SUMMARY

August 27, 2020

2020COA130

No. 19CA1144, Welch v. Colorado State Bd. of Plumbing —

Professions and Occupations — Plumbers — Apprentices; 

Constitutional Law — Due Process 

A division of the court of appeals considers whether section 

12-58-117, C.R.S. 2018, repealed and replaced by section 12-155-

124, C.R.S. 2019, of the Plumbing Practice Act is unconstitutionally 

vague and, in doing so, applies principles of statutory construction 

to determine whether the statute requires line-of-sight supervision 

of plumbing apprentices at the job site. The division concludes that 

section 12-155-124 is not void for vagueness because the terms 

here challenged, although ambiguous, are capable of a 

constitutional construction. Because the division concludes that 

section 12-155-124 only requires that a licensed plumber 

supervising apprentices be within a sufficient distance of the 

The summaries of the Colorado Court of Appeals published opinions 

constitute no part of the opinion of the division but have been prepared by 

the division for the convenience of the reader. The summaries may not be 

cited or relied upon as they are not the official language of the division. 

Any discrepancy between the language in the summary and in the opinion 

should be resolved in favor of the language in the opinion.
apprentice, whether in or outside a building, in order to monitor, 

inspect, and sign off on the apprentice’s work with reasonable 

frequency, the division vacates the Board’s order.
COLORADO COURT OF APPEALS 2020COA130

Court of Appeals No. 19CA1144

Colorado State Plumbing Board Nos. 2016-1285 & 2016-2488

Michael E. Welch and Confidence Plumbing Co., Inc.,

Appellants,

v.

Colorado State Plumbing Board,

Appellee.

ORDER VACATED

Division II

Opinion by JUDGE PAWAR

Román and Tow, JJ., concur

Announced August 27, 2020

Springer and Steinberg, P.C., Jeffrey A. Springer, Aaron C. Acker, Craig L. 

Pankratz, Denver, Colorado, for Appellants

Philip J. Weiser, Attorney General, Cristel Shepherd, Assistant Attorney 

General, Denver, Colorado, for Appellee
1

¶ 1 In this appeal from an agency hearing, we consider, for the 

first time, whether the Plumbing Practice Act requires “line-of-sight” 

supervision of an apprentice plumber. As necessarily interrelated 

with that inquiry, we determine what supervision “at the job site” 

means in the same statute. Applying principles of statutory 

construction, we conclude that the statute does not require 

line-of-sight supervision, and that to “supervise apprentices at the 

job site” requires that a licensed plumber be within a sufficient 

distance of the apprentice, whether in or outside a building, in 

order to monitor, inspect, and sign off on the apprentice’s work with 

reasonable frequency.

I. Procedural Background

¶ 2 Confidence Plumbing Co., Inc. (Confidence) and its owner,

Michael E. Welch, appeal the order of the Colorado State Plumbing

Board (Board) disciplining them for violations of the Plumbing 

Practice Act. §§ 12-58-101 to -117, C.R.S. 2018, repealed and 
2

replaced by §§ 12-155-101 to -124, C.R.S. 2019.1 The Board2 found 

that Mr. Welch and Confidence violated section 12-155-124, C.R.S. 

2019, by allowing a plumbing apprentice to use a soldering torch 

without having line-of-sight supervision from a licensed plumber. 

As a result, the Board imposed a $2300 fine against Mr. Welch and 

Confidence, suspended Mr. Welch’s journeyman and master 

plumber licenses for five years, and suspended Confidence’s 

plumbing contractor registration for five years. On appeal, Mr. 

Welch and Confidence challenge the constitutionality of section 

12-155-124, as well as the Board’s adoption of the interpretation of 

the Administrative Law Judge (ALJ) that “supervision” under that 

section requires line-of-sight oversight of apprentices at the job site.

 

1 In particular, section 12-58-117, C.R.S. 2018, was relocated to 

section 12-155-124, C.R.S. 2019, with only minor nonsubstantive 

changes that are not relevant to this dispute. Ch. 136, sec. 1, 

§ 12-155-124, 2019 Colo. Sess. Laws 1010. 2 We note that the Board (through the Attorney General) is both the 

petitioner that prosecuted enforcement before the administrative 

law judge, as well as the reviewing entity (through the Board’s 

conflicts program director) that issued the final order on appeal. 

While this is the normal procedure, we attempt to minimize 

confusion by referring to the petitioner as the Attorney General and 

the reviewing entity as the Board.
3

¶ 3 Though we disagree with Mr. Welch and Confidence that 

section 12-155-124 is unconstitutional, we agree that the Board 

incorrectly interpreted section 12-155-124 in applying it to Mr. 

Welch’s conduct. We therefore vacate the Board’s order.

