New York Wastewater Operator Certification: Grades 1-4A
New York certifies wastewater treatment plant operators through the Department of Environmental Conservation (DEC), under 6 NYCRR Part 650. That's a different agency from the Department of Health, which handles drinking water, and the two programs don't line up. Day to day, applications and renewals are handled by the New York Water Environment Association (NYWEA) on DEC's behalf. Here's how it works.
Requirements and fees change. Always confirm the current details on DEC's operator certification page and in NYWEA's certification manual before you apply. This guide is an overview, not the rulebook.
Key takeaways
- Grades run 1 to 4 (4 is highest). An A grade (1A to 4A) adds activated sludge, and an A holder can run either kind of plant.
- Every grade needs a high-school diploma, plant experience and DEC-approved training.
- The exam is the WPI exam on computer at PSI test centers, with 70% to pass.
- Certificates renew every 5 years, with 20, 40, 60 or 80 contact hours depending on your grade.
- Practice with the free New York tests, starting with Wastewater Class 1.
Step 1: Know which grade your plant needs
DEC scores every plant on its design flow (3 points per MGD, up to 50) plus points for each treatment process (plant score sheet). The score sets the grade the chief operator and assistant need:
| Plant score | Chief operator | Assistant |
|---|---|---|
| 30 or less | 1 / 1A | 1 / 1A |
| 31 to 55 | 2 / 2A | 1 / 1A |
| 56 to 75 | 3 / 3A | 2 / 2A |
| 76 and up | 4 / 4A | 3 / 3A |
At an activated sludge plant you need the A version of the grade. DEC can require a higher grade than the table shows.
Step 2: Meet the requirements
All grades need a high-school diploma or equivalent. Training builds as you go: a Grade 4 applicant also has to complete the Grade 2 and 3 training.
| Grade | Plant experience | Training |
|---|---|---|
| 1 / 1A | 6 months at any permitted plant (1A: an activated sludge plant) | Basic Operations, or an approved home-study course |
| 2 / 2A | 1 year at a plant scoring 31+ | Basic Operations (60 hours) plus a lab requirement (a 30-hour lab course, the lab exam, or lab-tech experience) |
| 3 / 3A | 1.5 years at a plant scoring 56+ | Grade 3 Supervision & Technical Operations course |
| 4 / 4A | 2 years at a plant scoring 76+ | Grade 4 Management course (no home-study option) |
Total experience at Grades 3 and 4 depends on your education. Grade 3 needs 4.5 years with a high-school diploma, 3 years with an associate degree (with 30 math or science credits), or 1.5 years with a DEC-approved associate or a bachelor's. Grade 4 needs 8 years with high school, 5 with an associate, 3.5 with an approved associate, or 2 with a bachelor's (30 math or science credits).
For the A grades, add a 24-hour activated sludge course, and your experience must be at an activated sludge plant. At least half of your experience must be hands-on operation. Time at pretreatment plants, in collection systems or at water plants doesn't count.
Step 3: Take the exam
You apply through NYWEA, then take the WPI exam on computer at a PSI test center:
- 100 questions for Grades 1, 2, 3, 4 and 4A. 110 for 1A, 2A and 3A, where 10 are unscored.
- 3 hours, with a formula sheet provided. Bring a non-programmable calculator.
- 70% to pass, scored on the spot.
- Fees: $195 to NYWEA for the application, plus $112 to PSI.
- If you fail, you wait at least 90 days and pay PSI's $112 again.
The free wastewater math practice test and math formulas guide cover the calculations.
Step 4: Renew every 5 years
Certificates renew every 5 years, and you can apply up to 90 days before they expire. Contact hours per cycle:
- Grade 1 / 1A: 20
- Grade 2 / 2A: 40
- Grade 3 / 3A: 60
- Grade 4 / 4A: 80
For certificates expiring from 2027, those totals must include cybersecurity training: 2 hours for Grades 1 and 2, and 4 hours for Grades 3 and 4. Renewal costs $205, plus a $50 late fee.
There's no grace period. An expired certificate means you're no longer certified. Within a year of expiring you can reinstate it without retesting. After a year, you complete the hours, pay both fees and take the exam again.
Moving to New York with a license
New York has no formal reciprocity agreement. It accepts WPI (formerly ABC) exam results, but out-of-state operators still have to meet New York's education and training requirements. Ask NYWEA before you assume anything transfers.
Next steps
- Check current rules on DEC's operator certification page and NYWEA's certification manual.
- Practice: Grade 1, Grade 2, Grade 3, Grade 4, plus activated sludge for the A grades. Or try the New York wastewater flashcards.
- Working on the water side too? See how to become a water operator in New York.
Sources: 6 NYCRR Part 650 (via DEC TOGS 5.1.6); DEC operator certification page and cybersecurity fact sheet (2026); NYWEA Certification Manual (rev. December 2024). Reviewed October 2026.