Which wage determination applies to my project in Williamson County?

The wage determination incorporated into your contract is the one that governs, per 29 CFR 1.6. For new heavy work in Williamson County, IL, the current active determination is IL20260018. Verify with your contracting officer before bidding or paying.

How often do these rates change?

DOL publishes wage determination modifications weekly, generally on Fridays. The determination behind this page was last modified July 30, 2026.

What is the difference between the base rate and the fringe rate?

The base rate is the minimum hourly wage; the fringe amount is an additional hourly benefit obligation you can meet with bona fide benefit contributions or pay in cash. On this schedule the median fringe is about 62% of base.

My classification is not listed for Williamson County. What do I do?

If the work classification you need is not on the determination, the contractor requests a conformance (additional classification and rate) through the contracting agency using Standard Form 1444. Do not substitute a similar-sounding classification.

What counts as heavy construction?

Heavy covers projects that are not building, residential, or highway, such as water and sewer lines, dams, and flood control. Agencies sometimes split it further; the contract states which schedule applies.

Does the federal rate or the Illinois state prevailing wage apply?

They are separate systems. Davis-Bacon rates apply to federally funded or assisted work; a state prevailing wage law can apply to state-funded work. A project can be covered by both, in which case the higher rate for each classification effectively controls. This page shows the federal determination only.

Is the WH-347 form mandatory?

The WH-347 itself is optional; what is mandatory on covered work is submitting weekly certified payroll with the same information and a signed Statement of Compliance. Most contractors use the WH-347 layout because agencies expect it.

PREVAILWAGE

Pulling the rate table…

Heavy prevailing wage rates for Williamson County, IL | PrevailWage

Heavy prevailing wage rates for Williamson County, IL

DOL marked wage determination IL20260016 modified July 30, 2026 (revision 2). Verify against the source below before filing.

DOL modified the wage determination for heavy work in Williamson County, IL within the last 30 days. The active federal wage determinations covering heavy construction in Williamson County, IL list 104 classifications with published rates, base pay from $25.25 to $65.52 per hour. The determination was last modified July 30, 2026.

Classifications: 104; with published rates
Median base: $41.88; per hour
Median fringe: 62%; of base pay
Last modified: July 30, 2026

Published rates

Classification	Base	Fringe	WD
CARPENTER(CRAWFORD, EFFINGHAM, AND JASPER COUNTIES)	$33.54	$27.97	IL20260016
CARPENTER(CLAY, EDWARDS, FAYETTE, LAWRENCE, MARION, RICHLAND, AND WABASH COUNTIES)	$39.02	$18.90	IL20260016
CARPENTER(HAMILTON, JEFFERSON, WAYNE, AND WHITE COUNTIES) DIVERS (RECEIVE 1 1/2 TIMES CARPENTER RATE PLUS FRINGES AND $25 PER DAY FOR EQUIPMENT)	$39.02	$18.90	IL20260016
CARPENTER

The governing determination was modified July 30, 2026, within the last 30 days. Contractors mid-bid in Williamson County should re-check figures against the determination text before submitting.

With 104 classifications carrying published rates, this is a comparatively deep schedule; most trades a heavy project needs appear without a conformance request.

100% of the rate lines here carry union local identifiers, so the published figures track negotiated agreements, which is why some classifications carry high fringe amounts relative to base.

Using these rates

Read the modification number

A wage determination is cited as number plus modification, for example IL20260018 Mod dated July 30, 2026. Your certified payroll should reflect the determination in your contract, not necessarily the newest one.

Put the WD in your bid file

Save the full determination text with your bid papers the day you price the job. If rates change later, the contract determination is your record of what you bid against.

Check rates the Friday before payroll

DOL publishes modifications weekly, generally Fridays. A quick check before running payroll catches a mid-project modification before it shows up in an agency review instead.

Match classifications by duties, not titles

The classification that applies is determined by the work performed, not the worker's title. A foreman who works with the tools is generally due the rate for the hours on the tools.

Fringe crediting basics

You can meet the fringe obligation with bona fide benefit plan contributions, cash, or a combination. Track the hourly equivalent of what you contribute; agencies ask for the math.

Statement of Compliance wording

The signed Statement of Compliance may be the WH-347 back page or another document with identical wording. The signature is a federal certification by your company's officer; accuracy is on the certifier.

Questions

Which wage determination applies to my project in Williamson County?: The wage determination incorporated into your contract is the one that governs, per 29 CFR 1.6. For new heavy work in Williamson County, IL, the current active determination is IL20260018. Verify with your contracting officer before bidding or paying.
How often do these rates change?: DOL publishes wage determination modifications weekly, generally on Fridays. The determination behind this page was last modified July 30, 2026.
What is the difference between the base rate and the fringe rate?: The base rate is the minimum hourly wage; the fringe amount is an additional hourly benefit obligation you can meet with bona fide benefit contributions or pay in cash. On this schedule the median fringe is about 62% of base.
My classification is not listed for Williamson County. What do I do?: If the work classification you need is not on the determination, the contractor requests a conformance (additional classification and rate) through the contracting agency using Standard Form 1444. Do not substitute a similar-sounding classification.
What counts as heavy construction?: Heavy covers projects that are not building, residential, or highway, such as water and sewer lines, dams, and flood control. Agencies sometimes split it further; the contract states which schedule applies.
Does the federal rate or the Illinois state prevailing wage apply?

Sources

IL20260018 rev. 2 · modified June 17, 2026
IL20260019 rev. 1 · modified May 18, 2026
IL20260016 rev. 2 · modified July 30, 2026

Synced from SAM.gov August 1, 2026. The wage determination incorporated into your contract is the legally operative document.