage plants can answer NO to a number of questions relating to the manner in which raw materials, finished products and chemicals are handled and stored, they can obtain a “Conditional No Exposure Exclusion for Industrial Activity”. NO means that there is no way possible for these materials to end up in the runoff or storm waters.

There is a form that can be downloaded from the USEPA WebPages and submitted either to the state environmental agency or to the local municipality.

All municipalities are regulated under the Storm Water Regulations and designated as MS4 (municipal separate storm sewer system) and consist of the entire storm conveyance system, including storm sewers, ditches, and retention ponds, etc. Large and medium MS4s were regulated under Phase 1 regulations in 1987, with small MS4s being regulated under Phase 2 regulations in 2003. What this means to beverage plants is that the local municipality probably administers the storm water process.

First, plants should file a “Conditional No Exposure Exclusion for Industrial Activity” with the local municipality. Verify this in advance since there are some areas where storm water regulations are being enforced by the state and possibly the EPA.

Second, plants should investigate discharging some of the clean water streams to the storm sewer. These include, settled filter backwash water, non-contact cooling water and possibly, reject water from membrane treatment, e.g. reverse osmosis. Significant sewer charges can be avoided by reducing flow to the sewer.

Regardless of the source of water, bottling plants employ a wide range of water treatment processes to obtain quality standards. Each of these processes generates a waste stream that must be managed.

Lime softening processes utilize the addition of calcium hydroxide (lime), sodium carbonate (soda ash) and ferrous sulfate (iron sulfate). The addition of these chemicals results in the precipitation of the hardness ions, calcium and magnesium, and the alkalinity ions, bicarbonate and carbonate. The lime softening processes generate a large volume of solids, consisting of calcium carbonate, magnesium hydroxide and ferric hydroxide. For each pound of hardness treated, this process generates approximately two pounds of dry solids.

Membrane processes, such as reverse osmosis, generate reject streams consisting of 10% to 30% of the original raw water flow. The reject stream contains concentrated salts and solids plus chemicals used to prevent precipitation of scaling chemicals, such as acids and chelants. Assuming a permeate or product flow of 400,000 gpd, the reject flow could vary from 44,000 gpd to 171,000 gpd.

Depending on the TDS (total dissolved solids), the pH, COD (chemical oxygen demand) and oil concentrations, it may be possible to discharge the reject stream to the storm sewer (Section 1.3).

Softeners, specific ion resin beds and de-alkalizers all employ ion-exchange resins to exchange one ion for another. As the water passes through the bed, ions in solution such as the hardness ions, calcium and magnesium, for sodium and specific ions such as nitrate and fluoride ions are exchanged for chloride ions.

Regeneration produces a waste stream consisting of high levels of acids, caustic or salts.

pH All permits will require the wastewater pH to be in the neutral range of 6 to 9. Some municipal permits will allow a wider pH range, but that is unusual.

To accurately measure wastewater discharge from a beverage plant, it is necessary to have a sampling station where the flow can be accurately measured and flow- proportioned samples can be obtained. Most municipalities require the sampling station to be located on the process sewer where no sanitary wastewaters are included. 4.2.1 Flow Measurement Sewer flows are normally measured in a free flowing sewer with a flume inserted into a manhole, where the height of the water flow indicates the flow. There are two principal flumes that can be used. A Parshall Flume (Figure 2.0) is in the shape of a venturi and is normally located in an open channel or constructed as part of a flow-monitoring manhole. To measure flow,the height of the water at the entrance to the flume is measured.

There are many factors that affect the volume and strength (BOD concentrations) of wastewaters discharged from beverage plants. It is a known fact that well run plants generate less waste than poorly run plants. Management attitude and control are the primary factors. The amount of wastes is dependent on how much of the syrup is converted into a quality product.

Our measure of plant efficiency used to calculate plant efficiency is to calculate the daily production of BOD 5 in terms of pounds or kilograms. We know the BOD 5 concentrations of products (Section 3.1.4) and if we know the volume of production and the packages, we can calculate the total amount BOD5 produced by the plant.

