REV09300 - Laserfiche WebLink

Home Browse Search

%~~ . • • / Colorado, in this informal submittal, has proposed co add additional language a[ kale 4.04.} that rill make the variance alternative design for general fill regnireme__^.ts at Rule 4.04.: also applicable to the specific head-of-hollov fill regulatiot_ found at kale 4.09.3. Colorado indicated in the Statement o: and Purpose section of this informal amendment that tae var:a^~ Rule 9.D9.1(3) already applies to head-of-hollov fills, and tn. proposed lanquaae at Rule 4.09.3 is simply to clarify this. 5- the above discussion under H-A. To be no less effective than the Federal regulations, Colorado not apply the general fill variance found at kale 4.09.1(3) tc ' ~ head-of-hollov fill provisions at Rule 4.09.3. H-C Rule 4.09.4(1); 30 CFR 816.73/817.73 (Durable Rock Fills) Colorado submitted formally a nev Rule 4.09.4 in CO-384. See OSMAE issue letter dated February 7, 1989 for disposition of :. E-C and &-4. (Note: In Eaclosure A of the February 7, 1989 :_ le*_ter 052SRE failed to acimovledge that E-C vas also partially addressed in CO-3B9.) Colorado, in this informal submittal, has proposed additional lanouaae at Ruie 4.09.4(1) that will make the variance for alternative design specifications found in the general fill requirements at kale 4.D9.1(3) also applicable to the durable • fill regulations proposed at 4.09.4. As discussed in the finding for "excess spoil - valley fills," number E-A, there are several scenarios that could render this to be less effective than tae Federal regulation. Incorporat_- the "alternative specification" into the durable roc's fills vc_ (1) alloy nondarahie material to comprise more than 20 percent the fill volume, (2) not meet the requirements of design safe=: factors of 1.5 for end of construction and 1.1 for earthanaice condition, (3) not require as internal 6rainaae system vhen pi. as a head-of-hollov fill, and (4) not require the coastructio= diversions to safely pass runoff from areas adiacent to and ac- the fill and runoff from the surface of the fill from a 100-ve- 24-hour storm event. It should be noted, Colorado's approved program alloys an alternative method to construct durable rock fills. This alternative alloys placement of material by dumping in a single lift, provided that the method is certified by a qualified registered professional engineer. To be no less effective than the Federal reaulatioas, Coioradc not apply the "alternative specification" provision of the gene provisions at Ruie S.D9.1(3) to the durable rock fill provisic~ Rule 4.04.4. 5