Internship Developer Jobs in Sioux Falls, SD (NOW HIRING)

Department: Water/Wastewater

Employment Type: Full Time

Location: Sioux Falls, SD

Compensation: $70,000 - $125,000 / year

Founded in 1973, ISG is a nationally recognized, multi-disciplinary firm delivering full-service architecture, engineering, environmental, and planning solutions. We are looking to add to our Water/Wastewater team with an Industrial Water/Wastewater Engineer. We are building a reputation for consistency, excellence, and thought leadership—and we want to be the best in the country. In our industrial water/wastewater practice, that means solving complex problems quickly, tailoring solutions to unique process conditions, and continuously learning and sharing knowledge through projects, publications, and conferences.

We are seeking an Industrial Water/Wastewater Process Engineer who thrives in fast-paced environments and is energized by variety—variety in technology, client operations, and project challenges. Unlike municipal work where loads and solutions are often consistent, our industrial projects can vary widely and move quickly. The right person will be inquisitive, data-driven, and confident in doing sound process design—not copy/paste—while applying common-sense engineering to validate that calculations and outcomes make sense.

This role will contribute to industrial client projects (e.g., food & beverage, dairy, agriprocessing, manufacturing) by developing process designs for water and wastewater treatment, reuse, and related systems. You’ll collaborate with senior engineers, mentor interns/early-career team members, and actively engage in technical learning and industry presence.

• Process Design & Calculations: Develop process designs and perform detailed calculations (mass balances, hydraulic profiles, equipment sizing, process modeling) for industrial water/wastewater systems (physical/chemical, biological, pretreatment, reuse)
• Tailored Solutions: Analyze influent/effluent variability and site‑specific conditions to create solutions that fit each client’s process—no “one‑size‑fits‑all”
• Fast‑Paced Project Delivery: Manage multiple, fast‑moving industrial projects with clear priorities, organized workflows, and proactive communication
• Technical Documentation: Produce PFDs/P&IDs, specifications, reports, and QA/QC checklists; coordinate with multi‑disciplinary teams and vendors
• Field & Implementation Support: Support site visits, pilot testing, startups/commissioning, and operator training as needed
• Data‑Driven Decisions: Structure and interpret data to inform design decisions; validate results with practical judgment (e.g., sanity‑check mass and flow balances)
• Continuous Learning & Thought Leadership: Contribute to internal knowledge‑sharing, present or co‑author technical papers, and represent ISG at industry and technical conferences
• Collaboration & Mentorship: Work independently when appropriate while knowing when to ask questions, reference resources, and engage teammates; help grow our intern program and early‑career staff

• Education: B.S. in Chemical Engineering or Environmental Engineering (preferred). Strong process‑focused candidates from related disciplines may be considered
• Experience: 2‑4 years of relevant experience in industrial or water/wastewater process design. (We welcome more experienced applicants, understanding availability may be limited.)
• Process Mindset: Demonstrated ability to think critically, ask the right questions, and tailor designs based on unique process conditions
• Common‑Sense Engineering: Habit of validating whether results are physically/logically reasonable (e.g., ensuring mass/flow balances make sense)
• Data Orientation: Strong organization and comfort relying on data to drive decisions; proficiency with Excel and engineering calculation tools
• Communication: Clear, concise verbal and written communication with clients and internal teams; ability to work independently and proactively seek guidance when needed.
• PE or EIT certification or progress toward PE licensure
• Experience with industrial sectors (food & beverage/dairy, agriprocessing, manufacturing)
• Familiarity with process modeling tools and developing PFDs/P&IDs
• Experience presenting at or attending industry and technical conferences (e.g., WEFTEC, Water Reuse) and interest in publishing/presenting technical content
• Membership or engagement with professional organizations (WEF, AWWA, Water Environment Federation chapters, etc.)

• Medical, dental, and vision
• Paid time off, pro-rated amount available on your start date
• Paid holidays and paid volunteer time
• Paid parental leave
• Bi‑annual profit sharing
• Employee Ownership Stock Plan (ESOP)
• 401K retirement plan
• Life insurance
• HSA and FSA options
• Bereavement leave
• Supplemental voluntary benefits
• Short term and long‑term disability
• Parking reimbursement, varies on office location
• Cell phone plan reimbursement
• Mileage reimbursement for ISG-approved travel