• Sum up the monthly production and assume 25 days per month;

• Calculate daily production in terms of cubic meters;

• Assume regular beverage is 85 kilograms of BOD5 per cubic meter (kg/m3);

• Calculate daily production in terms of kg/day;

• Analyze available wastewater data to determine average flow and BOD5 concentrations;

• Calculate kg/day of BOD5 discharged;

• Divide kg/day BOD5 by kg o f product per day; and

• % Loss represents the BOD5 down the sewer as compared to BOD5 processed through the plant.

The primary sources of wastewater are:

• Syrup Room;

• Filling Operation and Change-Overs;

• Water Treatment;

• 5-Gal Pre/Post-Mix Cleaning and Filling;

• Bag-In-Box (BIB);

• Can Crushing;

• Sanitation; and

• Hi-Fills/Lo-Fills, Off-Spec Beverages.

The Syrup Room represents a potential of 50% of all BOD discharged to the sewer. This is due to the concentration of the sugar in the syrup, which may be as high as 60% of the liquid volume. BOD is discharged from the Syrup Room from leaks, drips and during CIP operations. It has been documented that 60% of the total BOD is washed from a syrup tank during the first 11⁄2 minutes of the first rinse.

Leaks and drips are the major sources of BOD during filling operations. This is generally due to old equipment or poor maintenance. Leaking seals, joints, gaskets, etc. all contribute. Foaming, due to warm product, is also a potential problem. Frequent Change-Overs will greatly increase BOD discharged to the sewers. Although procedures designed to optimize production, such as blowing out the lines and metering the syrup down to the last drop, there is still significant amount of BOD in the sanitation water due to the concentrated nature of the syrup. With limited warehouse space and as they say, if the plant is producing “Dog & Cats” specialty items, it is difficult to control this source of BOD.

When the 5-Gal Cans come back from the trade and are 1⁄2 full of post-mix syrup, this small operation can be the major source of BOD in a beverage plant. The only solution is to segregate and collect the excess product. Many plants will drain the cans prior to cleaning into a sump and pump the liquid into a storage tank outside the plant. This concentrated BOD stream is then hauled away and disposed of separately. Disposal of high strength BOD streams will be discussed in a later section.

4.3.4 Bag-In-Box (BIB)

Post Mix BIBs that break, leak or come back from the trade are the same problem as the 5-Bal Cans. They represent a major source of BOD. Some plants also collect the BIB waste streams and pump to the same storage tank.

Can/Bottle Crushing can also represent a major source of BOD in the plant. Leaking cans, high/low-fills, out-of-spec product and returned product from the trade are normally disposed of by crushing the container and discharging the residue down the sewer. Some plants collect the waste stream by pumping to the same storage tank.

4.3.6 Sanitation

A 5-step Sanitation is not a large source of BOD since most of the sanitizing chemicals (sanitizers, surfactants, etc.) are used in low concentrations.

4.3.7 Hi-Fills/Lo-Fills, 

Off-Spec Beverages (QC Issues) Off-Spec Beverages, whether caused by Hi/Low-Fills, brixo, CO2, or other reasons, can be generally related to a QC issue which can have many causes. It is beyond the scope of this paper to discuss QC issues in a beverage plant but it suffice to say that poor QC generates more wastewater.

Developing a Water Conservation program is relatively easy – Find out where the water goes and see if the flow or quantity can be reduced.

The obvious steps are:

• Install pressure operated nozzles on all water hoses – Prevent water hoses from running without operator involvement;

• Tighten up leaks and drips;

• Minimize backwash (time and flow) of mixed-media and carbon filters to that absolutely required to maintain sanitation and process efficiency;

• Reclaim backwash waters, if possible;

Optimize membrane efficiency to minimize reject water – have to work with water suppliers for this option;

• Recycle cooling water – eliminate single-pass systems; and

• Eliminate on-site truck washing, if cost justified;

The next step is to wire up the water system with flow meters and a data acquisition system to monitor water flow through the system. The whole issue of automation and controls will be discussed in depth in a later chapter.