II. Relevant Facts

¶ 4 In 2016, a plumbing apprentice working for Confidence 

performed plumbing work in an unfinished house that was part of a 

master-planned community in Aurora, Colorado. Pursuant to the 

Plumbing Practice Act, a registered plumbing apprentice may 

perform plumbing work without a license, provided that he or she is 

“under the supervision of a licensed plumber.” § 12-155-124(1). 

“Supervision requires that a licensed plumber supervise apprentices 

at the job site.” Id.

¶ 5 A building inspector for the city of Aurora saw the apprentice 

using a soldering torch on a domestic water line. The inspector also 

saw that a licensed plumber was not in the house with the 

apprentice. Based on his observations, the building inspector filed 

a complaint with the Board, alleging that Mr. Welch and Confidence 

had engaged in “unlicensed practice.” In a response to the 

complaint, Mr. Welch stated:
4

[W]e did and do have a licensed supervisor on 

the jobsite when plumbing installations are 

performed. It should be noted, however, that a 

jobsite is not just one building in residential 

construction, but several homes located in a 

larger community. The supervisor may not 

have been in that particular home at the time 

of the complaint, but he was on site.

¶ 6 Upon referral from the Board, the Attorney General filed a 

petition with the Office of Administrative Courts, charging Mr. 

Welch and Confidence with failing to supervise the apprentice in 

violation of section 12-155-124.3 The petition requested that (1) Mr. 

Welch’s journeyman and master plumber licenses be placed on 

probation for five years; (2) Confidence’s contractor registration be 

placed on probation for five years; and (3) Mr. Welch and 

Confidence pay a fine of $2300. See § 12-58-110, C.R.S. 2018, 

repealed and replaced by § 12-155-113, C.R.S. 2019.

¶ 7 The ALJ held a hearing on the petition. Several witnesses 

testified regarding supervision of plumbing apprentices at job sites,

including Mr. Welch, the building inspector, a journeyman plumber 

 

3 The petition included an additional charge against Mr. Welch and 

Confidence for failing to supervise a different plumbing apprentice, 

but the ALJ found that the Attorney General failed to prove its 

allegations as to that charge. That charge is not at issue on appeal.
5

and former Confidence employee, and the Board’s program director. 

The ALJ also heard evidence regarding a citation brought against 

Mr. Welch and Confidence several years earlier for failure to 

supervise an apprentice on two separate occasions that resulted in 

a stipulation in which Mr. Welch and Confidence agreed to a fine.

¶ 8 The ALJ issued an initial decision order, finding that Mr.

Welch and Confidence violated section 12-155-124. The ALJ 

specifically concluded that section 12-155-124 requires licensed 

plumbers to maintain line-of-sight supervision over apprentices 

using soldering torches and that “job site” means the same building 

in which the apprentice is working. In so concluding, the ALJ cited 

the testimony from Confidence’s former employee as particularly 

persuasive regarding line-of-sight supervision for apprentices using 

soldering torches.

¶ 9 The ALJ did not impose the sanctions requested in the 

petition, however, finding them “too harsh.” Instead, the ALJ 

placed Mr. Welch’s master and journeyman plumber licenses and 

Confidence’s contractor registration on probation for one year and 

imposed a $500 fine, pursuant to section 12-155-113.
6

¶ 10 Mr. Welch and Confidence, as well as the Attorney General, 

filed exceptions to the ALJ’s initial order. The Attorney General 

modified the originally requested sanctions, seeking instead to 

suspend Mr. Welch’s plumber licenses and Confidence’s contractor 

registration for one year, in lieu of placing them on probation. Mr. 

Welch and Confidence responded that section 12-155-124 is 

unconstitutionally vague; section 12-155-124 does not require 

line-of-sight supervision; and the ALJ improperly relied on the 

former employee’s testimony in interpreting the statute.

¶ 11 In its final order, the Board adopted the ALJ’s findings of 

evidentiary fact and ultimate conclusions, determining that section 

12-155-124 requires line-of-sight supervision at the job site over

apprentices using soldering torches. However, the Board declined 

to resolve the meaning of “job site,” noting that “there was no need 

for the Administrative Court to determine whether a ‘jobsite’ is a 

single house identified on a permit or a group of homes in a 

development — either way line-of-sight supervision is required while 

an apprentice solders a domestic water line.” The Board also found 

that it lacked jurisdiction to address Mr. Welch and Confidence’s 

constitutional challenge to section 12-155-124. Citing Mr. Welch
7

and Confidence’s prior offense for failing to supervise an apprentice, 

as well as the “high potential for fire when soldering with a torch,”

the Board determined that harsher sanctions were warranted than 

those the ALJ had imposed. It suspended Mr. Welch’s master and 

journeyman plumber licenses and Confidence’s contractor 

registration for five years and imposed a $2300 fine.

