Demo

Senior Engineer - Water & Wastewater Conveyance

Interagency Inc.
Washington, DC Full Time
POSTED ON 9/9/2026
AVAILABLE BEFORE 10/8/2026
Senior Engineer – Water & Wastewater Conveyance 
Location: Hybrid – DC-MD-VA region 

About InterAgency Inc:
InterAgency Inc. is a dynamic and fast-growing water resource consultancy specializing in infrastructure planning and environmental compliance across the D.C., Maryland, and Virginia region. Over our 15-year history we have provided facility design, regulatory coordination, NEPA and Clean Water Act permitting, and program management support on multibillion-dollar deep tunnel programs, biosolids facility upgrades, coastal resilience projects, and drinking water access initiatives.  

Position Overview: 
InterAgency Inc. is seeking a Senior Engineer to serve as a senior technical authority on our water and wastewater conveyance work. This is a deeply technical role in a practice we are actively building. We are looking for someone to lead the engineering on active programs, set and enforce technical standards, and mentor the engineers who join the practice. Our current projects center on water and wastewater conveyance in the Mid-Atlantic region, with our current client base including DC Water, WSSC, Fairfax, Loudoun, Arlington and AlexRenew.  

Key Responsibilities: 
  • Serve as the senior technical resource on water and wastewater conveyance assignments, including hydraulic capacity evaluation, alternatives analysis, rehabilitation versus replacement strategy, pipeline and force main design, pump and lift station design, diversion and flow control structures, and trenchless and tunnel engineering support. 
  • Perform and direct hydraulic and hydrologic analysis and modeling, and review models, calculations, and drawings prepared by others. 
  • Prepare, review, and seal engineering deliverables as a licensed Professional Engineer, and provide an independent technical review of work prepared by staff and teaming partners. 
  • Serve as day-to-day technical lead on assigned task orders, coordinating with engineering partners, client staff, and InterAgency colleagues. 
  • Provide construction-phase engineering support, including submittal and RFI review, design clarification, field observation, and commissioning support. 
  • Mentor and review the work of project engineers and EITs, and contribute to the QA/QC standards, design templates, and technical procedures for a startup engineering practice. 
  • Contribute technical content to SOQs, proposals, scopes of work, and fee estimates. 
  • Manage scope, budget, and schedule on assigned task orders and serve as a client-facing point of contact for technical delivery. 

Qualifications: 
Required Qualifications: 
  • Bachelor's degree in Civil Engineering, Environmental Engineering, or a closely related discipline.  
  • 10 years of progressive engineering experience with a primary focus on water and wastewater conveyance (gravity sewers and interceptors, force mains, water transmission and distribution mains, pumping and lift stations, diversion and flow control structures, and/or tunnels and trenchless construction). 
  • Current Professional Engineer (PE) license. Licensure in Washington, DC, Maryland, or Virginia preferred; candidates eligible for licensure by reciprocity will be considered.  
  • Demonstrated experience serving as technical lead, project manager, or program manager on water or wastewater capital programs. 
  • Strong working knowledge of conveyance planning and design practice: hydraulic capacity evaluation, condition assessment, alternatives analysis, rehabilitation versus replacement strategy, pump station and force main design, and construction-phase engineering support.  
  • Experience performing independent technical review and QA/QC on engineering deliverables. 
  • Experience mentoring and reviewing the work of junior engineers. 
  • Strong client and agency-facing communication skills, with experience as the senior point of contact on a program or contract. 
  • Comfort building process and technical standards from the ground up. 

Preferred Qualifications: 
  • Master's degree in Civil Engineering, Environmental Engineering, or a related field.  
  • Experience supporting water resources and environmental infrastructure projects in the DC–Maryland–Virginia region.  
  • Experience with alternative delivery, including Progressive Design-Build and CMAR; DBIA certification. 
  • Direct experience coordinating with local, state, and federal regulatory agencies. 

Employment Conditions: 
  • Full-time, exempt employment. 
  • Work conditions & location: Regular presence at client and home office locations throughout the DC metro region. 

Physical Requirements:  
  • Must be able to perform essential duties satisfactorily with reasonable accommodation. 
  • Work is generally done sitting, talking, hearing, and typing. Visual acuity to use a keyboard, prepare and analyze data and figures; transcribing, viewing a computer terminal; extensive reading. 
  • Periodic site visits require the ability to traverse uneven terrain and active construction sites, wear personal protective equipment, and observe confined space and utility site safety protocols. 

Compensation & Benefits: 
  • Salary range: $150,000 – $190,000, commensurate with experience. 
  • Eligible for bonus. 
  • Eligible for-profit sharing. 
  • Medical, dental, and vision insurance. 
  • Retirement plan with 401(k) Safe Harbor employer match. 
  • Paid Time Off: up to 20 days per year, prorated during the first year of employment. 
  • Life insurance and disability insurance.  
  • Flexible spending accounts. 
  • Paid holidays and paid leave benefits. 

Must be legally authorized to work in the United States. InterAgency, Inc. is unable to provide employment visa sponsorship now or in the future for this position. 

InterAgency employment practices are in accordance with the laws that prohibit discrimination against qualified individuals on the basis of race, religion, color, gender, age, national origin, physical or mental disability, genetic information, veteran’s status, marital status, gender identity and expression, sexual orientation, or any other status protected by applicable law. 

InterAgency is an equal opportunity employer. 




Salary : $150,000 - $190,000

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