Drinking water secondary standards and lead free plumbing practice questions
20 free practice questions from 40 CFR Part 143. Each answer is explained and linked to the rule it comes from.
Drinking water secondary standards and lead free plumbing
20 questions across 8 topics. After each answer you see why it is right, with a link to the official source.
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Purpose and status of secondary standards
1. According to 143.1, what may exist at considerably higher concentrations of the contaminants the secondary regulations control?
- A. Federal enforcement duties for every public water system
- B. Health implications as well as aesthetic degradation
- C. Automatic MCL violations under Part 141
- D. A duty to stop serving water
Show answer
Answer: B. Health implications as well as aesthetic degradation
143.1: "At considerably higher concentrations of these contaminants, health implications may also exist as well as aesthetic degradation."
2. Under 143.2(f), SMCLs are levels that, in the judgement of the Administrator, are requisite to protect what?
- A. The public welfare
- B. Treatment plant equipment
- C. Source water ecosystems
- D. The structural life of distribution mains
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Answer: A. The public welfare
143.2(f): "Secondary maximum contaminant levels means SMCLs which apply to public water systems and which, in the judgement of the Administrator, are requisite to protect the public welfare."
3. Under the 143.2(f) definition, the SMCL is the maximum permissible level of a contaminant in water delivered where?
- A. At the raw water intake of the source
- B. At the entry point to the distribution system
- C. To the free flowing outlet of the ultimate user of public water system
- D. At the treatment plant's finished water reservoir
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Answer: C. To the free flowing outlet of the ultimate user of public water system
143.2(f): the SMCL means "the maximum permissible level of a contaminant in water which is delivered to the free flowing outlet of the ultimate user of public water system."
4. 143.2(f) excludes contaminants added to the water under circumstances controlled by the user. Which contaminants does it keep in the definition anyway?
- A. Those added by a home water softener
- B. Those added by a point-of-use filter the user installed
- C. Those added by a chemical feeder the user installed at the tap
- D. Those resulting from corrosion of piping and plumbing caused by water quality
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Answer: D. Those resulting from corrosion of piping and plumbing caused by water quality
Contaminants added under circumstances controlled by the user are excluded, "except those resulting from corrosion of piping and plumbing caused by water quality."
Secondary maximum contaminant levels
5. What does 143.3 say States may do with the secondary levels listed in its table?
- A. Establish higher or lower levels appropriate to local conditions, provided public health and welfare are not adversely affected
- B. Only adopt the listed levels exactly as written
- C. Only establish lower levels, never higher ones
- D. Establish higher levels only for systems serving fewer than 25 people
Show answer
Answer: A. Establish higher or lower levels appropriate to local conditions, provided public health and welfare are not adversely affected
The levels "represent reasonable goals for drinking water quality. The States may establish higher or lower levels" dependent upon local conditions, "provided that public health and welfare are not adversely affected."
Source: eCFR: 40 CFR 143.3, Secondary maximum contaminant levels (as of Nov 4, 2026)
6. Which entry in the 143.3 table has the level "Non-corrosive" instead of a number?
- A. pH
- B. Copper
- C. Total dissolved solids
- D. Corrosivity
Show answer
Answer: D. Corrosivity
The 143.3 table lists "Corrosivity Non-corrosive." pH has a numeric range, and copper and TDS are in mg/l.
Source: eCFR: 40 CFR 143.3, Secondary maximum contaminant levels (as of Nov 4, 2026)
7. Which contaminant does the 143.3 table give a secondary level stated as a range, 0.05 to 0.2 mg/l?
- A. Manganese
- B. Iron
- C. Aluminum
- D. Foaming agents
Show answer
Answer: C. Aluminum
The 143.3 table lists "Aluminum" at "0.05 to 0.2 mg/l." Manganese is 0.05 mg/l, iron 0.3 mg/l and foaming agents 0.5 mg/l.
Source: eCFR: 40 CFR 143.3, Secondary maximum contaminant levels (as of Nov 4, 2026)
Monitoring for secondary contaminants
8. 143.4(a) recommends a minimum interval for monitoring the secondary parameters. What monitoring does it use as the benchmark for that interval?
