Wastewater Process Engineer and Modeler

Carollo Engineers

📍Phoenix, AZ
Posted May 26, 2026

Job Overview

Position

Wastewater Process Engineer and Modeler

Company

Carollo Engineers

Location

Phoenix, AZ

Work Type

On-site

Job ID

li-4260769703

Job Description

Overview
Carollo Engineers is a leading engineering firm dedicated exclusively to water. For over 90 years, we've specialized in the planning, design, and construction of water, wastewater, stormwater, and reuse facilities, bringing innovative and sustainable solutions to the water sector's most complex challenges.

We work with water agencies, municipalities, utilities, research organizations, and private companies across various industries, including technology, manufacturing, and beyond. These clients choose Carollo because we employ some of the most knowledgeable and experienced professionals in the world. When you join our team, you'll work alongside industry leaders who are advancing the science of water, protecting public health, and building resilient communities.

Carollo's vision is to be the best water consulting firm and the best place for you to build your career. If you're passionate about making a difference in this critical field, we invite you to explore a career with Carollo.

Responsibilities

  • Perform wastewater process modeling, designs, conceptual designs, facility layouts and prepare reports, plans, and specifications under direction of principle engineers and technologists

  • Independently evaluate and apply engineering techniques, procedures, and criteria using judgment in making adaptations and modifications

  • Evaluate and analyze numerous treatment technologies, investigations, surveys, structures, or equipment with basic and complex features

  • Project engineering for wastewater treatment and collection systems

  • Testing materials and processes

  • Report and technical memoranda writing

  • Wastewater process modeling and studies

  • Research investigations and piloting

  • Present work products to clients and at local and national conferences where appropriate

  • May supervise or coordinate the work of technicians, drafters, and others who assist in specific assignments

Qualifications

  • Demonstrated ability in biological, physical, chemical process modeling, hydraulics, and principals of wastewater treatment plant design

  • Ability to communicate effectively with clients and project team and deliver high quality services within budget and schedule constraints.

  • Familiar with codes and regulations related to water pollution control

  • Knowledge of structural and geotechnical design concepts, analytical laboratory techniques, and engineering methodology

  • Master’s degree in civil, environmental, or chemical engineering

  • 5-10 years of wastewater process and design experience in the field of environmental engineering with an emphasis in hydraulics, physical, chemical, and biological treatment processes, and treatment plant design.

Preferred Qualifications

  • Doctorate degree in civil or environmental engineering

  • Wastewater process modeling software including BioWin

  • Publication of peer-reviewed papers

  • Engineer in Training Certification or Passed FE exam

Compensation Range
An employee’s pay within the salary range will be based on several factors including, but limited to, relevant education, qualifications, certifications, experience, skills, seniority, geographic location, performance, and business or organizational needs.

Other Compensation And Benefits
Carollo is committed to providing employees with a competitive, comprehensive benefits program that provides the support employees and their families need to lead healthy, productive lives. Carollo’s benefits package includes paid time off and holidays, comprehensive health insurance coverage, pre-tax savings account options for healthcare, dependent care and commuter expenses, disability insurance and life insurance options for you and your dependents. We also offer free Caregiver Support, Travel Assistance, counseling services, discount programs, and a Lifestyle Reimbursement Account. Other compensation that may be available includes: 401(k) company contribution matching, tuition reimbursement, discretionary bonuses, career advancement bonuses, professional registration bonuses, employee referral bonuses, and compensatory time for exempt employees. Flexible work arrangements may also be available. Eligibility for benefits varies based on employment status.

Interview Prep

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Key Skills

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Practice Questions

💡Technical Questions (3)
  • 1.Can you walk me through your experience using BioWin or similar software for wastewater process modeling, and how you ensure your models accurately reflect real-world plant performance?
  • 2.When evaluating and selecting treatment technologies for a facility layout, how do you balance innovative, sustainable solutions with strict water pollution control codes and regulations?
  • 3.Describe your approach to designing hydraulics and process layouts for a wastewater treatment plant upgrade. How do you handle complex features within existing infrastructure constraints?
🎯Behavioral Questions (3)
  • 1.Tell me about a time you had to deliver a high-quality wastewater process design or report under a tight schedule and budget constraint.
  • 2.Describe a situation where you had to present complex engineering or modeling results to a non-technical client or stakeholder group.
  • 3.Give an example of a time you supervised or coordinated the work of technicians and drafters on a specific wastewater engineering assignment.
🧩Situational Questions (2)
  • 1.You are leading a wastewater process study and your pilot testing results contradict your initial BioWin modeling predictions. How would you handle this discrepancy?
  • 2.A client asks you to value-engineer a wastewater treatment facility layout by removing a redundant process unit to save capital costs, but you know it compromises regulatory compliance during peak flows. How do you respond?

Resume Keywords

Make sure these keywords appear on your resume

BioWinWastewater Process ModelingHydraulicsTreatment Plant DesignPilotingTechnical MemorandaWater Pollution ControlBiological TreatmentCarollo EngineersProcess Design

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