How to Use This Plumbing Resource

National Sewer Authority organizes licensed plumbing and sewer service professionals across the United States into a structured reference directory. This page describes how the directory is built, what categories of information it contains, and how to locate specific service types, geographic markets, or regulatory topics. The plumbing and sewer sector is governed by overlapping federal, state, and municipal frameworks — including the International Plumbing Code (IPC), the Uniform Plumbing Code (UPC), and state-level licensing boards — making reliable navigation of the service landscape a practical necessity for contractors, property owners, and facility managers alike.

What to look for first

The primary entry point for most users is the Sewer Listings section, which aggregates service providers by category and geography. Before drilling into specific listings, it is useful to understand how the directory classifies the plumbing sector, because not all plumbing work is legally or operationally equivalent.

The plumbing sector divides broadly into two regulatory lanes:

1. Licensed plumbing work — tasks requiring a state-issued master or journeyman plumbing license. This includes new water supply installations, drain-waste-vent (DWV) system modifications, gas line work, and backflow prevention assembly. Forty-six states plus the District of Columbia maintain mandatory plumbing licensing at the state or local level, enforced through boards such as the Texas State Board of Plumbing Examiners or the California Contractors State License Board.
2. Drain and sewer service work — tasks that may or may not require a plumbing license depending on jurisdiction, including hydro-jetting, sewer camera inspection, trenchless pipe rehabilitation (CIPP lining), and septic system pumping. This category intersects with environmental regulations enforced by the U.S. Environmental Protection Agency under the Clean Water Act.

Identifying which lane applies to a service need determines the correct credential to verify and the correct regulatory body to consult.

How information is organized

The directory is structured around 4 primary classification axes:

1. Service category — drain cleaning, sewer line repair, trenchless rehabilitation, septic service, water main work, and backflow testing each represent distinct professional scopes with different licensing thresholds.
2. Geographic market — listings are indexed at the state level, with metro-area subdivisions for the 30 largest U.S. urban markets. Regulatory requirements vary materially by state; California, Florida, and New York each maintain separate plumbing licensing structures that differ from IPC-adopting states.
3. License classification — entries distinguish between master plumbers, journeyman plumbers, specialty drain contractors, and licensed septic system contractors. These are not interchangeable categories; a licensed drain contractor in one state may not hold qualifications equivalent to a journeyman plumber in another.
4. Permit and inspection relevance — service types that universally require a pulled permit (such as water heater replacement or sewer lateral replacement) are flagged separately from service types that typically do not (such as drain cleaning or video inspection).

The Directory Purpose and Scope page provides fuller detail on the inclusion criteria applied to listings and the verification methodology used to classify license types.

Limitations and scope

This directory covers the continental United States. Hawaii and Alaska are included in state-level indexes but have lower listing density given population distribution and contractor availability patterns.

The directory does not serve as a licensing verification system. Plumbing license status is a live record held by state licensing boards; the authoritative verification source for any given contractor is the relevant state board database — for example, the Florida Department of Business and Professional Regulation for Florida-licensed plumbers, or the Illinois Department of Public Health for plumbing-regulated work in that state.

Permit requirements are not uniform. A sewer lateral repair that requires a permit in Chicago may be performed without one in a rural county in the same state. The directory flags permit-relevant service categories but does not adjudicate whether a specific project in a specific jurisdiction requires a permit. That determination rests with the applicable authority having jurisdiction (AHJ), as defined under the IPC and UPC adoption frameworks.

The directory also does not cover:
- Emergency dispatch services
- Plumbing supply and materials vendors
- Engineering and design-only firms without field service operations
- HVAC or mechanical contractors whose scope does not include plumbing under state definitions

How to find specific topics

The directory supports navigation through three access paths:

By service type — Users seeking a specific service (hydro-jetting, pipe bursting, CIPP lining, grease trap cleaning) should use the service category index within Sewer Listings. Each category page identifies the applicable license tier, common permit requirements, and the distinction between residential and commercial service providers in that category.

By geography — State and metro landing pages aggregate all listed contractors operating in that market, sorted by license classification. Because plumbing codes differ between IPC-adopting and UPC-adopting states — the UPC is predominant across 35 states in the western and southern United States while the IPC is the adopted model code in most of the eastern United States — geographic filtering surfaces contractors credentialed under the applicable local code framework.

By regulatory or standards topic — For users researching code requirements, permitting structures, or inspection standards, the reference section addresses specific regulatory frameworks including IAPMO's Uniform Plumbing Code, the International Code Council's IPC, NSF/ANSI 61 standards for drinking water system components, and OSHA's sanitation standards under 29 CFR 1910.141. The How to Use This Sewer Resource page is the companion navigation reference for the broader sewer sector index.

Cross-referencing service type with geographic market and license classification produces the most precise results for identifying qualified contractors operating within the correct regulatory jurisdiction for a given project type.