v. Colorado State Bd. of Plumbing, 2020 COA 130

In 2016 a plumbing apprentice employed by Confidence Plumbing used a soldering torch inside an unfinished house in a master-planned community; a city inspector observed the apprentice working without a licensed plumber in the same house and filed a complaint.
§ 12-155-124 requires plumbing apprentices to work “under the supervision of a licensed plumber” and that “supervision requires that a licensed plumber supervise apprentices at the job site,” but the statute does not define “supervision” or “job site.”
An ALJ found Welch and Confidence violated § 12-155-124, concluding the statute requires line-of-sight supervision and that “job site” meant the same building; the ALJ imposed probation and a $500 fine.
The Colorado State Plumbing Board adopted the ALJ’s interpretation, increased sanctions (five-year suspensions and a $2,300 fine), and declined to rule on the statute’s constitutionality.
Welch and Confidence appealed, arguing the statute is void for vagueness and does not require line-of-sight supervision.
The Court of Appeals held the statute ambiguous but constitutionally salvageable, construed “supervise apprentices at the job site” to mean reasonable proximity to monitor, inspect, and sign off with reasonable frequency (not line-of-sight), found Welch compliant, and vacated the Board’s order.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether § 12-155-124 is unconstitutionally vague	Welch: undefined terms (“supervision,” “job site”) fail to give fair notice	State: statute is valid and can be construed to provide notice	Not void for vagueness; statute is ambiguous but capable of a constitutional construction
Whether the statute requires line-of-sight supervision / “job site” = same building	Welch: statute does not demand line-of-sight or same-building presence	Board: supervision requires line-of-sight and job site means the same building	Rejected the Board: statute does not require line-of-sight; “supervise at the job site” means supervisor must be within sufficient distance (in or outside a building) to monitor, inspect, and sign off with reasonable frequency
Whether Welch and Confidence violated § 12-155-124 on these facts	Welch: supervising journeyman was on the broader job site, inspected and signed off; so compliance	AG/Board: apprentice was unsupervised in the house and statute violated	Under the court’s construction, Welch complied; Board’s sanctions vacated

People v. Zapotocky, 869 P.2d 1234 (Colo. 1994) (ambiguities in statutes should be construed to preserve constitutionality)
Holcomb v. Jan-Pro Cleaning Sys., 172 P.3d 888 (Colo. 2007) (agency may not add or subtract statutory language in its interpretation)
State v. Nieto, 993 P.2d 493 (Colo. 2000) (statute read as a whole to give consistent, sensible effect)
Auman v. People, 109 P.3d 647 (Colo. 2005) (omissions in statutory language are informative to legislative intent)
Evans v. City & County of Denver, 247 P. 173 (Colo. 1926) (dictum: apprentices need not labor under the constant eye of the master if master’s direction appears in the work)
Capital Elec. Line Builders of Kan., Inc. v. Marshall, 678 F.2d 128 (10th Cir. 1982) (practical limits on requiring constant physical accompaniment or line-of-sight supervision)
Horne Plumbing & Heating Co. v. Occupational Safety & Health Review Comm’n, 528 F.2d 564 (5th Cir. 1976) (courts refuse to require unreasonable or infeasible supervisory measures)