15A NCAC 13C .0203      SURFACE WATER MIGRATION

(a)  The potential for surface water contamination is based upon route characteristics, waste containment, and waste characteristics. The score for surface water migration is determined by multiplying the score determined for route characteristics in Paragraph (b) by the score determined for waste containment in Paragraph (c) then multiplying that result by the score determined for waste characteristics in Paragraph (d) and dividing that result by 14.82.

(b)  A score for route characteristics shall be determined by adding the values in Subparagraphs (b)(1) through (b)(4).

(1)           A value shall be assigned for facility slope and intervening terrain using the table entitled "Values for Facility Slope and Intervening Terrain," that is contained in 40 CFR 300, Appendix A, July 1, 1988, which is hereby incorporated by reference and does not include subsequent amendments and editions. This material is available for inspection at the Department of Environment, Health, and Natural Resources, Division of Solid Waste Management, Superfund Section, 401 Oberlin Road, Raleigh, North Carolina. Copies may be obtained from the Superfund Section at a cost of ten cents ($ .10) per page.

(2)           A value shall be assigned for one‑year 24‑hour rainfall using Table 8. The amount of rainfall shall be determined using Figure 1, entitled "24‑hour rainfall", in 40 CFR 300, Appendix A, July 1, 1988, which is hereby incorporated by reference and does not include subsequent amendments and editions.

Table 8

One‑Year 24‑hour

Rainfall Amount                                                                  Assigned Value

(inches) 

< 2.5                                                                                       0

> 2.5 to 3.0                                                                           1

> 3.0 to 3.5                                                                           2

> 3.5                                                                                       3

(3)           A value shall be assigned for distance to nearest surface water using Table 9. Distance to the nearest surface water shall be determined by measuring the shortest distance from the hazardous substance (not the facility or property boundary) to the nearest downhill body of surface water that is on the course that run‑off can be expected to follow.

Table 9

Distance                                                                Assigned Value

> 2 miles                                                                                0

> 1 to 2 miles                                                                        2

> 1000 feet to 1 mile                                                           4

> 200 feet to 1000 feet                                                       6

< 200 feet or contaminant in                                             8

surface water or sediment

Contaminant in surface water or                                       10

sediment at a drinking water intake

(4)           A value for physical state shall be assigned as determined in Rule .0202(b)(4) of this Section.

(c)  A score for containment shall be determined by using the table entitled "Containment Values for Surface Water Route," contained in 40 CFR 300, Appendix A, July 1, 1988, which is hereby incorporated by reference and does not include subsequent amendments and editions. If the site has more than one type of containment, the containment with the highest value shall be used.

(d)  A score for waste characteristics shall be assigned as determined in Rule .0202(d) of this Section.

History Note:        Authority G.S. 130A-310.2; 130A‑310.12;

Eff. June 1, 1989;

Amended Eff. July 1, 1993; November 1, 1989;

Pursuant to G.S. 150B-21.3A, rule is necessary without substantive public interest Eff. June 24, 2017.