6.0 WASTE MINIMIZATION

As mentioned at the front of this paper, “Waste Not – Want Not”. A Waste Minimization program is designed to identify and reduce the amount of waste product and syrup going to the sewer, which is indicated by the BOD in the wastewater.

The primary sources of BOD are listed in Section 3.3. Now that the sources are identified, what do we do about it?

For the 5-Gal, BIB and can crushing processes and for disposal of off-spec products, collection is straightforward; install a sump or tank where the liquid is poured or collected and pumped to an outside storage tank.

For the filling and syrup rooms, the process is a little more complicated. For the syrup rooms, the tank discharge line normally discharges the first rinse to the floor and the liquid runs into the sewer. To collect the first rinse, a process Brixo Meter (http://www.refractometer.com/) and a three-way automatic valve should be installed on the line leading from the tank. When the measured brixo is above a given number, say 5o, the waste is diverted to the storage tank outside. When measured brixo is less than this value, the waste is directed to the sewer. 

To collect high BOD streams from the filling rooms, a sump with a float-actuated pump must be installed. On the discharge side of the pump is a Brixo Meter and three-way automatic valve. During normal filling operation, when the leaks and drips consist of high brixo liquids, the flow is discharged to the storage tank. When low brixo liquids are indicated, the flow goes to the sewer.

6.2 Disposal of High Brixo Streams

6.2.1 “Hazardous Waste” 

Considerations “Hazardous Waste” is a legal term used to designate a regulated, waste material that is deemed to be hazardous by the U.S. Environmental Protection Agency. There are listed “Hazardous Wastes”, which means the name of the wastewater material is actually listed in the regulation (40 CFR 261.33). An example is F001 – Spent halogenated solvents used in degreasing. There are over 500 listed “Hazardous Wastes”. A material may be designated as “Hazardous Waste” by characteristic. Examples are ignitable (will burn), corrosive (acid/caustic), reactive (explode) and toxic (toxic chemicals) wastes.

High Brixo Streams present a potential “Hazardous Waste” problem due to corrosivity, which is defined by materials with a pH =< 2.0 and =>12.5.

Since “Hazardous Wastes” are regulated by the U.S. EPA, there are severe monetary and criminal penalties associated with the improper disposal. To transport “Hazardous Wastes” from the property requires a licensed transporter, which must take the waste to a licensed treatment, storage and destruction (TSD) facility.

The pH of any waste stream that is discharged from a beverage plant should be measured to determine whether the waste is a characteristic “Hazardous Waste”. If the pH of the waste stream is less than 2.0, the waste should be blended in with the balance of the wastewater and neutralized prior to discharge to a municipal sewer.

7.2 Aerobic Wastewater Treatment Options

There are two basic aerobic treatment processes – attached growth and suspended growth, i.e. bacteria growth. Attached growth means that liquid is circulated over a bacterial slime layer, attached to a surface. The BOD diffuses into the slime layer and is metabolized to CO2 and H20, which is washed out of this layer. The slime layer is maintained in an aerobic condition by air or oxygen dissolved in the water circulating over the layer. An example of such an attached growth process is a Biofilter.

Suspended growth means that bacteria are suspended in the liquid and oxygen is supplied by bubbling air into the liquid. The bacteria growth, normally called biosludge, is separated from the clarified liquid. Aerobic processes require nutrients, nitrogen and phosphorus, to be in the proper concentration to support the growth of bacteria and that pH is in the neutral range (6.5-9.0).

A Biofilter, or more commonly known as a “Tickling Filter,” is similar to a cooling tower where water is circulated over plastic media with a high surface area (100m2/m3). For a BioFilter, a bacterial or slime growth attaches to the plastic media surface.

As wastewater is circulated over the media, BOD diffuses into the slime layer where the attached bacteria metabolizes the soluble organics or BOD and the waste products washed out of the layer. The process is maintained in an aerobic condition from vents in the bottom of the tower that allows a draft of air through the tower due to temperature differential from the air and liquid. The BioFilter is an excellent, cost effective process for removing 60-80 percent of the BOD and is space efficient in that towers of up to 30 feet can be constructed. However, removals above 80 percent required larger and larger processes with diminishing incremental BOD removals.

