REPORT OF INVESTIGATIONS No. 40


River from the west. Since 1955, the water table adjacent to the river has
usually been below river level at the Chemstrand plant and water from
the river has infiltrated into the well field. Ordinarily infiltration from the
river would be a desirable feature as it would recharge the aquifer and
decrease the drawdowns. However, the Escambia River is salty part of
the time and infiltration introduces salt water into the sand-and-gravel
aquifer adjacent to the river.
 INDUSTRIAL WASTE DISPOSAL
 The complex problem of disposing of industrial wastes is very im-
portant because these wastes can pollute both surface and ground-water
supplies. A thorough knowledge of the geology and hydrology of an area
is invaluable in planning for safe disposal of industrial waste. Some in-
dustries in this area presently discharge wastes directly into streams,
bays and infiltration ponds.
 Disposing of waste into surface-water bodies may cause objectionable
odors, kill fish and plant life, discolor the water, and cause the accum-
ulation of solid waste materials. A knowledge of streamflow is very help-
ful in determining the dilution necessary to keep the concentration of
plant wastes below an objectionable level.
 Discharging industrial wastes into infiltration ponds may result in
 pollution of the sand-and-gravel aquifer because in most cases the water
 level in infiltration ponds stand above the ground-water level, especially
 when the ground-water level is lowered by heavy pumping. Thus, the
 pond has the head potential to recharge the aquifer. The permeability
 of the coarser sediments and presence or absence of clay layers help
 determine how fast water from infiltration ponds will move downward
 and then laterally.
 The disposal of industrial wastes into infiltration ponds occurs in the
 northern part of Pensacola. Concentrated acid wastes have been dis-
 charged into a pond for more than 70 years. This waste material has in-
 filtrated into the ground and moved with the hydraulic gradient. A di-
 luted form of this waste has been detected in the water from a Pensacola
 municipal well at 12th Avenue and Hayes Street, more than a mile from
 the pool. This well subsequently was abandoned. The average velocity
 of ground water was previously computed to be about 100 feet per year
 in the Pensacola area. Therefore, the acid wastes could move 6,000
 feet in about 70 years (an average of about 86 feet per year).
 A knowledge of the geology and hydrology in an area may prove use-
 ful to solve some problems of waste disposal. Information collected dur-
 ing this study enabled officials of the Chemstrand Corporation to in-