¶ 12 Mr. Welch and Confidence appeal the Board’s final order,

contending that (1) section 12-155-124 is unconstitutionally void 

for vagueness; (2) the Board erred by adopting the ALJ’s

interpretation of section 12-155-124 to require line-of-sight 

supervision when apprentices use soldering torches; and (3) the 

Board erred by determining that the ALJ properly relied on 

Confidence’s former employee’s testimony as the basis for her

interpretation of the statute. We disagree with Mr. Welch and 

Confidence’s claim that the statute is unconstitutionally vague. We 

agree, however, that the Board erroneously interpreted the statute. 

Because we vacate the order, we need not address Mr. Welch and 

Confidence’s third contention. 
8

III. Section 12-155-124 Is Not Void for Vagueness

¶ 13 Mr. Welch and Confidence contend that section 12-155-124

violates due process and must be declared void because it contains 

impermissibly vague terms and standards. They argue that section 

12-155-124 is vague because it fails to clearly define “supervision,”

“job site,” and “supervise apprentices at the job site,” leaving 

plumbing licensees without appropriate guidance for the 

supervision of apprentices. We conclude that section 12-155-124 is 

not void for vagueness because the challenged terms, although 

ambiguous, are capable of a constitutional construction.

A. Jurisdiction

¶ 14 Administrative agencies do not have the authority to determine 

the constitutionality of statutes they are charged with enforcing. 

Arapahoe Roofing & Sheet Metal, Inc. v. City & Cty. of Denver, 831 

P.2d 451, 454 (Colo. 1992). “That function may be exercised only 

by the judicial branch of government.” Id. In cases involving direct 

review of agency action, the court of appeals has initial jurisdiction 

to review the constitutionality of a statute. Celebrity Custom 

Builders v. Indus. Claim Appeals Office, 916 P.2d 539, 541 (Colo. 

App. 1995).
9

B. Burden of Proof and Standard of Review

¶ 15 In determining the constitutionality of a statute, we begin with 

the presumption that the statute is valid. Coffman v. Williamson, 

2015 CO 35, ¶ 13. The burden is on the party challenging the 

statute to prove it is unconstitutional beyond a reasonable doubt. 

Id. Statutory terms should be construed in a manner that 

preserves the statute’s constitutionality. People v. Zapotocky, 869 

P.2d 1234, 1240 (Colo. 1994). If the statute is capable of multiple 

constructions, one of which is constitutional, the constitutional 

interpretation should be adopted. Id.

¶ 16 We review an agency’s statutory interpretation de novo. 

Lobato v. Indus. Claim Appeals Office, 105 P.3d 220, 223 (Colo. 

2005). We may defer to the agency’s interpretations of its governing 

statutes, but “we ‘are not bound by an agency decision that 

misapplies or misconstrues the law.’” Welby Gardens v. Adams Cty. 

Bd. of Equalization, 71 P.3d 992, 1000 (Colo. 2003) (quoting El Paso 

Cty. Bd. of Equalization v. Craddock, 850 P.2d 702, 704-05 (Colo. 

1993)). The agency’s reading of a statute cannot alter the statutory 

language by adding or subtracting words. Holcomb v. Jan-Pro 

Cleaning Sys., 172 P.3d 888, 894 (Colo. 2007).
10

¶ 17 Our primary task in construing a statute is to ascertain and 

give effect to the intent of the legislature. People v. Iannicelli, 2019 

CO 80, ¶ 19. To determine legislative intent, we look first to the 

plain language of the statute, giving the words their common 

meanings. Id. We must read and consider the statute as a whole 

“to give consistent, harmonious, and sensible effect to all its parts.” 

State v. Nieto, 993 P.2d 493, 501 (Colo. 2000) (quoting People v. 

Dist. Court, 713 P.2d 918, 921 (Colo. 1986)). And we must avoid 

statutory constructions that would lead to illogical or absurd 

results. Iannicelli, ¶ 20.

¶ 18 If the statutory language is clear and unambiguous, we must 

interpret the statute as written. Zapotocky, 869 P.2d at 1238. If, 

however, the intended meaning of the statutory language is unclear 

and the statute is capable of more than one reasonable 

construction, the statute is considered ambiguous, and we may 

apply a body of accepted intrinsic and extrinsic aids in order to 

discern legislative intent. Id.; see also Holcomb, 172 P.3d at 890. 

Such interpretive aids include “[t]he common law or former 

statutory provisions, including laws upon the same or similar 

subjects”; the legislative declaration and purpose of the statute; and 
11

the consequences of a particular interpretation. § 2-4-203(1)(d), 

C.R.S. 2019; Gallion v. Colo. Dep’t of Revenue, 171 P.3d 217, 221-22 

(Colo. 2007).

C. Analysis 

1. Section 12-155-124 Is Ambiguous 

¶ 19 A “[p]lumbing apprentice” is “any person, other than a master, 

journeyman, or residential plumber, who, as his or her principal 

occupation, is engaged in learning and assisting in the installation 

of plumbing.” § 12-155-103(9), C.R.S. 2019. The Plumbing 

Practice Act requires that apprentices be supervised by licensed 

plumbers.

