62-672.500. Inspections

Personnel or agents of the department may accompany inspectors on any inspection required by this rule, or inspect settling areas at any other time which is reasonable under the circumstances involved. They may also examine any inspection reports and be furnished copies thereof upon request.

(1) A completed new dam shall be thoroughly inspected prior to the deposition of industrial wastes above ground level behind it. Toe drains, spillways and water level control structures shall be certified by the design engineer as meeting all specifications of the design, and degree of compaction of the fill shall also be certified. Legible photographs, either aerial or ground, may be used to document this initial inspection, but shall not in themselves constitute certification. A complete file describing the items inspected and their condition shall be maintained by the owner, and a copy shall be furnished to the department prior to the above-grade deposition of industrial wastes behind the dam.

(2) Active dams shall be inspected weekly unless a defect has been disclosed, in which event the defective area of the dam shall be inspected daily until corrective maintenance has cured such defect. Inspections shall be made by employees of the owner of the dam who have been trained in accordance with subsection 62-672.500(9), F.A.C. The findings on each inspection shall be recorded, signed by the inspector, and filed after any necessary corrective action is initiated by supervisory personnel. The inspector shall travel on foot, horseback, or wheeled vehicle suitable for traversing the terrain involved at slow speeds. Dams shall be inspected from the crest and from the toe through the use of all-weather toe roads or other means of direct inspection from the toe of the dam. Items to be noted on weekly (or daily) inspections shall include:

(a) Condition of vegetation on dam and in area for fifty feet (50') downstream from the outside toe.

(b) Piezometric levels within the mass of the dam when instrumentation has been installed.

(c) Condition of soil surfaces on top and slopes of the dam and in area for fifty feet (50') downstream from the outside toe.

(d) Condition of drainage ditches in the area of the base of the dam.

(e) Liquid surface elevation and amount of freeboard. (This is to be recorded daily when limitations could be violated during a week of operations.)

(f) Condition of spillways and water level control structures, including all conduits exiting the dams.

(3) Retired dams shall be inspected monthly by a competent employee of the owner of the dam who has been instructed and tested by a qualified engineer regarding items to be checked. The findings on each inspection shall be recorded, signed by the Inspector, and filed after any necessary corrective action is initiated by supervisory personnel. Such inspection shall include:

(a) Condition of soil surfaces on the crest, slopes, and area fifty feet (50') downstream from the dam.

(b) Determination of piezometric levels within the mass of the dam while instrumentation of the dam has been determined to be necessary by an engineer.

(c) Determination of seepage characteristic through analyses of infra-red aerial photographs or thermal imagery when surveillance by such means has been proposed by the owner of the dam and approved by the department.

(d) Condition of Spillway and water level control structures, including all conduits exiting the dam, and any wooden structures which are subject to rotting.

(4) When a critical condition as listed in subsection 62-672.500(7), F.A.C., is suspected during a weekly or monthly inspection, the inspector shall ensure that a technical representative of the dam owner is made aware of the condition immediately. If the existence of the critical condition is confirmed, the department shall be notified immediately A written report of the condition and the actions proposed for its correction shall be made to the department within seven (7) days from the time existence of the critical condition is confirmed.

(5) Each active and each retired dam shall be inspected annually by a third-party engineer who is experienced in the field of construction and maintenance of dams. Costs for such inspections shall be borne by owners of the dams. One copy of the report pertaining to such annual inspections shall be furnished to the department, and the original of the report shall be retained by the owner. These inspections shall include:

(a) Analyses of seepage or other significant items shown on all aerial photographs of the dam which have been taken for any reason since the date of last annual inspection.

(b) Condition of soil surfaces on top and slopes of the dam and in areas for fifty feet (50') downstream from the outside toe.

(c) Review of all weekly, daily and monthly inspection reports to elevate the effectiveness of maintenance which was done to the dam during the period since the last annual inspection.

(d) Examination and interpretation of data obtained from any instrumentation installed in the mass of the dam.

(e) Condition of spillway and water level control structures, including all conduits exiting the dam and any wooden structures which are subject to rotting.

The annual inspection report shall include recommendations and corrective measures taken. If corrective measures are not completed by the time of annual submittal, then follow up inspections shall be conducted by the third-party engineer with quarterly project reports submitted until completion of all corrective measures.

(6) A retired dam which is to be abandoned shall be inspected by an engineer registered in Florida who is competent to determine that no further impoundment is being accomplished by the dam involved and that no further surveillance or maintenance is required. A copy of the final inspection used by the engineer for making his determination as above shall be furnished to the department, and a copy shall be retained by the owner of the dam. The department shall be notified prior to abandonment of any dam. Costs for such terminal inspections shall be borne by the owners of the dams which are to be abandoned.

(7) Any of the following items shall be considered as indicating a critical condition which requires immediate investigation and may require emergency maintenance action:

(a) Seepage on outer face or downstream from the toe in which there are boils, sand cones or deltas.

(b) Silt accumulations, boils, deltas, or cones in the drainage ditches at dam bases.

(c) Cracking of soil surface on crest or either face of the dam.

(d) Bulging of the downstream face of the dam.

(e) Seepage, damp area, or boils in vicinity of or erosion around a conduit through the dam.

(f) Any subsidence of the crest or faces.

(8) The following items shall be considered as indicating potential trouble areas which should be closely checked on subsequent inspections and repaired as necessary:

(a) Overgrowth patches of vegetation on downstream face or close area downstream from the toe.

(b) Surface erosion, gullying, or wave erosion of the upstream face of the dam.

(c) Surface erosion, gullying or damp areas on the downstream face of the dam, including the berm and the area downstream from the outside toe.

(d) Erosion below any conduit exiting the dam.

(e) Wet areas or soggy soil in downstream face of dam or in natural soil below dam.

(9) The owner of a dam shall provide annual training to all dam inspection personnel by an engineer experienced in dam design, construction, operation and inspection, and shall provide training to all appropriate employees in the implementation of the contingency plan required by Rule 62-672.550, F.A.C. The owner shall maintain records documenting such training.

(10) In the event of a dam failure which permits deleterious substances to enter waters controlled by the State or to cause other damages, the chairman of the Environmental Regulation Commission may convene at once a special panel of experts with experience in design and construction of earthen dams from government, industry, private engineering firms and/or educational institutions to gather data and to investigate the cause of the failure and to make recommendations for corrective actions. The owner of a failed dam shall take immediate action to arrest the flow of deleterious material when such is possible, and shall have that failed area of the dam photographed at the earliest practicable time. If feasible, the owner shall construct a coffer dam upstream from the failed area to impound materials. This will preserve the area of failure for detailed investigation, and thus contribute to factual data to be used in future safety considerations.

Specific Authority 403.061(22) FS. Law Implemented 403.061(22) FS. History–Revised 12-8-72, Formerly 17-9.05, 17-9.050, 17-672.500, Amended 6-28-99.