---
title: "David B. Mason, Title 5 System Inspector SI #287 | Title 5 Roster"
description: "David B. Mason is a MassDEP-approved Title 5 System Inspector (SI #287) based in Barnstable, MA. Approval expires June 30, 2028 per the NEIWPCC list."
canonical: https://title5roster.com/inspectors/david-b-mason-si287/
---

# David B. Mason, Title 5 System Inspector (SI #287)

David B. Mason is on the NEIWPCC list of MassDEP-approved Title 5 System Inspectors dated October 2, 2026.

* **SI number:** #287
* **Approval expires:** June 30, 2028
* **Approved by:** Massachusetts Department of Environmental Protection (MassDEP); list published by NEIWPCC
* **Business listing:** Listed under own name
* **Based in:** Barnstable, MA
* **County:** Barnstable County

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