4.1 Emitter spacing can range from six (6) to twenty-four (24) inches. The emitters used in the tubing shall be pressure compensating. Pressure compensating emitters have a relatively constant discharge rate over a wide range of pressures. Emitter flow rate shall be specified by the designer and stated on the system plans. The drip line pressure can range from 5 to 70 pounds per square inch (PSI).

4.2 Drip tubing shall be installed by one of the following methods: static plow, chain trencher or vibratory plow.

4.3 Static plow is the preferred method for inserting drip tubing into the soil. The static plow shall be pulled not pushed through the soil.

4.4 Chain trencher may be used for placement of the drip tubing in the soil. The maximum chain trench width is four (4) inches.

4.5 Wet soil shall not be plowed because of smearing.

4.6 Drip tubing installed in natural soil shall be installed to a depth of six (6) inches.

4.7 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 (1) to five (5) inches in the natural soil. Drip tubing shall not be placed in the capping fill material. In no case shall the cover over the tubing be less than six (6) inches.

4.8 Settled depth of the cap shall not be more than eight (8) inches. The capping fill material shall not contain more than 27% clay or 60% sand or 70% silt. Before the capping fill material is delivered to the proposed dispersal site, a textural analysis shall be provided. A credit of up to 50% of the settled cap depth may be allowed in the adjustment of the seasonal water table. The seasonal water table credit is at the sole discretion of the Department.