# Standards of quality of service. **Citation:** 199 IAC 19.7 **Type / status:** regulation / current **Agency:** Iowa Utilities Commission **Effective:** 2025-07-16 **Published:** 2026-08-19 19.7(1) Purity. All gas supplied to customers shall be substantially free of impurities that may cause corrosion of mains or piping or from corrosive or harmful fumes when burned in a properly designed and adjusted burner. 19.7(2) Pressure limits. The maximum allowable operating pressure for a low-p ## Document text 19.7(1) Purity. All gas supplied to customers shall be substantially free of impurities that may cause corrosion of mains or piping or from corrosive or harmful fumes when burned in a properly designed and adjusted burner. 19.7(2) Pressure limits. The maximum allowable operating pressure for a low-pressure distribution system shall not be so high as to cause the unsafe operation of any connected and properly adjusted low-pressure gas-burning equipment. 19.7(3) Adequacy for pressure. Each utility shall have a substantially accurate knowledge of the pressures inside its piping. Periodic pressure measurements shall be taken during periods of high demand at remote locations in distribution systems to determine the adequacy of service. Records of such measurements including the date, time, and location of the measurement shall be maintained not less than two years. 19.7(4) Standards for pressure measurements. a. Secondary standards. Each utility shall own or have access to a dead weight tester that is maintained in an accurate condition. b. Working standards. Each utility must have or have access to water manometers, laboratory quality indicating pressure gauges, and field-type dead weight pressure gauges as necessary for the proper testing of the indicating and recording pressure gauges used in determining the pressure on the utility's system. Working standards must be checked periodically by comparison with a secondary standard. 19.7(5) Handling of standards. Extreme care must be exercised in the handling of standards to ensure that their accuracy is not disturbed. Each standard shall be accompanied at all times by a certificate or calibration card, duly signed and dated, on which are recorded the corrections required to compensate for errors found at the customary test points at the time of the last previous test. 19.7(6) Heating value. a. Awareness. Each utility shall have a substantially accurate knowledge of the heating value of the gas being delivered to customers at all times. b. Natural and LP gas. The heating value of natural gas and undiluted, commercially pure LP gas is not considered to be under the control of the utility. Utilities will determine the allowable range of monthly average heating values within which its customers' appliances may be expected to function properly without repeated readjustment of the burners. If the monthly average heating value is above or below the limits of the allowable range for three successive months, the customers' appliances must be readjusted in accordance with paragraph 19.4(18)"c." c. Renewable natural gas (RNG). The heating value of gas supplied from an RNG facility is considered within the control of the RNG supplier. The average daily heating value of mixed gas in a distribution system shall be at least 95 percent of that normally delivered by the pipeline supplier. RNG producers are responsible for ensuring the gas produced from the RNG facility is compatible to meet these heating requirements. d. Peak shaving or other mixed gas. The heating value of gas in a distribution system that includes gas from LP or LNG peak shaving facilities, or gas from a source other than a pipeline supplier, is considered within the control of the utility. The average daily heating value of mixed gas shall be at least 95 percent of that normally delivered by the pipeline supplier. All mixed gas shall have a specific gravity of less than 1.000, and heating value shall not be so high as to cause improper operation of properly adjusted customer equipment. e. Heating value determination and records. Unless acceptable heating value information is available for all periods from other sources, including the pipeline supplier, utilities will have a method by which the heating value of the gas in a distribution system can be accurately determined. The type, accuracy, operation, and location of equipment, and the accuracy of computation methods, shall be in accordance with accepted industry practices and equipment manufacturer's recommendations, subject to review by the commission. 19.7(7) Interruptions of service. a. Each utility shall make reasonable efforts to avoid interruptions of service, but when interruptions occur, service shall be reestablished within the shortest time practicable, consistent with safety. Records will be maintained for not less than two years of interruptions of service required to be reported pursuant to subrule 19.16(1). Utilities will periodically review these records to determine steps to be taken to prevent recurrence. b. Planned interruptions shall be made at a time that will not cause unreasonable inconvenience to customers. Interruptions shall be preceded by adequate notice to those who will be affected. ## Provenance - Official: Yes - Source: - Source ID: `ia-legislature-pipeline-safety` - SHA-256: `d01497bd009ac0a1d340cf9489177be379d2e00f20c942d2ed89aae530fe557e` - Retrieved: 2026-08-20T08:17:15.771Z - Exported: 2026-08-22T15:39:47.288Z - Document slug: `ia-iac-199-19-7` ### Source metadata ```json { "jurisdiction": "US-IA", "chapter": "199 IAC chapter 19", "exactScope": "This bounded corpus contains every current rule in 199 IAC chapters 10 and 19, the two chapters identified by the Iowa Utilities Commission pipeline-safety page, plus 15 selected Iowa Code sections that directly establish gas-utility applicability, inspection and rulemaking authority, enforcement, penalties, and acceptance of federal pipeline-safety aid. It does not claim all Iowa pipeline law or all of Iowa Code chapters 476 and 479.", "excludedScope": "Excluded are hazardous-liquid safety (which the IUC says remains exclusively with PHMSA), hazardous-liquid permitting in 199 IAC chapter 13 and Iowa Code chapter 479B, damage prevention and one-call law, agricultural restoration chapter 9, railroad-crossing chapter 42, general procedure and filing chapters, permits/orders/forms, privately owned propane service, and federal or private incorporated text. Former 199 IAC chapter 12 is inventoried as repealed and is not searchable.", "applicabilityCaveat": "Applicability depends on IUC jurisdiction, public-utility or pipeline-company status, intrastate versus interstate status, the gas and facility involved, customer count, rate regulation, exemptions, federal preemption, waivers, permits, tariffs, and Commission orders. Iowa inspects interstate gas operators only as PHMSA's agent; federal authorities retain enforcement. Chapter 19 is limited to rate-regulated gas utilities except where another law or order extends a duty.", "incorporationCaveat": "The rules incorporate or reference 49 CFR Parts 191, 192, 193, and 199; ASME B31.8-2022; NFPA 59-2024, NFPA 54-2024, and NFPA 501A-2021; other Iowa rules and statutes; federal forms and interpretations; and utility tariffs. The connector records citations but does not reproduce incorporated federal or private material, decide which edition controls beyond the state text, or grant rights in private standards.", "publicationCaveat": "The current IAC chapter listings dated August 5, 2026 are used to prove chapter and rule inventory; their official PDF and DOCX-formatted 'RTF' artifacts are archived independently. The official 2026 Iowa Code was published December 22, 2025. The live 2026 Code & Acts Sections Amended report is provisional; signed HF 2799 sections 23 and 24, effective July 1, 2026, are preserved as overlays to selected sections 476.1B and 476.2. Any unexpected selected-section amendment causes refresh failure.", "rights": "Iowa legal text and other government edicts are preserved with official attribution and cryptographic provenance. Public access does not grant rights in agency seals, website presentation, forms, utility filings, incorporated federal compilations, or privately authored standards; redistribution of those materials requires a separate rights review.", "references": [], "sourceHistory": "[ARC 9351C, IAB 6/11/25, effective 7/16/25]", "region": "IA" } ```