1. (a) The walls of a secondary containment facility must be:

   1. (1) constructed of earth, steel, concrete (precasted modules or poured), or solid masonry; and
   2. (2) designed to withstand a full hydrostatic head of any discharged liquid and weight load of material used in construction.
2. (b) Cracks and seams must be sealed to prevent leakage.
3. (c) Walls constructed of earth or other permeable materials must be lined as provided under sections 15 through 19 of this chapter.

4. (d) Earthen walls must have a horizontal-to-vertical slope consistent with good engineering practice. All interior slopes must be protected with:

   1. (1) flat road stone or a similar crushed stone material; or
   2. (2) a minimum of six (6) inches of vegetative soils planted and maintained with shallow rooted grasses.
5. (e) The top of earthen walls must be no less than two and one-half
6. (2.5) feet wide.

7. (f) Walls may not exceed six (6) feet in height above interior grade unless provisions are made for:

   1. (1) normal access and necessary emergency access to storage containers, valves, and other equipment; and
   2. (2) safe exit from secondary containment.

8. (g) Walls constructed of concrete or solid masonry must rest upon:

   1. (1) a floating base of concrete prepared to conform with section 16 of this chapter; or

   2. (2) suitable concrete footings that extend below the average frost depth.

      Joints between walls and base must be made watertight.

As added by P.L.98-2026, SEC.50.