- A. The lead and copper tap sampling schedule in subpart I of Part 141
- B. The monitoring performed for inorganic chemical contaminants listed in the National Interim Primary Drinking Water Regulations as applicable to community water systems
- C. The routine total coliform monitoring schedule in subpart Y of Part 141
- D. The disinfectant residual monitoring schedule in subpart L of Part 141
Show answer
Answer: B. The monitoring performed for inorganic chemical contaminants listed in the National Interim Primary Drinking Water Regulations as applicable to community water systems
143.4(a): "It is recommended that the parameters in these regulations should be monitored at intervals no less frequent than the monitoring performed for inorganic chemical contaminants listed in the National Interim Primary Drinking Water Regulations as applicable to community water systems." It adds that more frequent monitoring may be appropriate "as directed by the State."
9. Under 143.4(b), measurement of pH, copper and fluoride to determine compliance under 143.3 may be conducted with one of the methods in which section?
- A. 141.74(a)
- B. 141.89(a)
- C. 141.131(b)
- D. 141.23(k)(1)
Show answer
Answer: D. 141.23(k)(1)
143.4(b): "Measurement of pH, copper and fluoride to determine compliance under § 143.3 may be conducted with one of the methods in § 141.23(k)(1)."
Product certification and compliance
10. Under 143.19(c)(2), which manufacturers or importers may elect to self-certify a custom fabricated product?
- A. Any manufacturer or importer, regardless of the number of persons employed by the manufacturer
- B. Only manufacturers having fewer than 10 employees
- C. Only manufacturers already certified by an ANSI accredited body
- D. Only importers, never domestic manufacturers
Show answer
Answer: A. Any manufacturer or importer, regardless of the number of persons employed by the manufacturer
143.19(c)(2): manufacturers or importers "may elect to self-certify any custom fabricated product" in lieu of third party certification, "regardless of the number of persons employed by the manufacturer."
Source: eCFR: 40 CFR 143.19, Required certification of products (as of Nov 4, 2026)
11. What period does 143.19(a) set for manufacturers or importers to maintain documentation substantiating a product's certification?
- A. 1 year after the product is discontinued
- B. 3 years from the date of certification
- C. At least 5 years from the date of the last sale of the product by the manufacturer or importer
- D. 2 years from the date of first sale
Show answer
Answer: C. At least 5 years from the date of the last sale of the product by the manufacturer or importer
They "must maintain documentation to substantiate the certification for at least 5 years from the date of the last sale of the product by the manufacturer or importer."
Source: eCFR: 40 CFR 143.19, Required certification of products (as of Nov 4, 2026)
12. Which product does 143.19(a)(3) say does not need to be certified?
- A. Kitchen faucets
- B. Dishwashers
- C. Drinking water fountains
- D. Refrigerator ice and water dispensers
Show answer
Answer: B. Dishwashers
143.19(a)(3) states: "Dishwashers do not need to be certified."
Source: eCFR: 40 CFR 143.19, Required certification of products (as of Nov 4, 2026)
Lead free scope and definitions
13. Besides people who introduce products into commerce, to whom does 143.10(a) say Subpart B also applies?
- A. Only State plumbing inspectors
- B. Any person who uses these products in the installation or repair of a public water system or a residential or nonresidential facility providing water for human consumption
- C. Only licensed plumbers working on community water systems
- D. Only owners of buildings built after September 1, 2020
Show answer
Answer: B. Any person who uses these products in the installation or repair of a public water system or a residential or nonresidential facility providing water for human consumption
143.10(a): "It also applies to any person who uses these products in the installation or repair of" a public water system or "A residential or nonresidential facility providing water for human consumption."
Source: eCFR: 40 CFR 143.10, Applicability and scope (as of Nov 4, 2026)
What lead free means
14. A coating is applied to the internal surfaces of a fitting component. Under 143.12(c), what lead content must be used to calculate the lead content of that component?
