Choosing an Engineer For Your Water or Wastewater System Project

When you decide where to buy a home and to live, what do you consider? Most likely you looked for a community where the citizens are happy, healthy, and comfortable. Part of being all three is having a clean, safe, and constant water supply and clean environment. Many of us take for granted that when we turn the faucet on we will be able to get a glass of water or that when we flush the toilet our waste will be carried away and treated somewhere without polluting the environment. The design of the infrastructure is the water or wastewater engineer’s specialty.  Other titles are environmental engineer, sanitary engineer, or civil engineer.  Their job is to design and build the tools, equipment, and infrastructure that provide us with clean water as well as to monitor the safety of our water and protect our environment.

Good engineers have experience and skills to complete your project efficiently and accurately.  They know how and when to multitask; they can focus on details as well as the big picture; they interpret requirements and make good judgments; they make educated decisions about risk; they are team players and listen to your opinions, needs, and goals; they brainstorm, whittle down to viable options, and make decisions; they empower, mentor, and teach others; and they take and give constructive criticism.

How do you choose the right engineer for your project?

The work of an engineering consultant is varied. Because engineering is such a wide field, there is almost no limit to the work a consultant can perform. They perform several different types of work, for many different types of businesses. Engineering consultants find solutions that meet or exceed the needs of their clients.

Choosing a consultant to help plan, design, and oversee a wastewater project is an important decision for any community or owner. The success of the project will depend, in large part, on the knowledge, experience, and ability of the person or firm the community hires.

Finding the right people with the appropriate qualifications and experience, therefore, is an extremely important task. But for many small communities and owners, the selection process can be difficult.

Communities should hire consultants based on a variety of factors, including their experience and success in working with other small communities or owners on similar projects.

Unfortunately, it is not uncommon for a small community to have had a less than ideal working relationship with an engineering consultant. While most consultants do good work and are very well qualified, it is extremely important that they have experience with the specific type of small project that you have and set client relationships as a high priority.

Kathryn Mills of Mills Engineering has 20 years of experience designing water and wastewater projects in Arizona.  Mills Engineering can help with your water or wastewater design project in Arizona. We can help you supply safe water to your project and safely dispose of the wastewater to preserve the quality of life in our communities.

Different flavors of Consultants

How to hire an engineering consultant?  It can be for one project with a contract or on a longer term basis as a consultant, depending on what you need.


A “contractor” is typically hired for one project (via a “contract”), and the relationship is often more technical than personal.  Once the project is complete, the contract ends.  The engineer has completed the work and the focus on the project ends.

They may be back for a future project.  Doing a good job on the first project certainly means future consideration for a subsequent project.  And the future work is just as often a new project as opposed to working on the old one.


A “consultant” constract is more about a long-term relationship than it is about a specific project.  Examples would be consulting to provide engineering design and permitting for a variety of small improvements and to assist with ongoing compliance and operational challenges.

What to Look for in an Engineer

The primary considerations in selecting an engineer are relevant experience in the types of services you need and demonstrated ability to serve clients in a timely and effective manner. This article will help you to decide what questions to ask and what criteria to use for your project.

Whether it is a 20-foot water line or a simple septic tank and disposal trench to serve your new house, a state-of-the-art treatment system and irrigation disposal system, an on-site wastewater system, a short sewer pipe connection, a small well treatment system, miles of pipe to serve your subdivision, a sewer lift station and pressure pipe connecting to the local sewer system, a commercial treatment system, or a multiple well water system with tanks and booster pumps, Mills Engineering can help you.  We specialize in the design of water and wastewater projects.

We also help educate or involve the public in the project and the decision-making process; develop an operation and maintenance strategy or program for the system; and/or will be available to the community after the project is completed to work through any design flaws or to assist with other unforeseen difficulties that may arise with the operation of the system.

Consider Cost

Before soliciting proposals, you need to have some idea about what you, your organization, or your client can afford and how to pay for the different costs associated with the design, construction, operation, and eventual replacement. These costs may include permit fees, administrative and accounting costs, routine repairs and maintenance, system operation costs like electricity, and operators’ salaries in addition to the design and construction.

What procedures should you use to select an engineer?

If you are a government entity, or if you are applying for state or federal funding, you may have a prescribed selection process to follow. Ask your attorney or the funding entity before you get started.

Selection Criteria – Questions to ask potential firms or engineers:

  1. Experience.  What type of projects does the engineer specialize in?  How long has the firm or engineer been in business?  How many projects similar to your project has the engineer designed?
  1. Make sure the engineer has a current Professional Engineer’s license (P.E.) by checking with the state board of technical registration.  The firm providing engineering services must also be registered and have a P.E. on staff.
  1. What kind of insurance does the firm or engineer have?  They should have both Professional and General Liability insurance.  If they have employees, they must also have Workmen’s Compensation insurance.
  1. Are they a member of the local Better Business Bureau (BBB)?  What is their rating?
  1. Are they a member of Industry or Trade Organizations to keep current with technology and regulations?
  1. Can they provide references for owners or contractors that they have completed projects for recently?
  1. How do they determine the fees they will charge for the project?  Will it be a lump sum fee based on a scope of work?  Will it be itemized with a fee for each task?  Or will it be an hourly fee with an upper limit?  Will revisions be included if the regulatory agency wants changes made to the plans?  Will construction services like bidding, answering contractor questions, and reviewing installed work be included?

Procedural Steps to Take:

  1. Compile any readily available information about the site and project requirements.  Prepare a brief written description of the work you think needs to be done.
  1. Ask for proposals and interview three or more of the engineers/firms expressing an interest, based on the selection criteria.  Ask them for references from previous projects.
  1. Contact their references and ask how well the engineers performed the assignment. If feasible, visit the references’ completed projects.
  1. Meet with the engineer, if necessary, to discuss any items not fully addressed in the proposal or any modifications.

When to sign the contract?

If the proposal is acceptable, proceed to the contract stage. If you don’t have a standard contract, the engineer may provide one.

If a grant or loan is involved, ask the funding agency to review the contract before you sign it. If you are getting a bank loan, the bank will also want to see the contract.

When the terms and conditions of a contract are mutually acceptable and the contract is signed, let the other engineers you interviewed know of your selection.

If contract terms can’t be mutually agreed on, end negotiations with that engineer and start the process with the second-ranked engineer.

Do you have a specific question about hiring an engineer or Mills Engineering that isn’t answered by this article? Post your question on or contact us directly.  If you are interested in finding out how Mills Engineering can help you with your water / wastewater design project, please contact us. We welcome the opportunity to speak with you! Contact us now to set up a free initial consultation.