(a) What is the purpose of this section? This section limits the amount of sulfur contained in fuels that are burned at stationary sources within the Indian reservation to control emissions of sulfur dioxide (SO2) to the atmosphere and ground-level concentrations of SO2.

(b) Who is affected by this section? This section applies to any person who sells, distributes, uses, or makes available for use, any fuel oil, coal, solid fuel, liquid fuel, or gaseous fuel within the Indian reservation.

(c) What is exempted from this section? This section does not apply to gasoline and diesel fuel, such as automotive and marine diesel, regulated under 40 CFR part 80.

(d) What are the sulfur limits for fuels? A person must not sell, distribute, use, or make available for use any fuel oil, coal, solid fuel, liquid fuel, or gaseous fuel that contains more than the following amounts of sulfur:

(1) For distillate fuel oil, 0.3 percent by weight for ASTM Grade 1 fuel oil;

(2) For distillate fuel oil, 0.5 percent by weight for ASTM Grade 2 fuel oil;

(3) For residual fuel oil, 1.75 percent sulfur by weight for ASTM Grades 4, 5, or 6 fuel oil;

(4) For used oil, 2.0 percent sulfur by weight;

(5) For any liquid fuel not listed in paragraphs (d)(1) through (d)(4) of this section, 2.0 percent sulfur by weight;

(6) For coal, 1.0 percent sulfur by weight;

(7) For solid fuels, 2.0 percent sulfur by weight;

(8) For gaseous fuels, 1.1 grams of sulfur per dry standard cubic meter of gaseous fuel (400 parts per million at standard conditions).

(e) What are the reference methods for determining compliance? The reference methods for determining the amount of sulfur in a fuel are as follows:

(1) Sulfur content in fuel oil or liquid fuels: ASTM methods D2880-03, D4294-03, and D6021-96 (Reapproved 2001)€1 (incorporated by reference, see § 49.123(e));

(2) Sulfur content in coal: ASTM methods D3177-02, D4239-04a, and D2492-02 (incorporated by reference, see § 49.123(e));

(3) Sulfur content in solid fuels: ASTM method E775-87€1 (Reapproved 2004) (incorporated by reference, see § 49.123(e));

(4) Sulfur content in gaseous fuels: ASTM methods D1072-90(Reapproved 1999), D3246-96, D4084-94€1 (Reapproved 1999), D5504-01, D4468-85€1 (Reapproved 2000), D2622-03, and D6228-98€1 (Reapproved 2003) (incorporated by reference, see § 49.123(e)).

(f) Are there additional requirements that must be met? (1) A person subject to this section must:

(i) For fuel oils and liquid fuels, obtain, record, and keep records of the percent sulfur by weight from the vendor for each purchase of fuel. If the vendor is unable to provide this information, then obtain a representative grab sample for each purchase and test the sample using the reference method.

(ii) For gaseous fuels, either obtain, record, and keep records of the sulfur content from the vendor, or continuously monitor the sulfur content of the fuel gas line using a method that meets the requirements of Performance Specification 5, 7, 9, or 15 (as applicable for the sulfur compounds in the gaseous fuel) of appendix B and appendix F of 40 CFR part 60. If only purchased natural gas is used, then keep records showing that the gaseous fuel meets the definition of natural gas in 40 CFR 72.2.

(iii) For coal and solid fuels, either obtain, record, and keep records of the percent sulfur by weight from the vendor for each purchase of coal or solid fuel, or obtain a representative grab sample for each day of operation and test the sample using the reference method. If only wood is used, then keep records showing that only wood was used. The owner or operator of a coal- or solid fuel-fired source may apply to the Regional Administrator for a waiver of thisprovision or for approval of an alternative fuel sampling program.

(2) Records of fuel purchases and fuel sulfur content must be kept for a period of five years from date of purchase and must be made available to the Regional Administrator upon request.

(3) The owner or occupant of a single-family residence, and the owner or manager of a residential building with four or fewer dwelling units, is not subject to the requirement to obtain and record the percent sulfur content from the vendor if the fuel used in an oil, coal, or gas furnace is purchased from a licensed fuel distributor.

(g) Definitions of terms used in this section. The following terms that are used in this section are defined in § 49.123 General provisions: Act, air pollutant, ambient air, coal, distillate fuel oil, emission, fuel, fuel oil, gaseous fuel, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, owner or operator, reference method, refuse, Regional Administrator, residual fuel oil, solid fuel, source, standard conditions, stationary source, used oil, and wood.