1. (a) Materials of construction for manholes shall be as follows:

   1. (1) Concrete for manholes and concrete grade rings shall conform to the requirements for class AA concrete in the New Hampshire department of transportation’s “Standard Specifications for Road and Bridge Construction”, available as noted in Appendix B;
   2. (2) Reinforcing for concrete manholes and concrete grade rings shall be steel or structural fibers that conform to the New Hampshire department of transportation’s “Standard Specifications for Road and Bridge Construction”, available as noted in Appendix B;
   3. (3) Precast concrete barrel sections, cones, and bases shall be certified by their manufacturer(s) as conforming to the ASTM C478/C478M-22 standard, available as noted in Appendix B;
   4. (4) The manhole frame and cover shall provide a 30-inch diameter clear opening;
   5. (5) The manhole cover shall have the word “SEWER” in 3-inch letters cast into the top surface;
   6. (6) The castings shall be of even-grained cast iron, smooth, and free from scale, lumps, blisters, sand holes, and defects;
   7. (7) Contact surfaces of covers and frames shall be machined at the foundry to prevent rocking of covers in any orientation;
   8. (8) Castings shall be equal to class 30 and certified by their manufacturer as conforming to the ASTM A48/48M-22 standard, available as noted in Appendix B; and
   9. (9) Brick masonry for shelf, invert, and grade adjustment shall be certified by its manufacturer as complying with the ASTM C32-23 standard, available as noted in Appendix B, clay or shale, for grade SS hard brick, with no more than 5 layers of brick for grade adjustment.

2. (b) Materials of construction for manhole grade adjustment shall be as follows:

   1. (1) Grade adjustment rings shall be constructed with either Grade SS hard brick that has been certified by its manufacturer as meeting the ASTM C32-23 standard, available as noted in Appendix B or reinforced concrete meeting the requirements of this section; and

   2. (2) Grade adjustment rings shall:

      1. a. Be sized to the opening of the manhole; and
      2. b. Not obstruct the access to the manhole.

3. (c) Mortar used in manhole construction shall comply with the following:

   1. (1) Mortar shall be composed of Type II Portland cement and sand with or without hydrated lime addition;

   2. (2) Proportions in mortar of parts by volumes shall be as shown in table 704-4:

      Table 704-4: Proportions of Cement, Sand, and Hydrated Lime

      Hydrated Lime

      Sand

      Type II Portland Cement

      None

      4.5 parts

      1.5 parts

      0.5 part

      4.5 parts

      one part

   3. (3) Cement shall be type II Portland cement that is certified by its manufacturer as conforming to the ASTM C150/C150M-24 standard, available as noted in Appendix B;
   4. (4) Hydrated lime shall be type S that is certified by its manufacturer as conforming to the ASTM C207-24 standard, available as noted in Appendix B;
   5. (5) Sand shall consist of inert natural sand that is certified by its supplier as conforming to the ASTM C33/C33M-24a standard, available as noted in Appendix B; and
   6. (6) Concrete for drop supports shall conform to the requirement for class AAA concrete of the New Hampshire department of transportation’s “Standard Specifications for Road and Bridge Construction” available as noted in Appendix B.

Source. (See Revision Note at chapter heading for Env-Wq 700) #8590, eff 3-25-06; ss by #10693, eff 10-15-14; ss by #14258, eff 7-1-25, EXPIRES: 7-1-35