Any person may work as a plumbing 

apprentice for a registered plumbing 

contractor but shall not do any plumbing work 

for which a license is required pursuant to this 

article 155 except under the supervision of a 

licensed plumber. Supervision requires that a 

licensed plumber supervise apprentices at the 

job site. One licensed journeyman plumber, 

master plumber, or residential plumber shall 

not supervise more than three apprentice 

plumbers at the same job site.

§ 12-155-124(1). A plumber charged with supervising an 

apprentice is responsible for the apprentice’s work, and the 

plumber’s license may be revoked, suspended, or denied, under 
12

section 12-155-113, for improper work performed under his or her 

supervision. § 12-155-124(2).

¶ 20 But what does supervision of apprentices at the job site 

require for compliance with section 12-155-124? The Board 

resolved this question by requiring line-of-sight supervision over 

apprentices using soldering torches at the job site. However, in 

looking to the plain language of the statute, we see that section 

12-155-124 does not expressly provide that compliance requires 

this specific degree of supervision. See Bd. of Educ. v. Wilder, 960 

P.2d 695, 703 (Colo. 1998) (laws must provide fair notice of what 

conduct is prohibited or mandated, or risk inviting arbitrary and 

discriminatory enforcement). The plain language of the statute says

“[s]upervision requires that a licensed plumber supervise 

apprentices at the job site” and that one licensed plumber shall not 

supervise more than three apprentices at the same job site. 

§ 12-155-124(1) (emphasis added). 

¶ 21 Despite legislating the supervision of apprentices — violation 

of which may result, as it did here, in a five-year license suspension 

and a $2300 fine — the Plumbing Practice Act does not define 

“supervision,” “supervise,” or “job site” anywhere in its text. And 
13

the Board has not provided any written guidance in the form of 

rules or position statements to assist individuals in the plumbing 

trade in ensuring compliance with the statute.

¶ 22 Because the terms in question are not defined by statute, we 

first look to their dictionary meanings. Cowen v. People, 2018 CO 

96, ¶ 14. The terms “job site” and “supervise” or “supervision” are 

defined broadly by both common and technical dictionaries.

¶ 23 The common dictionary definition of “supervise” is “to be in 

charge of.” Merriam-Webster Dictionary, https://perma.cc/X8D2-

3XEC. The term “job site” does not have its own common dictionary 

definition, but in the context of this case, we can combine the 

definitions of “job” and “site” to ascertain the common meaning of 

the full term. The word “job” means “the object or material on 

which work is being done,” Merriam-Webster Dictionary, 

https://perma.cc/F9XY-XWM9, and “site” means “the spatial 

location of an actual or planned structure or set of structures (such 

as a building, town, or monuments),” or, alternatively, “the place, 

scene, or point of an occurrence or event,” Merriam-Webster 

Dictionary, https://perma.cc/3JNM-67MA. In combining these 

definitions within the context of plumbing, “supervise apprentices 
14

at the job site” means for a licensed plumber to be in charge of

apprentices at the spatial location of an actual or planned structure 

or set of structures on which, or the place or scene where, plumbing 

work is being done.

¶ 24 As defined by a technical construction dictionary, 

“supervision” means “[d]irection of work performed by the 

contractor’s (or others) workers on site, as specifically defined by 

the contract.” RSMeans Illustrated Construction Dictionary 307 

(student ed. 2012). And “job site” means “[t]he area within the 

defined boundaries of a project.” Id. at 170. Combining these 

technical definitions, we see that “supervise apprentices at the job 

site” means for a supervising plumber to direct the work performed 

by apprentices in the area within the defined boundaries of a 

project, as specifically defined by the applicable contract.

¶ 25 In reviewing these definitions, we conclude that their common 

meanings are insufficient to resolve the questions at issue —

namely, what is practically required of a licensed plumber to 

supervise or “be in charge of” an apprentice, and what is the 

physical proximity required of the licensed plumber in relation to 

the apprentice’s location?
15

¶ 26 The commonly accepted definitions leave the challenged terms 

susceptible to more than one reasonable interpretation, as is 

illustrated by the testimony elicited during the ALJ hearing. At the 

hearing, several witnesses testified as to their understanding of 

what is required to “supervise apprentices at the job site” based on 

their plumbing experience. Their testimony establishes consensus 

that a single “job site” is generally associated with a single 

construction permit number. But ambiguity remains: What does 

supervision “at the job site” contemplate when multiple buildings in 

a planned residential community are encompassed within a single 

permit? 

¶ 27 Based on the witnesses’ hearing testimony, we can discern at 

least three possible interpretations of “supervise apprentices at the 

job site”:

(1) A licensed plumber must be in the same building as and 

have direct line-of-sight of an apprentice at all times 

when the apprentice is performing plumbing work.

