Maryland RegulationsIntermediate 25 min read

Maryland Water Distribution (WD): Operator Study Guide

A complete study guide for Maryland's single Water Distribution (WD) certification, covering the state's regulatory framework, major utilities, lead service line rules, and cross-connection control requirements.

Maryland Water Distribution (WD) Operator Study Guide

Overview

Maryland is unusual among states in having a single, ungraded certification class for water distribution operators: Water Distribution (WD). Unlike Maryland's five-tier Water Treatment ladder (Class G, D, 1-5), one WD certificate authorizes an operator to work on distribution systems of any size, from a small Eastern Shore town system to WSSC Water's vast Montgomery/Prince George's County network.

Regulatory Framework

Certifying body: The Board of Waterworks and Waste Systems Operators, under the Maryland Department of the Environment (MDE) Water Supply Program.
Governing regulation: COMAR 26.06.01 (operator certification).
Renewal cycle: 3 years, per COMAR 26.06.01.16, Table 8.
Plumbing code intersection: COMAR 26.04.01, the Maryland State Plumbing Code, governs cross-connection contro

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