Carbon and water footprints
June 24, 2014
by Anne Giesecke
Companies are being asked to calculate environmental footprints for carbon emissions and water use. The purpose of measuring these elements is to reduce the numbers. The estimate calculation for carbon emissions is different from the footprint for water. This article will describe the different footprints.
Many states now require the calculation of greenhouse gases as carbon dioxide equivalents for air permit applications. The concern for climate change is forcing reduction goals for the carbon footprint of nations and companies.
The focus of the calculation for most food plants is the carbon dioxide and other products produced from the burning of fossil fuels such as diesel, petroleum and natural gas both on-site and from the purchase of electric power. In addition, refrigerants and wastewater treatment gases, such as methane, may be in the count. Refrigerants and methane are converted to a carbon dioxide equivalent. Carbon emissions are measured in metric tons. For example, the carbon equivalent of 1 metric ton of methane equals 21 metric tons of carbon dioxide.
One program to calculate a carbon footprint is found at Carbon Footprint (www.carbonfootprint.com/businesscalculator.aspx). For a complete article on calculating a carbon foot print see Milling & Baking News of May 9, 2011.
Shrinking the carbon footprint requires using less natural gas (optimize oven burners), less electricity (fix air compressors), less refrigerant (fix leaks), and best use of water to minimize wastewater treatment.
In June, the Environmental Protection Agency proposed a rule to force states to reduce their greenhouse gas emissions (www.epa.gov/cleanpowerplan). Implementation is expected in 2016. States where power plants use coal such as in the Midwest, the Ohio Valley and the Southeast, including Georgia and Florida, have relatively lower electric rates. The lower rates may increase as controls are required on the power plants. The increased use of natural gas may increase cost of that fuel.
Different goals for states
Cap-and-trade, market-based programs exist in 10 states, and more programs will be implemented to address regional goals. Each state has a different carbon reduction goal. For example, West Virginia must cut carbon by 19.7% but Colorado must cut by 35.3%.
On the other hand, states may fund incentives to use alternative energy, such as solar power. One example is the Illinois House Bill 2427. According to Elam and Strong at Barnes & Thornburg, the bill unlocks $30 million of roughly $54 million in existing state funds for investment in new renewable generation such as solar-fueled distributed generation.
Measuring the water footprint
The water footprint is a different kind of estimation. One component is directly measured by the utility bill for the purchase and discharge of water. However, the cost of water has many other components and to define a realistic reduction goal all expenses need to be evaluated.
According to The Alliance for Water Stewardship Tool 1.0, located at aws.chug.gr/assets/documents/AWS_Standard_Full_v1.0_English.pdf, in addition to purchase and discharge, water-related costs may include:
• Total amount spent on energy for the movement of water, and for the heating and cooling of water; and
• Cash payments made outside the organization for water-related materials, product components, facilities and services purchased, such as, payments for contract workers, employee training costs and payroll for water-related staff.
The scope of the water footprint is everything from the source of the water to where it is going, including the risks in a facility’s catchment area. The most obvious facility water streams are process water, sanitation, water for drinking fountains, wash stations, break rooms and rest rooms and waste water treatment.
Reducing water use must be reviewed holistically. For example, using less water for sanitation may result in higher concentrations of regulated pollutants, such as biological oxygen demand (BOD). Water permits limit concentrations. Dry cleanup may increase food waste amounts. Also note that water and energy costs are closely linked. For example, a new pan washer may use less water but more energy.
The water footprint includes outside water management features such as lawn sprinklers, a rain garden, storm sewers, and aeration ponds.
An inventory of the catchment area risks should consider the potential for flooding of the sewer systems, particularly combined sanitary and storm water systems. Flooding of sewer systems can require boil water alerts and possibly the need to have an alternative source of drinking water for operation of the facility. The potential for flooding from storm events may affect delivery routes and flood buildings. Flood scale waterline breaks are increasingly common in areas with aging infrastructure of the water delivery and sewer systems.
The water footprint of an operation is broadly defined and described by how water is used. Reducing the water footprint may be as simple as fixing leaks and changing hose nozzles for sanitation.
A carbon footprint may be calculated on a computer. A water footprint is a list of uses, some uses that may be quantified and many that cannot. Understanding the carbon and water footprints of an operation may lead to a better use of resources and the setting of realistic percentage reduction goals.