(2) As a general rule, a licensed plumber should accompany 

an apprentice in the same building, but that is not 

always required, especially if an emergency arises for 
16

which the licensed plumber must leave. Apprentices 

should only be permitted to use soldering torches with 

direct line-of-sight supervision.

(3) A licensed plumber need not be in the same building as 

the apprentice but must be in one of the buildings under 

construction on the permit and must inspect and sign off 

on the apprentice’s work.

¶ 28 Based on this testimony, the ALJ derived her own 

interpretation of section 12-155-124: a licensed plumber must 

remain in the same building in which an apprentice is working and 

is required to maintain line-of-sight supervision over apprentices 

using soldering torches.

¶ 29 Because the intended scope of section 12-155-124 is unclear 

and, as the testimony reveals, capable of more than one reasonable 

construction, we conclude that section 12-155-124 is ambiguous. 

Holcomb, 172 P.3d at 890; Zapotocky, 869 P.2d at 1238. We must 

therefore turn to other tools of statutory interpretation to guide our 

analysis.
17

2. Common Law and Laws on Similar Subjects

¶ 30 Section 12-155-124 has not previously undergone judicial 

scrutiny. In doing so now, we first look to the construction of laws 

on similar subjects for assistance. Town of Erie v. Eason, 18 P.3d 

1271, 1276 (Colo. 2001). Like the Plumbing Practice Act, 

Colorado’s statutes governing the practice of electricians are also 

found in Title 12, Business Professions and Occupations. See 

§§ 12-115-101 to -124, C.R.S. 2019. And also like the Plumbing 

Practice Act, the statutes regulating electricians contain a provision 

for the supervision of apprentices by licensees, see § 12-115-115, 

C.R.S. 2019, and a provision for disciplinary action against a 

licensee for failure to supervise apprentices properly, see 

§ 12-115-122, C.R.S. 2019.

¶ 31 Notably, however, the electrician statutes were substantively 

modified in 2019 to “define[] the difference between supervision and 

direct supervision as it applies to apprentices.” Legislative Council 

of the Colo. Gen. Assembly, Fiscal Note on S.B. 19-156, at 2 (Mar. 

7, 2019), https://perma.cc/K6UY-EDDY; see Ch. 136, sec. 14, 

§ 12-115-115, 2019 Colo. Sess. Laws 3204; Ch. 136, sec. 17, 

§ 12-115-122, 2019 Colo. Sess. Laws 3207-08. 
18

¶ 32 The relevant statutory versions in effect prior to the 

amendments stated:

(1) Any person may work as an apprentice but 

shall not do any electrical wiring for the 

installation of electrical apparatus or 

equipment for light, heat, or power except 

under the supervision of a licensed electrician. 

The degree of supervision required shall be no 

more than one licensed electrician to supervise

no more than three apprentices at the jobsite.

(2) Any electrical contractor, journeyman 

electrician, master electrician, or residential 

wireman who is the employer or supervisor of 

any electrical apprentice working at the trade 

shall be responsible for the work performed by 

such apprentice. . . .

(3)(b) Such apprentice shall be under the 

supervision of either a licensed electrician or a 

residential wireman as set forth in subsection 

(1) of this section.

§ 12-23-110.5, C.R.S. 2018 (emphasis added). And a licensed 

electrician could be disciplined by the State Electrical Board for 

failure to “adequately supervise an apprentice who is working at the 

trade pursuant to section 12-23-110.5.” § 12-23-118(1)(j), C.R.S. 

2018 (emphasis added).

¶ 33 Following the Department of Regulatory Agencies’ sunset 

review of the article governing the practice of electricians, the 
19

legislature modified the statutes to specifically qualify all 

occurrences of electrician apprentice “supervision” as “direct”:

(1) Any person may work as an apprentice but 

shall not do any electrical wiring for the 

installation of electrical apparatus or 

equipment for light, heat, or power except 

under the direct supervision of a licensed 

electrician. A licensed electrician shall not 

directly supervise more than three apprentices 

at a job site.

(2) An electrical contractor, journeyman 

electrician, master electrician, or residential 

wireman who is the employer or direct 

supervisor of any electrical apprentice working 

at the trade is responsible for the work 

performed by the apprentice. . . .

(3)(b) An apprentice must be under the direct 

supervision of a licensed electrician as set forth 

in subsection (1) of this section.

§ 12-115-115 (emphasis added). And a licensed electrician can now 

be disciplined by the State Electrical Board for failure to 

“adequately directly supervise an apprentice who is working at the 

trade pursuant to section 12-115-115.” § 12-115-122(1)(j)

(emphasis added).

