The following safety requirements shall be established and shall apply to entry into or working in any confined space, more particularly sanitary collection system manholes, digesters or other underground structures:
A. Check Before Entry into Any Confined Space.
1. Make a visual check of the area to be sure that drifting gas or vapors will not enter the space to be entered.
2. Be sure that any lines connected to the space which may contain flammable, injurious or incapacitating substances are disconnected, blinded, or blocked off in a manner which that inadvertent reconnection of the line or removal of blind or blocking are effectively prevented. (This does not require the blocking off of laterals in sewers unless experience indicates that dangerous materials may be dumped into the sewer being serviced.)
3. Using the portable testing unit, test the air prior to opening manholes and within the space to be entered to determine whether dangerous air contamination and/or oxygen deficiency exists. The person making the test must log the time and date of the test indicating what was found in the log book kept with the testing unit. The testing person must initial each entry into the log book.
B. Entry into Space Where Tests Indicate that Dangerous Air and/or Oxygen Deficiency Do Not Exist.
1. Person entering the space must wear an approved safety harness with an attached line. The free end of the safety line shall be secured outside the entry opening.
2. Mechanical blowers shall be used to continuously blow air into the space entered and the air testing unit shall continuously monitor the air within the work space while the space is occupied. If the testing unit (by audible alarm or visual indicator) indicates a change to where dangerous air and/or oxygen deficiency exists, the person shall immediately vacate the work area. Whenever the space is vacated for any period of time, reentry into the space will not be made until the checks in subsections (A)(1), (A)(2) and (A)(3) of this section have been made.
3. An approved lifting device shall be over the entry and shall be ready for immediate use if an emergency rescue is necessary.
4. If the development of dangerous air and/or oxygen deficiency is apparent, no person shall be allowed to enter the confined space unless all the requirements of subsection (C) of this section have been followed.
C. Entry into Space Where Tests Indicate that Dangerous Air and/or Oxygen Deficiency Exists.
1. Mechanical blowers shall be used to blow air into the space to be entered until the dangerous air and/or oxygen deficiency condition no longer exists. If this addition of supplemental air is able to continuously maintain an atmosphere free of dangerous air and maintain a sufficiency of oxygen, a person may enter into and work within the space in accordance with all the requirements of subsections (A) and (B) of this section.
2. If supplemental air, provided as in subsection (C)(1) of this section, is unable to ensure an atmosphere free of dangerous air and/or oxygen deficiency, no person shall be permitted to enter the confined space unless all the requirements of subsection (D) of this section have been followed.
D. If an atmosphere free of dangerous air contamination and/or oxygen deficiency cannot be ensured through the use of additional ventilation, subsection (C) of this section, or the existence of an emergency where it is not feasible to the following additional conditions, shall apply:
1. Spaces shall be entered into through side openings if both top and side openings exist.
2. Only approved respiratory equipment shall be worn.
3. An approved harness type safety belt with an attached line shall be connected to a hoisting device provided for lifting the man from the area entered.
4. An additional employee shall stand by on the outside of the confined space ready to give assistance if necessary. This man shall have an approved respiratory device available for immediate use.
5. A third man (who may be assigned other duties) shall be within sight or voice call of the standby man.
E. Rescue Procedures.
1. Any person working in a confined space is required to wear an approved safety harness with attached safety line secured outside the work area. This rescue procedure shall detail procedures to be followed when the person to be rescued is wearing the required harness.
2. A rescue, or retrieval, of a person from a confined space shall be accomplished using the safety line attached to the harness worn by the person as rapidly as possible. If possible, observe while pulling to ensure that there is no binding or snagging of the person’s head, arms or legs. If such binding should occur, back off on the safety line and pull from a different pulling point.
If the air within the confined space has been tested in accordance with district requirements for such entry, and has been shown to be free of dangerous air contamination and/or oxygen deficiency, a second person, properly equipped, may enter the confined space to assist in the rescue; provided, that an additional person remains outside the space to monitor the rescue procedure and operate the lifting device if necessary.
3. Those district vehicles that will be involved in a rescue operation shall be equipped with the required breathing and lifting apparatus to accomplish a rescue in a confined space where testing indicates the existence of either a dangerous air condition and/or oxygen deficiency.
4. Under no circumstance are district employees to enter a confined space where a dangerous air condition and/or oxygen deficiency exist unless all the requirements for entry into such a space have been followed (subsection (D) of this section). In addition, and prior to entry, call the district supervisory control operator and give him your specific location, a brief description of the emergency and if “Fire and Rescue” and/or an ambulance should be called.