TABLE I
MINIMUM LINER DESIGN STANDARDS
Liner Material | Function | Minimum Field Thickness (Units as Specified) | Liner Density (Tests as Specified) | Remarks |
Geosynthetics | Primary or Secondary Liner | 30 mil | N/A | 1. A greater thickness may be required depending upon the recommendations of the manufacturer. HDPE liners shall be at least 60 MIL. |
Geosynthetics | Cap | 30 mil | N/A | 1. A greater thickness may be required depending upon the recommendations of the manufacturer. |
Natural & Remodeled Clay | Secondary Liner, Cap, Composite Component | 2 feet 2 feet 1 foot | [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90% * | 1. Minimum of 30% fines by weight less than 0.074 mm particle size (# 200 sieve). 2. Plasticity Index greater than or equal to 10.3. No coarse fragments greater than 3/4 inch in diameter. |
Sodium bentonite & Bentonite-like materials/soil mixtures | Secondary Liner, Cap, Composite Component | 2 feet 2 feet 1 foot | [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90%* | 1. Minimum of 8% powdered sodium bentonite or manufacturer's recommendations, whichever is greater. 2. No coarse fragments greater than 3/4 inch in diameter. 3. No organic matter. |
Geosynthetic Clay Liner (GCL) | Composite Component | N/A | N/A | 1. Minimum of 3/4 pound of powdered or granular sodium bentonite per square foot. |
* Percentage of maximum when using Standard Proctor method of design (Pa. PTM No. 106, Method B).
Cross References
This table cited in 25 Pa. Code § 288.434 (relating to secondary liner); 25 Pa. Code § 288.436 (relating to primary liner); and 25 Pa. Code § 288.439 (relating to surface mined areas).
TABLE II
MINIMUM LINER DESIGN STANDARDS
Liner Material | Function | Minimum Field Thickness (Units as Specified) | Liner Density (Tests as Specified) | Remarks |
Geosynthetics | Liner, Cap | 30 mil | N/A | 1. A greater thickness may be required depending upon the recommendations of the manufacturer. HDPE liners shall be at least 60 MIL. |
Natural & Remolded Clay | Cap, Composite Component | 2 feet 1 foot | [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90%* | 1. Minimum of 30% fines by weight less than 0.074 mm particle size (#200 sieve). 2. Plasticity Index greater than or equal to 10. 3. No coarse fragments greater than 3/4 inch in diameter. |
Sodium Bentonite and Bentonite-like materials | Cap, Composite Component | 2 feet 1 foot | [GREATER THAN EQUAL TO] 90%* [GREATER THAN EQUAL TO] 90%* | 1. Minimum of 8% powdered sodium bentonite or manufacturer's recommendations, whichever is greater. 2. No coarse fragments greater than 3/4 inch in diameter. 3. No organic matter. |
Geosynthetic Clay liner (GCL) | Composite Component | N/A | N/A | 1. Minimum of 3/4 pound of powdered or granular sodium bentonite. |
* Percentage of maximum when using Standard Proctor method of design (Pa. PTM No. 106, Method B).
25 Pa. Code 288 app A
This table cited in 25 Pa. Code § 288.234 (relating to final cover and grading); 25 Pa. Code § 288.535 (relating to liner); and 25 Pa. Code § 288.538 (relating to surface mined areas).