¶ 34 Furthermore, the legislature added definitions for “direct 

supervision” and “supervision” to the electrician statutory scheme: 
20

“Direct supervision” means that the 

supervising licensed master electrician, 

journeyman electrician, or residential wireman 

is physically present at the same physical 

address where the apprentice is working.

. . . .

“Supervision” means the management of a 

project to ensure that work on the project is 

done correctly and according to the law.

§ 12-115-103(2.5), (12), C.R.S. 2019. 

¶ 35 We find these amendments to the electrician statutes 

informative, in that the legislature chose to apply this narrower 

definition of supervision only to electrician apprentices, not to 

plumbing apprentices. If the legislature intended that the 

references to supervision of electrician apprentices referred to direct

“management of a project to ensure that work on the project is done 

correctly and according to the law,” there would have been no need 

for it to qualify the term. 

¶ 36 The legislature could have made similar modifications to the 

analogous sections of the Plumbing Practice Act, but it did not. Cf. 

Mook v. Bd. of Cty. Comm’rs, 2020 CO 12, ¶¶ 34-35 (observing that 

the term “contiguous” as more narrowly defined in other unrelated 

statutes does not contain similar qualification language in the 
21

statute at issue, thereby informing the court’s statutory 

interpretation analysis). “Just as important as what the statute

says is what the statute does not say. . . . We should not construe 

these omissions by the General Assembly as unintentional.” 

Auman v. People, 109 P.3d 647, 656-57 (Colo. 2005). We therefore 

interpret the legislature’s omission of such qualifying language 

regarding the supervision of apprentices from the Plumbing Practice 

Act as intentional. Id. at 657.

¶ 37 Though nonbinding, we also find support in case law from 

other jurisdictions involving the supervision of subordinates and 

construction at job sites. In a case that required the court to 

determine insurance liability for weather delays in a construction 

project, the United States District Court for the Eastern District of 

Louisiana relied on a dictionary of architecture and construction to 

find that “the term job site means, quite simply, the site of a 

construction project. The term ‘site’ is also defined as ‘the specific 

location of a building or buildings.’” J. Ray McDermott & Co. v. Fid. 

& Cas. Co., 466 F. Supp. 353, 364 (E.D. La. 1979) (emphasis added)

(citations omitted). 
22

¶ 38 And our own supreme court, albeit in dicta, provides 

additional guidance. In a case decided in 1926, the court affirmed 

judgment entered against several plumbing apprentices for 

engaging in plumbing work without a license in violation of a city 

ordinance. Evans v. City & Cty. of Denver, 79 Colo. 533, 247 P. 173 

(1926). The court concluded that the apprentices’ employer had 

“allowed [them] to work alone and without supervision to such an 

extent that the apprentices were really working as journeymen 

plumbers.” Id. at 536, 247 P. at 174. But in so concluding, the 

court declared in dicta that 

[e]ven under the strictest view of it an 

apprentice need not perform every stroke of his 

labor as a learner under the constant eye of the 

master, so long as the superior skill of the 

master appears in the work through his 

directions and instructions given to the 

apprentice.

Id. (quoting City of St. Louis v. Bender, 154 S.W. 88, 92 (Mo. 1913)

(Lamm, J., concurring)) (emphasis added).

¶ 39 We find this dictum instructive in at least discounting the 

requirement for line-of-sight supervision of apprentices engaged in 

plumbing work. The Evans court stated that supervision of 

apprentice plumbers under a 1926 city ordinance did not require 
23

“the constant eye of the master,” provided that the supervising 

plumber’s directions and instructions appear in the final product. 

Id. (quoting Bender, 154 S.W. at 92) (Lamm, J., concurring).

¶ 40 Finally, several cases involving violation of the federal 

Occupational Safety and Health Act (OSHA) indicate that direct, 

line-of-sight supervision of trade apprentices is not required. See 

Capital Elec. Line Builders of Kan., Inc. v. Marshall, 678 F.2d 128, 

131 (10th Cir. 1982) (concluding that the supervising licensed 

electrician was not required to actually accompany apprentices in 

the aerial bucket or oversee their work from below because “such a 

requirement would be unreasonable”); Horne Plumbing & Heating 

Co. v. Occupational Safety & Health Review Comm’n, 528 F.2d 564, 

569-70 (5th Cir. 1976) (finding that there was nothing more that 

the supervisor could have done to prevent the OSHA violation “other 

than personally directing the operation himself,” which the court 

determined “would be a wholly unnecessary, unreasonable, and 

infeasible requirement” because, although “the courts have 

emphasized the importance of adequate instruction and supervision 

in safety matters, they have consistently refused to require 

measures beyond those which are reasonable and feasible”); Cape & 
24

Vineyard Div. of New Bedford Gas v. Occupational Safety & Health 

Review Comm’n, 512 F.2d 1148, 1155 (1st Cir. 1975) (“There is 

nothing in the record indicating that prudence would require a 

supervisor or buddy constantly to watch the employee on the pole, 

or that any such practice would be feasible.”).

