Wastewater and water quality management involve decisions such as capital budgeting, plant expansion, master planning, rate design, and stakeholder involvement. These different decisions require systematic approaches to ensure they are sound, transparent, and defensible. Capital budgeting often requires comparisons across many possible projects, ranging from maintenance priorities to staff training to improving effluent quality. Plant upgrades usually involve only a few options but requiring more careful scrutiny. Challenges posed by environmental issues and shrinking budgets make risks and uncertain ties important considerations.

Decision-making has to be an effective part of project management. Decision quality must be kept high while al locating limited project resources among more tangible tasks. To help our clients make better and more efficient decisions, Carollo has incorporated decision analysis tools into our project approach.

Decision analysis includes ideas and methods recommended by scientific organizations and academic researchers for dealing with risk and competing environmental trade-offs. Rather than “one-size fits all,” decision analysis is an approach that combines technology choices, applied scientific knowledge, and public policy. Today, software for building decision trees, running probabilistic scenarios, or conducting sensitivity analysis makes decision analyses methods practical and cost-effective.

Carollo combines the decision analysis paradigm with our engineering expertise to create the right decision-making approach for each project. This might include working out an appropriate local strategy for a simple outfall re placement or working with stakeholders on a twenty-year master plan. Running Monte Carlo simulatons of project ed effluent loadings or searching a large decision tree to optimize collection system design is another way Carollo integrates decision analysis with engineering.

Whatever the choices, Carollo ensures decision quality by matching project resources to project needs. Carollo creates project approaches that address all relevant benefits and costs. We use a range of decision aids and software tools to interact creatively and productively with different stakeholder groups.
A key to good decision-making is identifying how choices create value. Value can be improved water or effluent quality to consumers, regulators or the environment; efficiency improvements and cost savings; or more predictable and less risky operations through a better-trained work force. Carollo’s “values-focused” approach means that no technology or design is automatically “best,” but is chosen because it will realize the greatest value across competing goals and objectives. The values-focused approach is also a leading concept in decision analysis.

The first step is to organize or “frame” the decision through what the project should achieve. What are the benefits of improved knowledge of effluent flows and loads? What risks can be avoided by prioritizing maintenance tasks? What improvements to water quality are possible through watershed management? What health or ecological outcomes are improved through increased chemical treatment? Technology options, risks, and uncertainties are then analyzed for how they influence such values. A value-focused approach leads directly to more efficient and strategic project management. Assumptions and constraints, from future regulatory requirements to customer satisfaction, can be identified early on to anticipate tough trade-offs and set expectations for project success. Decision quality is assured by assigning resources to the modeling and data collection tasks which provide the most valuable information.

Carollo uses many decision analysis tools to help clients understand difficult choices and tradeoffs. Decision trees are used to incorporate risk and uncertainty. Through decision strategy tables, novel treatment and control options are combined to quickly screen solutions or to define mixtures of simpler options. To help think through new modeling approaches, influencediagrams are used to identify important cause and effect relations, and to put them in easily understood graphical formats.

Carollo uses these techniques at the level that is appropriate for plant managers, district staff, technical experts, or decision-makers. We choose media ranging from flip charts or a white board to interactive software displays. By using simple formats for these decision aids, they become excellent communication tools. Carollo helps clients build bridges between the technical perspectives of engineers and the policy perspectives of regulators and elected or appointed officials.

Decision analysis is a powerful aid to project design and execution, helping wastewater and water quality decisions become both more efficient and less controversial.
The key to working with stakeholders is organizing their multiple views of an environmental decision. In decision analysis, these multiple views are captured as competing stakeholder values. These include many benefits or costs such as ecological quality, land use, drinking water quality, human health outcomes, wastewater service, consumer or other financial costs, water recycling benefits, or neighborhood impacts such as odors, noise, or traffic congestion.

Decision analysis requires the separation of issues. Distinct values, like financial costs, health, or ecological outcomes, are carefully defined and quantified on their own terms. Often, stakeholders all agree that higher quality drinking water, improved fish habitat, or lower costs are all desirable; the question is how much, at what cost, and to the exclusion of what else? Promoting a values-focused approach among stakeholders creates a shared perspective on overlapping goals and issues. It also supports innovative approaches to tough environmental tradeoffs.

Carollo promotes stakeholder dialogue by integrating engineering science, stakeholder concerns, and environmental policy. As engineers, we ensure that the dialogue is both efficient and fact-based through the metrics or measurement criteria used to best compare options: what is achieved by enhanced chemical treatment, source control, conservation, or other choices, and how do we quantify those outcomes?

Carollo aims to facilitate and improve difficult public works decisions for all participants. Among Carollo’s innovations is a unique stakeholder “opinion summary.” The opinion summary allows for “majority” or “minority” opinions, and various rankings and recommendations. Even when stakeholder consensus is not perfect, an informative range of inputs is delivered to district boards, city councils, or regulators as final decision-makers.