- A. The lead content of the coating only
- B. The lead content of the alloy only
- C. The average of the coating and the alloy
- D. The maximum lead content of both the coating and the alloy
Show answer
Answer: D. The maximum lead content of both the coating and the alloy
143.12(c): if a coating "is applied to the internal surfaces of a pipe, fitting or fixture component, the maximum lead content of both the coating and the alloy must be used to calculate the lead content of the component."
Source: eCFR: 40 CFR 143.12, Definition of lead free and calculation methodology (as of Nov 4, 2026)
15. When the lead content of a material is provided as a range, which value does 143.12(b) say must be used in the weighted average calculation?
- A. The maximum content of the range
- B. The minimum content of the range
- C. The midpoint of the range
- D. The average of the manufacturer's test results
Show answer
Answer: A. The maximum content of the range
143.12(b): "For lead content of materials that are provided as a range, the maximum content of the range must be used."
Source: eCFR: 40 CFR 143.12, Definition of lead free and calculation methodology (as of Nov 4, 2026)
16. A fixture contains a filter with activated carbon. How does 143.12(e) treat the filter media when calculating the product's weighted average lead content?
- A. The media count double toward the total wetted surface area
- B. The media must be tested separately against the 0.2 percent limit
- C. The media are not to be used in determining the total wetted surface area of the entire product
- D. The media replace the housing in the calculation
Show answer
Answer: C. The media are not to be used in determining the total wetted surface area of the entire product
143.12(e): media contained in filters "are not to be used in determining the “total wetted surface area of the entire product”" in paragraph (b).
Source: eCFR: 40 CFR 143.12, Definition of lead free and calculation methodology (as of Nov 4, 2026)
Use, sale and labeling prohibitions
17. What does 143.13(b) exclude from the use prohibition in 143.13(a)?
- A. Solder used for emergency repairs of copper service lines
- B. Brass valves installed before 2020
- C. Water meters owned by the public water system
- D. Leaded joints necessary for the repair of cast iron pipes
Show answer
Answer: D. Leaded joints necessary for the repair of cast iron pipes
143.13(b): "Paragraph (a) of this section shall not apply to leaded joints necessary for the repair of cast iron pipes."
Source: eCFR: 40 CFR 143.13, Use prohibitions (as of Nov 4, 2026)
18. Under 143.14, enforcing the use prohibitions is a condition of what for States?
- A. Receiving a full allotment of Public Water System Supervision grants under section 1443(a)
- B. Keeping primary enforcement responsibility for the Revised Total Coliform Rule
- C. Receiving Drinking Water State Revolving Fund loans for lead service line replacement
- D. Approval of the State's operator certification program
Show answer
Answer: A. Receiving a full allotment of Public Water System Supervision grants under section 1443(a)
"As a condition of receiving a full allotment of Public Water System Supervision grants under section 1443(a) of the Safe Drinking Water Act, States must enforce" the requirements, through State or local plumbing codes or other means.
Source: eCFR: 40 CFR 143.14, State enforcement of use prohibitions (as of Nov 4, 2026)
19. Under 143.15(b), which persons engaged in the business of selling plumbing supplies are excepted from the ban on selling solder or flux that is not lead free?
- A. Retailers
- B. Wholesalers
- C. Manufacturers
- D. Importers
Show answer
Answer: C. Manufacturers
143.15(b): "No person engaged in the business of selling plumbing supplies in the United States, except manufacturers, may sell solder or flux that is not lead free." Such solder or flux must still carry the 143.18 label.
Source: eCFR: 40 CFR 143.15, Introduction into commerce prohibitions (as of Nov 4, 2026)
Exemptions
20. What size condition does 143.16(b) set for water distribution main gate valves to be exempt?
- A. Smaller than 2 inches in diameter
- B. 2 inches in diameter or larger
- C. 1 inch in diameter or larger
- D. 6 inches in diameter or larger
Show answer
Answer: B. 2 inches in diameter or larger
143.16(b) exempts "water distribution main gate valves (provided that such valves are 2 inches in diameter or larger)."