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Send resume and cover letter to lcarlsson-irwin@irwinengineers.com


IRWIN Engineers is a boutique chemical and environmental engineering firm specializing in hard to solve situations. We have a staff of highly talented people who enjoy challenge, responsibility, variety, client contact and knowing their work has a real positive impact.

Our firm is seeking motivated individuals interested in the areas of environmental engineering and compliance consulting. Project work includes: process engineering; project permitting (air, water, wastewater); multimedia auditing; site assessment; and design of pollution control and remediation systems. Typical compliance programs are: air pollution control, wastewater treatment, hazardous waste management, Spill Prevention Control & Countermeasures, Toxics Use Reduction Planning, and Process Safety Management.

Suitable candidates must have: a BS and/or Masters in chemical or environmental engineering with a GPA of 3.1 or above, 1-3 years of experience, strong project management skills and an excellent command of written and spoken English.  Must be able to multi-task, be detail oriented and a self-starter. Desirable skills include drafting experience and 40 hours HAZWOPER training. This position has a mix of office and job-site work. In the course of a week you may spend time writing proposals and reports, supervising sub-contractors at a job-site, conducting sampling of various media outside or inside, talking to clients, subs and vendors, attending meetings, conducting research and reporting to supervisors. Time will be spent working both solo and with others. Successful candidates will be people who enjoy challenge, embrace lifelong learning, are not afraid to do new things and sometimes apply some elbow grease as well as brain power to a problem. The position includes the opportunity for very early client contact for those with good interpersonal skills. We deal with a wide variety of people and circumstances and hold professionalism as a key employee attribute. Finally, while we expect plenty of hard work, we believe it is important to have a healthy work-life balance.

We are located in the New England town of Natick in Metrowest Boston.  Our firm is housed in a National Historic Register building within an easy walk to town center. We are a group of bright, hardworking, fun-loving people who place a value on being consummate professionals. We love to solve problems that others can’t. We are looking for likeminded individuals who want to be creative with their engineering and make a career of consulting.


2022-August Regulatory News

2021-November Regulatory News
2019-October Regulatory News
2019-July Regulatory News

Regulatory Summary: for recent newsletter click here: 2022-August Regulatory News

Highlight Table of Contents:

  1. Regulatory Actions Under TSCA


      2. Upcoming Deadline for Waste Disposal Ban Compliance

3. Upcoming Cumulative Impact Analysis Requirements for New or Modified Air Permit Applications

Massachusetts & New Hampshire

4. Draft NPDES Dewatering and Remediation General Permit Available

IRWIN News Please read about our remediation project under Sample Projects

See the write-up at the end of the April 2019 newsletter.


Patent granted for: Rapid Perchlorate Destruction in Soil and Groundwater Through Bioaugmentation

IRWIN, together with its co-inventor, has proven that perchlorate contamination can be successfully treated using a new patented process. By adding a registered strain of facultative bacteria, nutrients and appropriate buffering IRWIN showed that even high levels of perchlorate can be rapidly reduced in situ in soil and groundwater. Perchlorate, a propellant used in flares, rockets and fireworks, is a contaminant at more than 400 sites across the United States. To date, in-situ biological treatment of perchlorate has been attempted with anaerobic species using various carbon substrates with limited success. Irwin Engineers Perchlorate Treatment Case Study



IRWIN Engineers helped a fiber-optic glass manufacturer permit a major upgrade to their industrial wastewater pretreatment system that had been in operation for over 30 years without a shutdown of plant operations during the construction.

The aging system could no longer process wastewater at its design flow rate. The waste contained a high fraction of coarse solids that settled so densely in the clarifier that the sludge was very difficult to remove.  IRWIN performed field experiments using a novel treatment technique that used hydrocyclone units (Figure 1) to remove the coarse solids from the wastewater before the clarifier.  The system also chronically overdosed treatment chemicals used to remove heavy metals based on the dosing control scheme.  Through a revised control scheme, and addition of a precipitation aid, chemical usage for precipitation will be reduced by over 50 percent.  The new design allowed the facility to reduce the footprint of the clarifier and precipitation systems by half (Figure 2).  Rather than replacing the existing rotary vacuum sludge dewatering system, value was found with targeted part replacements to extend the equipment life.  Those changes and operator training decreased sludge dewatering processing time by over 65%.

Figure 1: Hydrocyclone

 Figure 2: Precipitation and Clarification System

The system was equipped with new controls providing increased automation, stability, and reliability, and a new HMI with a touchscreen and wireless connectivity, reducing the operator attention and time required to run the system. IRWIN coordinated with the contractor throughout the construction phase implementing temporary systems to avoid interrupting the incoming flow of process wastewater. IRWIN also provided support during the startup of the system, visiting the site to perform testing, assist with troubleshooting, and confirm performance of the new system.

The result of IRWIN’s creative problem solving and hands-on approach is a treatment system that processes wastewater four times faster than the original system, uses significantly less treatment chemistry, produces less than half as much solid hazardous waste, and reduced operating labor costs by 70 percent.


2016 was another successful Toxic Use Reduction Filing year

Andy Irwin, PE, LSP, TURP, CPEA is certified for TUR Plans and Resource Conservation Plans. He is a BEAC Certified Professional Environmental Auditor ISO14000 Plus. He is a former President, Treasurer and Board Member of the Toxics Use Reduction Planners Association
The TURA program is intended to facilitate and encourage pollution prevention opportunities by evaluating operations and identifying feasible options for reducing the use of toxics. Facility personnel, along with a certified TUR Planner, work to identify TUR options and evaluate them for their technical and economic feasibility.  In many cases, we have found that implementing various TUR opportunities not only reduced the amount of toxics used, but also reduced costs and improved efficiency for our clients.

Project Examples

We serve a wide range of industries including:

For more information visit,

IRWIN Engineers Pollution Prevention & Toxic Use Reduction

IRWIN Engineers Auditing

Massachusetts DEP TURA Program Overview