TABLE 1
MINIMUM LINER DESIGN STANDARDS
MINIMUM FIELD | ||||
LINER MATERIAL | FUNCTION | THICKNESS (UNITS AS SPECIFIED) | LINER DENSITY (TESTS AS SPECIFIED) | REMARKS |
Geosynthetic | Primary orsecondaryliner | 30 mil | NA | 1. A greater thickness may be required depending upon the recommendations of the manufacturer. 2. HDPE liners shall be at least 60 mil. |
Geosynthetic | Cap | 30 mil | NA | 1. A greater thickness may be required depending upon the recommendations of the manufacturer. |
Natural & Remolded Clay | Secondary Liner, Composite component | 2 feet 2 feet | [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 10. 3. No coarse fragments greater than 3/4 inch in diameter . |
Sodium Bentonite & Bentonite-like materials | Secondary Liner, Composite component | 1 foot1 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 | Minimum of 3/4 pound of powdered or granular sodium bentonite per square foot. |
*Percentage is of maximum theoretical density when using Marshall method of design, and percentage of maximum when using Standard Proctor method of design (Pa. PTM No. 106, Method B).
25 Pa. Code § 273.256
This section cited in 25 Pa. Code § 273.161 (relating to liner system and leachate control plan); 25 Pa. Code § 273.234 (relating to final cover and grading); 25 Pa. Code § 273.251 (relating to scope and requirements); 25 Pa. Code § 273.254 (relating to secondary liner); 25 Pa. Code § 273.259 (relating to surface mined areas); 25 Pa. Code § 273.251 (relating to scope and requirements); and 25 Pa. Code § 285.123 (relating to impoundments-general).