• Quick start-up;

• Dampens out fluctuating flows and BOD loadings;

• Responds quickly to toxic shocks; and

•Generates less biological sludge, as compared to other aerobic processes. 

A Submerged BioFilter is another attached growth process that is very effective. Plastic media is installed in a tank that will be submerged in the wastewater. Air is supplied from air diffusers in the bottom of the tank. An advantage of this process is that the tank can be used for treatment and equalization. With 15-18 hours retention, BOD removals of 50 percent can be obtained in an open tank. With the installation of plastic media with high surface area, oxygen transfer efficiencies are increased and BOD removals are significantly increased.

Activated Sludge and Extended Aeration are suspended growth processes that utilize open aeration tanks to contain the biosludge and the wastewater. The differences between these two processes are the organic loadings and hydraulic retention time. Oxygen is supplied from dispersed air from diffusers located in the bottom of the tank.

A clarifier or sedimentation tank follows both processes to separate the suspended bacterial growth or biosludge, with the clarified liquid discharged to the sewer or river. The sludge is concentrated at the bottom of the clarifier and recycled back to the aeration tank. A typical arrangement is shown in Figure 6.0.

Activated Sludge/Extended Aeration treatment processes are extremely efficient at producing high quality effluents, with BOD5 and TSS concentrations less than 10 mg/L. However these processes are more sensitive than BioFilters to toxic shocks and high loads.

The key difference between these two processes is the organic loading, which is kg (or lbs) of BOD5/kg of MLVSS-day. MLVSS is Mixed Liquor Volatile Suspended Solids and indicates the concentration of bacteria in the biosludge. This loading factor is often referred to as the F/M (food to microorganism) ratio. Activated Sludge processes have F/M ratios greater than 0.1, whereas Extended Aeration is less than -.1. To treat similar waste loads, and Extended Aeration plant would be considerable larger in size.

Anerobic treatment processes are used widely in beverage and fruit processing plants, especially breweries, because of the efficiency and simplicity of the process. Anaerobic processes work very well with simple carbohydrates such as alcohol and sugar. Anearobic processes are carried out in closed tanks where the wastewater passes upward through an anaerobic sludge blanket. The BOD is converted to a gas, consisting of 70 percent methane and 30 percent dioxide. A typical process is UASB (upflow anaerobic sludge blanket).

Anaerobic processes generate methane gas that, if in sufficient quantities, can be used in boilers or electric generating engines. However, most beverage plants do not generate a sufficient volume of gas to be economically viable, the off-gas is normally flared.

7.4 Aerobic vs Anaerobic Wastewater Treatment

It will always come up – What are the advantages and disadvantages of the two basic processes? The advantages of aerobic treatment processes are:

a. Quickstart-up;

b. Simpletooperate;

c. Respond quickly to toxic shocks (e.g. dumps of chlorine);

Disadvantages as compared to anaerobic process are:

a. Generates more sludge;

b. Requires more chemicals for nutrients and to adjust pH;

c. More electrical power;

d. Higher operating costs;and

e. May not be suitable for especially cold climates.

The advantages of anaerobic processes are:

a. More compact footprint due to high loading–6KgBOD/m3-day;

b. Requires the addition of less chemicals;

c. Generates much less sludge;

d. Lower operating cost;

Disadvantages are:

a. Must be operated at temperatures >25o C,optimum is 35oC. Additional heat and insulation is required in a cold climate;

b. Start-up is slow,sometimes requiring up to 6 months;

c. Response to toxic shock is slow;

d. Generates a flammable gas that must be flared.

Beverage Plant A expanded bottled water production, which necessitated expansion of the water treatment plant and installation of a new reverse osmosis membrane. Because of increased production during the summer plus the reject water from the membrane, the wastewater flow almost doubled. To handle the increased sewer flow, part of the wastewater was pumped around the treatment system that included a mass flowmeter. The flows recorded by this flowmeter were reported to the local municipality, which used the data to calculate sewer charges for the flow and BOD. This bypass had been in operation for three years. Because of the under reporting of the flow and BOD, a potential liability of almost $1,000,000 was incurred in addition to potential fines and penalties.

