(a)
- (1) Emitter spacing can range from six inches to twenty-four inches (6” – 24”).
- (2) The emitters used in the tubing shall be pressure-compensating.
- (3) Pressure-compensating emitters have a relatively constant discharge rate over a wide range of pressures.
(4) Emitter flow rate shall be:
- (A) Specified by the designer; and
- (B) Stated on the system plans.
- (5) The dripline pressure can range from five pounds per square inch to seventy pounds per square inch (5 psi – 70 psi).
(b) Drip tubing shall be installed by one of the following methods:
- (1) Static plow;
- (2) Chain trencher; or
- (3) Vibratory plow.
(c)
- (1) Static plow is the preferred method for inserting drip tubing into the soil.
- (2) The static plow shall be pulled, not pushed, through the soil.
(d)
- (1) Chain trencher may be used for placement of the drip tubing in the soil.
- (2) The maximum chain trench width is four inches (4”).
- (e) Wet soil shall not be plowed because of smearing.
- (f) Drip tubing installed in natural soil shall be installed to a depth of six inches (6”).
(g)
- (1) If capping fill material is used as part or all of the cover over the tubing, the installed depth of the tubing can range from one inch to five inches (1” – 5”) in the natural soil.
- (2) Drip tubing shall not be placed in the capping fill material.
- (3) In no case shall the cover over the tubing be less than six inches (6”).
(h)
- (1) Settled depth of the cap shall not be more than eight inches (8”).
(2) The capping fill material shall not contain more than:
- (A) Twenty-seven percent (27%) clay;
- (B) Sixty percent (60%) sand; or
- (C) Seventy percent (70%) silt.
- (3) Before the capping fill material is delivered to the proposed dispersal site, a textural analysis shall be provided.
- (4) A credit of up to fifty percent (50%) of the settled cap depth may be allowed in the adjustment of the seasonal water table.
- (5) The seasonal water table credit is at the sole discretion of the Department of Health.