Step 1 - Baseline Water Footprint

This first step will help you capture a baseline of your current water usage and identify sources of risk like leakage, inability to expand production, and compliance concerns. Innovative companies perform water assessments on a regular basis to prepare for more stringent regulatory pressure in the future. In some cases customers are demanding suppliers become more environmentally progressive in an effort to reduce their own legal risk or simply to improve brand image. Wal-Mart is a good example of that. Performing water assessments is, in essence, a search of hidden dividends, leading to improvements that include water savings and improved wastewater quality standards.

Water Balance

Numerous levels of data can be collected. It is important that you first focus only on the attributes that are necessary to calculate an efficiency goal relevant to you. A water balance provides a full picture of every water-consuming component on site, and serves as the first step in uncovering hidden opportunities for savings. We propose the water balance format provided below.

The water balance template includes six basic categories under which any water consuming entity on-site should be included.

  • Inlet water pretreatment
  • Cooling towers
  • Boilers
  • Processing (any water consuming facility which is a part of the production process)
  • Wastewater plant (if it exists), or water effluent
  • Other (ash ponds in a power plant)

For each unit operation, capture and diagram the water balance: that is, write down all flows of water into and out of the operation, and verify a mass balance of both the water flow and the key chemical constituents within or added to the water.

This "mass balance" ensures an accurate understanding of the operation, and that no significant flows are forgotten (see Figures 2 and 3). In many cases, a particular component can be fed from an on-site source as a way to recycle water.

Measured data can be retrieved from the following sources:

  1. Flow meters
  2. Utility bills
  3. An engineering estimate based on previous measurements
  4. System specs
  5. Assistance from a water expert

 

 

Capturing Water Related Costs

In addition to capturing related flow capacities, collecting all related costs will provide an economic base to the opportunities identified in Step 2.

Direct Costs

  • Water use – $/volume x volume per period (minute/day/year). Volume units are typically gallons or m3
  • Wastewater discharge fees
  • Pretreatment technology
  • Energy costs associated with water use, If possible (heating, pumping, water treatment etc.)
  • Regulatory costs (permits, compliance assessment, etc.)
  • Costs for water management measures (staff time and resources, technology, equipment and materials)

Indirect Costs

  • Site location limitations
  • License to operate or grow (marginal cost for capacity expansion)
  • Relationships with stakeholders (suppliers, financial institutions, employees, regulators, customers, shareholders, neighbors and local communities)
  • Loss or damage of ecosystem/species

 

Source: Water Efficiency Manual, North Carolina Department of Environmental and Natural Resources, edited.

The deliverable completed in this step is a detailed water balance including flow capacities and related costs.

 

Continue to Step 2 - Identify Efficiency Opportunities