Page 432 - Trenchless Technology Piping Installation and Inspection

382 Cha pte r Ni ne

detergent additives should not be used. Although the
bentonite-water, or commonly used polymer-water-slurry, is
not inherently a hazardous material, special disposal may be
required when drilling in an area known to contain toxic pol-
lutants. In such cases, disposal must be in accordance with
local laws and regulations. It may be necessary to dewater the
spoils, transport the solids to an appropriate disposal site,
and treat the water to meet disposal requirements.
• Proper locating and markings of bore path: Prior to the arrival of
the locators, the contractor should mark the path of the pro-
posed bore route, preferably using a white line or flags, and
some means of identification. In general, belowground facil-
ities within a minimum lateral distance of 10 ft of the pro-
posed bore path should be marked, unless a greater distance
is specified by state or other regulations. Other facilities
known to be in the vicinity, but believed to be beyond 10 ft,
or otherwise required minimum distance, should be con-
firmed by the corresponding owner. The actual paths and
depths of identified utility lines are typically not provided
during the planning process. They may subsequently be
determined by the owner of the proposed pipe line or its
representative.
• Proper project startup: Preconstruction meetings with the con-
tractor are useful, and may be particularly important for
unusual or difficult projects. These meetings are necessary
when requesting temporary disruption of electric or gas ser-
vice, to reduce the likelihood of associated safety hazards.
• Risk Assessment Plan: It is recommended that owners include
provisions in the contract requiring contractors to submit a
risk assessment plan customized for the specific trenchless
project.∗ This plan should be reviewed and kept on file for
implementation and future reference. Contractor risk assess-
ment plan may include (see Table 9.3):
1. All work tasks/steps (identification of sequence of work
steps/tasks)
2. Hazards, concerns, and potential accidents (identification
of hazards for each tasks/step and site hazards that could
affect workers)
3. Controls, preventive measures, and boundaries (a list of
controls for each hazard)
4. Reference documents (a list of permits, operating manu-
als, and other reference procedures)

∗It should be noted that extent of this risk assessment plan must be in accordance
with the nature and size of the trenchless project.