¶ 41 With this framework in mind, we enlist further guidance from 

other principles of statutory construction.

3. Legislative Declaration and Purpose of the Statute

¶ 42 The Plumbing Practice Act’s legislative declaration proclaims

that the purpose of the Act is to safeguard public health. See 

§ 12-58-101(2), C.R.S. 2018. And ensuring that plumbing 

apprentices are appropriately supervised certainly falls within the 

purview of this purpose.

(1) The general assembly hereby finds that:

(a) Improper plumbing can adversely 

affect the health of the public and that 

faulty plumbing is potentially lethal and 

can cause widespread disease and an 

epidemic of disastrous consequences;

(b) To protect the health of the public, it 

is essential that plumbing be installed by 

persons who have proven their knowledge 

of the sciences of pneumatics and 
25

hydraulics and their skill in installing 

plumbing.

(2) Consistent with its duty to safeguard the 

health of the people of this state, the general 

assembly hereby declares that individuals who 

plan, install, alter, extend, repair, and 

maintain plumbing systems should be 

individuals of proven skill.

§ 12-58-101, C.R.S. 2018.

¶ 43 Similarly, the Board’s program director testified at the ALJ 

hearing that the public policy behind apprentice supervision is “to 

ensure the correct and safe installation of the plumbing.”

¶ 44 Recalling from above the multiple interpretations offered by 

witnesses during the ALJ hearing of what it means to supervise 

apprentices at the job site, it is apparent that the public safety 

objective can be achieved under each of the perceived 

constructions. Whether a licensed plumber maintains line-of-sight 

supervision of an apprentice during soldering only, accompanies an 

apprentice at all times, or is nearby but returns to inspect and sign 

off on the apprentice’s work, the public policy of ensuring correct 

and safe installation of plumbing can be achieved. 

¶ 45 Yet, clear construction of section 12-155-124 remains elusive 

because it does not sufficiently prescribe the level or type of 
26

supervision required. So, taking these safety objectives into 

account, we turn finally to the Board’s interpretation of section 

12-155-124 and consider its consequences.

4. Consequences of the Board’s Interpretation

¶ 46 In her initial decision, the ALJ concluded that section 

12-155-124 requires licensed plumbers to maintain line-of-sight 

supervision when apprentices use soldering torches and that job 

site refers to the same building in which the apprentice is working. 

In its final order, the Board adopted the ALJ’s ultimate conclusions, 

agreeing that section 12-155-124 requires line-of-sight supervision 

of apprentices using soldering torches, but did not specifically 

define job site, reasoning that line-of-sight supervision necessarily 

requires that the supervising plumber and apprentice be in the 

same building.

¶ 47 As an initial matter, we recall that principles of statutory 

construction prohibit the Board from altering statutory language by 

adding or subtracting words. See Holcomb, 172 P.3d at 894. And

terms even slightly similar to line-of-sight supervision or those 

alluding to a job site being a single building are nowhere to be 

found in the Plumbing Practice Act. Therefore, the Board
27

inappropriately altered the language of section 12-155-124 by 

adding words.

¶ 48 Relatedly, and as previously discussed, the legislature recently 

amended the electrician statutes to specify that apprentice 

supervision must be “direct” — with “direct supervision” requiring

that the supervising electrician “is physically present at the same 

physical address where the apprentice is working.” § 12-115-103. 

As we pointed out, the legislature declined to make similar 

amendments to the Plumbing Practice Act. We further note that,

though the legislature added language in the electrician statutes to 

delineate between “supervision” and “direct supervision,” it did not 

define “direct supervision” as requiring line of sight. In so noting, 

we are reminded of our supreme court’s declaration that “[j]ust as 

important as what the statute says is what the statute does not 

say.” Auman, 109 P.3d at 656-57. 

¶ 49 Furthermore, adopting the Board’s interpretation would lead 

to a construction that is not consistent or in harmony with other 

parts of the statute. See Nieto, 993 P.2d at 501. As discussed 

above in Part III.C.1, section 12-155-124 directs that a licensed 

plumber is not permitted to supervise more than three apprentices 
28

at the same job site. Under the Board’s construction requiring 

line-of-sight supervision, the three apprentices would not only have 

to be in the same building simultaneously but also all working in 

the supervisor’s line of sight, creating potential logistical difficulties, 

or even thwarting the benefit of allowing one supervisor to supervise 

three apprentices.4

¶ 50 Absent clear language from the legislature indicating an intent 

to define “supervise” as line-of-sight supervision, we conclude that 

the Board misconstrued the law by reading additional words into

section 12-155-124 that do not appear in the statutory language. 

See Holcomb, 172 P.3d at 894. And because we are not bound by 

an agency decision that misapplies or misconstrues the law, see 

Welby Gardens, 71 P.3d at 1000, we decline to endorse the Board’s 

construction.

