---
title: "Adam R. Riker, Title 5 System Inspector SI #4590 | Title 5 Roster"
description: "Adam R. Riker is a MassDEP-approved Title 5 System Inspector (SI #4590) based in Yarmouth, MA. Approval expires June 30, 2027 per the NEIWPCC list."
canonical: https://title5roster.com/inspectors/adam-r-riker-si4590/
---

# Adam R. Riker, Title 5 System Inspector (SI #4590)

Adam R. Riker is on the NEIWPCC list of MassDEP-approved Title 5 System Inspectors dated October 2, 2026.

* **SI number:** #4590
* **Approval expires:** June 30, 2027
* **Approved by:** Massachusetts Department of Environmental Protection (MassDEP); list published by NEIWPCC
* **Business listing:** Listed under own name
* **Based in:** Yarmouth, MA
* **County:** Barnstable County

Source: https://neiwpcc.org/wp-content/uploads/2026/10/SI-Instate-10.2.2026.pdf (retrieved 2026-10-12)