These potential liabilities were caused by a lack of planning during the expansion and an unawareness of the potential liabilities involved in reported false data to a regulatory agency.

Beverage Plant B discharged wastewater to a municipal sewer with the sewer flow determined by deducting metered water flow to the bottling lines from the main water meter. The wastewater was sampled on a time basis by a local laboratory for regulatory purposes and to establish monthly sewer bills. A new municipal sewer district was formed and the sewer flow from Plant B was diverted to a new wastewater treatment plant (WWTP). During the planning for the new WWTP, neither the design engineers nor a representative from the sewer district approached Plant B to verify the sewer flows and BOD concentrations. A problem developed after the new WWTP came on line because of high BOD concentrations, which the sewer district traced back to Plant B. The problem was that the new WWTP was at design capacity and the State EPA would not allow any new sewer connections. No new sewer connections meant no economic expansion for this area, which disturbed the local politicians. Plant B was under pressure to reduce flow and BOD. These problems developed because of two problems. The plant did not know the actual sewer flow and BOD, and did not follow the development of this new WWTP. As a result, the WWTP was constructed without input from the plant. The plant is planning to wire up the water system to identify potential savings and is installing a collection system for BIB and 5-gal lines. They are investigating potential waste haulers.

Beverage Plant C discharges to a municipal WWTP with BOD5 concentrations in the range of 3,000 mg/L. Although the city is in compliance with their NPDES permit and loadings are less than the design capacity, the State EPA is forcing the City to reduce all industrial contributions to the sewer system. As a result, the plant is evaluating options for reducing BOD5 concentrations to less than 1,500 mg/L, which is the value that the City is requesting. However the first priority is to accurately measure the sewer flow and BOD. The existing sampling and monitoring manhole is too small and when the filters are backwashed, the manhole is flooded thereby producing inaccurate data. The sampler is programmed on a time basis and thus collects inaccurate samples, as evidenced by the fact that the same number of samples are collected at low flow when pure syrup is flowing down the sewer as when the filters are backwashed and clean water is flowing down the sewer.

Beverage Plant D discharges to a municipal WWTP, which discharges to the ocean. The plant discharges approximately 150,000 gpd, 2,000 mg/L BOD5 and 2,000 mg/L TSS. The plant is currently paying almost $225,000 per year in sewer charges. The IWD was contacted and it was determined that the sewer charges were dependent only on flow and TSS. There were no charges for BOD. As a result, the installation of a lime softening sludge filter would have a payback of less than 12 months and would save the plant almost $100,000 per year. The problem was that the plant was not aware of the details of their permit.

Phillip L. Hayden, Ph.D., P.E., Htec Systems, Inc., is the author of this white paper on wastewater treatment. He is an environmental process engineer who has a M.S. degree from the University of Cincinnati (1967) and a Ph.D. degree from The Ohio State University (1971). He is a registered professional engineer in the States of Ohio, New York and Florida. He is certified by the American Board of Industrial Hygiene as a Certified Industrial Hygienist and a Diplomat of the American Academy of Environmental Engineers. He served on the FAA Regulatory Advisory Committee, the State of Ohio Emergency Response Commission and served on Dayton, Ohio Regional HAZMAT Board.

Dr. Hayden has been a wastewater consultant to the beverage industry 30 years, having prepared engineering designs of wastewater treatment plants, shipped equipment, served as construction manager, commissioned start-ups and trained operators of over 30 projects all over the world.

He has conducted numerous plant water system audits to evaluate regulato ry compliance, water treatment systems, water conservation and waste minimization programs and wastewater treatment plants.

He has a broad background in environmental, health & safety including water and wastewater issues, hazardous materials, air pollution control and environmental auditing. He has considerable experience in indoor air quality issues, noise, occupational exposure to chemicals, heat stress, OSHA compliance and HS audits.

Htec Systems, Inc.

561 Congress Park Drive

Dayton, OH 45459

937 438-3010 tel 

phayden@htecsystems.com 

www.htecsystems.com