Not too long ago, water was inexpensive, high quality, and plentiful for industrial users. Whether water came from municipal supplies or from surface or ground water sources, it reflected a small portion of their operating cost. Industry-specific standards for wastewater discharge regulations emphasized a level playing field regardless of a plant’s location or design. Water and wastewater decisions were primarily technical (i.e., meet the quality requirements) and secondarily financial.
However, during the last ten years drought, competing uses, and environmental limitations have made water less available. Consequently, its cost has increased dramatically. A direct relationship has developed between water quality and water cost. Regulatory limitations on wastewater discharges have become more strict and site/process-specific.
Responding to these factors since 2007, many corporations began adopting a policy of “triple bottom line,” or “profit/people/planet” (3P), in which a nexus of economic, social, and environmental factors constitutes a viable and responsible business strategy, often driven by shareholders. Social and environmental responsibility has been pushed down to the local level; greenhouse gas reduction is practiced by industries worldwide; and decreasing global water, energy, and environmental footprints is now emphasized in the corporate board room.
Linear Approach to Project Work is History
In the past, industrial water management projects were relatively simple and linear: Engineering solutions proceeded forward, step-by-step, to a technically sound and cost-effective result without much deviation from standard practices or a more intensive examination of water use or wastewater generation.
As engineers, we worked with the plant to establish the essential facts: The quantity of water the plant requires and discharges; the quality of the water before its treatment; water quality requirements for use inside the plant; the discharge limits permitted under federal regulation by the National Pollutant Discharge Elimination System (NPDES), which were the same for similar types of plants; the regulatory deadline for implementation; and demonstrated technologies that would do the job, usually including a well-accepted form of biological treatment, sometimes followed by filtration or adsorption. Estimating the upfront capital and on-going operating costs was then relatively straightforward; the least cost solution that met technical requirements was implemented.
Non-Linear Approach to Project Work Today
Today, industrial water management projects are more complex and substantially non-linear; that is, each step frequently reveals complexities that force engineers to revise their assumptions and to come back a step or two and work through the issues, now better understood, and to then proceed accordingly. Such stops, starts, and circles are the new norm.
Industrial water projects typically follow more involved and circuitous steps. We inventory the quantity and quality of water uses and wastewater sources and prepare a water balance of the existing case. We identify and evaluate options for reducing, reusing, and reclaiming water and then prepare a water balance of the “possible” case. This enables us to identify alternative raw water sources, including the quantity and quality available, and to analyze the permutations and combinations of available water sources to meet the client’s needs. We evaluate treatment technologies against the project’s criteria, including minimum water consumption; raw water use of lowest quality possible; the required wastewater discharge quality; minimum discharge volume; minimum residual waste; minimum energy consumption; minimum air emissions; and minimum production of greenhouse gases. We then rank options according to financial, social, and environment impacts to ensure consistency with the company’s water management strategy. Only then do we implement the solution.
To demonstrate this work, consider the following project for a relatively large chemical plant in a coastal industrial development. The assignment was to develop a plan to meet new effluent discharge limitations at minimum cost while complying with 3P (Profit/People/Planet) corporate policy.
We first prepared an inventory of existing conditions, situation, requirements, and data to establish the starting point. The owners were interviewed to understand their plans for the facility and specifics of their 3P policy. The current case water balance was then defined and compared to industry benchmarks. A future case water balance was prepared with improvements ranked according to ease, cost, and impact of implementation. Using an iterative approach, the team circled back to the starting point and the 3P policy criteria, until the best, not actually the least cost, case was identified. The plant was able to achieve water reuse/reduction of 20 percent at minimal cost; but after looking at the options, management elected to invest millions of additional dollars to achieve more than 40 percent reduction. Multiple wastewater treatment options were screened and compared, considering costs; discharge quality; gas emissions; space requirements; simplicity; aesthetics; public perception; and ability to obtain permits. We recommended a treatment wetlands process based upon all criteria, especially its relatively low capital and operating cost (less than 50 percent of the next lowest cost option) and its natural fit with the neighboring mangrove swamp. In the end, the company concluded that the need to acquire land, the local anti-industry activism, and lack of strong political support made this too steep a hill to climb. Once again, the team circled back to the 3P policy criteria and screening of options. The final choice was a compromise solution favoring People over Profit and Planet, at a cost of more than double the original selection.
This demonstrates the non-traditional approach and conclusions, sometimes foreign to engineers; cost is one of several factors in decision making and is increasingly a secondary one.
The steps industrial water management specialists follow today and the project example discussed above reflect how water management projects have become dramatically more complex. Clearly, the project pathways from problems to solutions—due to limited sources of water, known impacts to the environment, stricter regulations, greater stakeholder concerns, and all associated costs—are more non-linear. As project solutions are understood in relation to the 3P “triple bottom line,” the definition of success, which includes the social and environmental components, has become less quantifiable and more intangible. This reveals something just as significant in today’s water management practice: Engineers and scientists are forced to abandon their mind-sets and their traditional, now outdated, simplistic, cost-centric approaches to industrial water management.
Perry Lankford is Vice President, Commercial & Industrial Water & Wastewater for Tetra Tech. He is based in Nashville, TN. Tetra Tech is the nation’s #1 firm in engineering and consulting services for water resources, as ranked by Engineering News Record.
