New York Codes, Rules and Regulations › Title 10 - DEPARTMENT OF HEALTH › Chapter - APPENDICES › Appendix 5-B › Table 2 - Standards for Well Casing, Grouting, Diameter, and Screens

Current through Register Vol. 46, No. 28, July 10, 2024
Well
								Diameter
Water-bearing
								Formation
Overlying
								Material
Minimum Casing length or
								Depth
1
Oversize Drillhole for Grout,
								Diameter
1
Casing and Grout
								Placement
1
Cased
								Portion
Uncased
								Portion
Well Screen
								Diameter
2
(where
								applicable)
1. Sand or gravel
Unconsolidated caving material; sand or sand and
								gravel
19' minimum; but 5' below pumping level
								3
None required
Grouting not required
2" minimum
Does not apply
2" minimum
2. Sand or gravel
Clay, hardpan, till, silt, or similar material to
								depth of more than 15'
5' below pumping level
								3
Casing size plus 2" if pressure placement of grout
								is used, Casing size plus 4" if gravity placement of grout is used.
								4,5,6
Upper drillhole shall be kept at least one-third
								filled with clay slurry while driving permanent casing; after casing is in the
								permanent position, annular space shall be filled with grout
								5
2" minimum
Does not apply
2" minimum
3. Sand or gravel
Clay, hardpan, till, silt, or similar material
								containing layers of sand or gravel within 15' of ground surface
5' below pumping level
								4
Casing size plus 2" if pressure placement of grout
								is used, Casing size plus 4" if gravity placement of grout is used.
								4,5,6
Annular space around casing shall be filed with
								grout
2" minimum
Does not apply
2" minimum
4. Creviced, shattered or otherwise fractured
								shale, limestone, igneous, metamorphic or similar rock types or
								sandstone
Unconsolidated caving material, chiefly sand or
								sand and gravel to a depth of 19' or more.
Through caving overburden
Non required
Casing shall be firmly seated in rock. Grouting not
								required
6" minimum
6" preferred
Does not apply
5. Creviced, shattered or otherwise fractured
								shale, limestone, igneous, metamorphic or similar rock types or
								sandstone
Clay, hardpan, till, shale, or similar material to
								a depth of 19' or more
Through overburden
Casing size plus 2" if pressure placement of grout
								is used, Casing size plus 4" if gravity placement of grout is used.
								4,5,6
Casing shall be firmly seated in rock. Annular
								space around casing shall be grouted.
6" minimum
6" preferred
Does not apply
6. Creviced, shattered or otherwise fractured
								shale, limestone, igneous, metamorphic or similar rock types or
								sandstone
Unconsolidated materials to a depth of less than
								19'
19' minimum
Casing size plus 2" if pressure placement of grout
								is used, Casing size plus 4" if gravity placement of grout is
								used.4,6
Casing shall be firmly seated in rock. Annular
								space around casing shall be grouted.
6" minimum
6" preferred
Does not apply
Notes for Table 2:
1 In the case of a flowing
				  artesian well, attempts should be made to install and seal the well in a manner
				  that protects the artesian aquifer, prevents erosion of overlying geologic
				  materials, and confines the flow to within the well casing, giving due
				  consideration to practicality, cost, and safety.
2 These diameters shall also be
				  applicable in circumstances where the use of perforated casing is deemed
				  practicable. Well points commonly designated on the trade as 11/4" pipe shall
				  be considered as being 2" nominal diameter well screens for purposes of these
				  regulations.
3 As used in this Table, the term
				  "pumping level" shall refer to the lowest elevation of the water in a well
				  during pumping, determined to the best knowledge of the water well contractor
				  taking into consideration usual seasonal fluctuations and drawdown.
4 Pressure placement includes
				  methods of grout placement using pumps and tremie tubes or using grout
				  displacement through the casing, or otherwise from the bottom up around the
				  casing, with one or more drillable plugs. When pressure placement is used with
				  a borehole diameter of only 2" greater than the casing diameter, casing shall
				  be assembled without couplings unless installed per the "Casing and Grout
				  Placement" technique described on Line "2" of this Table. Gravity placement
				  includes any method that relies on gravity to draw grout, either dry or as a
				  slurry, down into the annular space between the casing and borehole or between
				  an inner casing and outer casing.
5 For wells constructed by cable
				  tool, hollow rod, jetting, or other drilling method where the permanent casing
				  is driven, and where neither temporary casing nor an oversize borehole are
				  used, dry driven grout methods using granular bentonite may be used. These
				  methods use continuous feeding of granular bentonite into a starter hole or
				  continuous mounding around the casing as the casing is driven. Collar flared
				  joints or weld beads extending beyond the outside diameter of the permanent
				  casing shall be used with sufficient spacing to ensure that the grout seal is
				  continuous and extends downward into the saturated zone (i.e., beneath the
				  water table).
6 The oversized borehole for grout
				  placement should be as deep as necessary, based upon local hydrogeologic
				  conditions and potential contaminant sources, to prevent contamination from
				  entering the well. Grout should be placed along the full length of casing,
				  particularly where the presence of non-caving unconsolidated materials, coarse
				  gravel, or creviced, shattered, or fractured rock may result in pathways of
				  contamination to a well water system. Where this is not feasible because of
				  practicality, cost or safety, grout shall be placed at least to a minimum depth
				  of 19 feet. See also Note 1 to Table 1.