Treatment at the end of pipe is not cost-effective
By Alex Keen, President and CEO, ALTECH Group
Wastewater treatment is a concern in most industrial sectors, however, the food and beverage industry is potentially more concerned than most. With the pressure from municipalities of rising water charges and the application of sewer bylaw standards, the cost of water and wastewater measurably impacts the overall cost of production. At the same time, it is a fact that many countries in the world have adapted to water costs that are two and three times the costs in Canada. As water costs rise to reflect the requirements for infrastructure renewal, the food and beverage industry in Canada must respond with new technology applications to reduce and/or recycle water and treat wastewater streams.
Pressure on the Food and Beverage Industry
The food and beverage industry is traditionally a user of large volumes of water. In addition to water as a component of many products, it is a convenient, clean, and a relatively inexpensive resource. Because food materials are easily moved or quickly dissolved in water, it becomes an easily available solvent and method for conducting cleanups and other production needs. Since the company is only cleaning food debris, it is not generally considered hazardous by the generator. It is sometimes difficult for company staff to fully understand the impact of putting the water into the sewer.
With the rising costs of municipal infrastructure support, both for water and wastewater service delivery, and the provincial down loading of funding for some of these services, there is much more pressure on the municipality to cover its real costs of operation. With the involvement of private/public partnerships encouraged, there will be a further move to rising costs for these services.
It is not surprising, then, that municipalities are entering into structured programs of raising water rates. As well, municipalities are, perhaps, more aggressive at establishing surcharges for over-strength discharges.
Obviously, the cost to food companies, then, is twofold, namely, rising water charges and increases in wastewater surcharges. Finally, in some cases where residential and commercial development is restricted by the capacity of municipal wastewater treatment, the municipality may not allow over-strength agreements because it unfairly restricts the ability to approve new residential or commercial development which results in more tax revenue.
Pollution Prevention is the Key
Particularly in the food industry, treatment at the end of pipe is not cost-effective. The company must review practices upstream and practise pollution prevention or control at the source if it is going to find a cost-effective way to use water. Because water use is such a major component of production costs, ranging from 2%-14%, this will be the secret to being more competitive in the future.
Implementing water recycling and reduction strategies has a two-pronged effect. Not only does it reduce municipal water charges, but it also reduces the cost of treatment and/or recycling equipment since hydraulic flow is the most influential factor in the cost.
There are a number of features of the food and beverage industry that make it practical to investigate smaller, treatment-at-source solutions. Production is usually a combination of high strength washouts and cleanups, combined with high-volume uses of water with low levels of contamination. To combine these streams is to increase the cost of treatment by diluting the high-strength contaminants in the larger volume of water.
Payback Options
There are a number of factors that can have an impact on technology payback calculations, including:
Elimination of Bylaw Surcharge.
Bylaw surcharges are often between $50,000 to $200,000. As these are direct costs to food companies and are likely to increase rather than decrease, they become an important part of the payback calculation for new equipment. As an added incentive, several municipalities offer a program that repays a portion of the capital back, based on past surcharges paid.
Reduction of Water Charges.
Reduction in water usage through projects such as better collection of rinse waters, separating clean water streams from dirty ones, and the potential use of membranes all can easily reduce water consumption by 30%-50%. At approximately $0.95 per cubic metre (including water and sewer charge), this could amount to significant savings at low capital cost and have the added benefit of reducing the hydraulic flow and cost of final treatment.
Reduced Waste Transport Costs.
The food industry generally has lower cost waste disposal options because the waste streams are generally considered to have some nutrient value where disposal options can include land application, livestock feed, composting, etc. However, many water streams are very dilute with BOD contaminants and the cost of haulage becomes expensive. Membrane applications have provided attractive pay backs by simply concentrating the waste and reducing haulage by as much as 80%.
There are substantial opportunities in the food industry to manage water and wastewater to reduce costs. It is a matter of carefully evaluating treatment at the source in combination with newer, lower cost technology applications.
This article has been abridged.