 

4 We acknowledge that the newly amended electrician statutes also 

allow for supervision of up to three electrician apprentices at a job 

site and that the supervision in that context must be “direct.” See 

§ 12-115-115, C.R.S. 2019. But “direct” supervision there requires 

only that a supervising electrician be physically present at the same

physical address where the three apprentices are working. Being 

physically present does not necessarily equate with a line-of-sight 

view, which removes the logistical issue present with the Board’s 

interpretation of the plumbing statute here.
29

5. What it Means to Supervise Apprentices at the Job Site

¶ 51 None of the previously discussed tools of statutory 

construction, standing alone, provides us with a clear meaning for 

“supervise apprentices at the job site.” But by synthesizing the 

results from our application of these tools, we can arrive at a 

constitutionally valid construction of the statute.

¶ 52 We conclude that to “supervise apprentices at the job site”

means that a licensed plumber must be within a sufficient distance 

of the apprentice, whether in or outside a building, such that by 

monitoring, inspecting, and signing off on the apprentice’s work 

with reasonable frequency, the correct and safe installation of 

plumbing can be achieved. This construction is wholly consistent 

with each of the statutory canons we examined:

1. Plain meaning: under our interpretation, a licensed plumber 

will be in charge of apprentices at the spatial location of a 

structure or set of structures on which plumbing work is 

being done by the apprentices.

2. Laws on similar subjects: cognizant of the legislature’s 

amendments to define “direct supervision” in the electrician 

statutes and intentional omission of similar terms in the 
30

Plumbing Practice Act, our construction does not read into 

the statute words that were not included.

3. Common law: drawing guidance from our supreme court, an 

apprentice need not be under “the constant eye of the 

master” because the supervising licensed plumber will 

periodically evaluate the apprentice’s work to ensure that 

the directions and instructions provided to the apprentice 

appear in the final product. See Evans, 79 Colo. at 536, 

247 P. at 174 (quoting Bender, 154 S.W. at 92) (Lamm, J., 

concurring).

4. Legislative declaration and purpose of the statute: with a 

licensed plumber monitoring, inspecting, and signing off on 

an apprentice’s work with reasonable frequency, the correct 

and safe installation of plumbing can be achieved.

¶ 53 This construction of section 12-155-124 allows us to preserve 

the constitutionality of the statute, as we are required to do. See

Zapotocky, 869 P.2d at 1240.5

 

5 To be clear, we do not mean to suggest that the legislature could 

not, if it chose to, specifically provide for line-of-sight supervision, 
31

IV. Mr. Welch and Confidence Did Not Violate Section 12-155-124

¶ 54 Finally, we further conclude that, based on the ALJ’s findings 

of evidentiary fact, Mr. Welch and Confidence did not violate section 

12-155-124. 

¶ 55 We have determined that compliance with the statute requires 

that a licensed plumber supervising apprentices be within a 

sufficient distance of the apprentices, whether in or outside a 

building, such that by monitoring, inspecting, and signing off on 

the apprentice’s work with reasonable frequency, the correct and 

safe installation of plumbing can be achieved. In the initial order, 

the ALJ found that the supervising journeyman plumber was 

working near the house in which the apprentice was working when 

the apprentice was using the soldering torch. Moreover, the ALJ

 

or define “job site” as a single building or even a more specific locus 

of work. We only hold that, in the absence of such clear language, 

the statute as interpreted by the ALJ and adopted by the Board may 

provide constitutionally deficient notice of what the statute 

requires. See Rein v. Meagher, 2020 CO 56, ¶ 33 (“The essential 

inquiry in addressing a void for vagueness challenge is whether the 

statute ‘forbids or requires the doing of an act in terms so vague 

that persons of ordinary intelligence must necessarily guess as to 

its meaning and differ as to its application.’” (quoting People v. 

Gross, 930 P.2d 933, 937 (Colo. 1992))). 
32

accepted and adopted as part of her findings Mr. Welch’s testimony

that (1) all of the houses in the entire master-planned community 

were the “job site,” with journeymen at the site working in multiple 

houses; and (2) the supervising journeymen were expected to 

inspect and sign off on the work done on the premises that day or 

face disciplinary measures. Accordingly, we conclude that Mr. 

Welch and Confidence complied with the requirements of section 

12-155-124 as set forth in this opinion. 

¶ 56 Because we conclude that section 12-155-124 is constitutional 

but that the Board erred in its interpretation of the statute, we do 

not reach Mr. Welch and Confidence’s additional contention that 

the Board also erred by finding that the ALJ properly relied on the 

former Confidence employee’s hearing testimony for her 

interpretation.

V. Conclusion

¶ 57 The Board’s order is vacated.

JUDGE ROMÁN and JUDGE TOW concur.