Unstable and unsuitable materials, such as earth containing organic material or cinders, found existing in the subgrade of the improvement, shall be excavated and removed and replaced with a suitable material satisfactory to the Engineer. The contractor shall do all ditching, pumping and bailing, build all drains and do all other work necessary to keep the excavation clear of ground water or storm water during the progress of the work and until the finished work is safe from injury.
Whenever the excavation is carried beyond the lines of grade shown on the drawings or given by the Engineer, the contractor shall, at his or her expense, refill all such excavated space with such material and in such a manner as may be directed. No frozen materials shall be used for backfilling. All backfill material shall be placed in layers not exceeding four inches in depth, and each layer shall be thoroughly packed in and compacted.
The subgrade shall be tamped or rolled until thoroughly compacted, shall be constructed true to line, grade and cross-section and shall be prepared sufficiently wide to accommodate the forms. Embankments shall be made not less than six inches wider on each side than the walk to be installed.
(Ord. 352. Passed 10-22-62.)