N.H. Admin. Code § Env-Dw 405.18

Current through Register No. 50, December 12, 2024

Section Env-Dw 405.18 - Sizing of Storage Tanks

(a) The criteria specified in this section shall apply to small community water systems and to those NTNC water systems whose reliability is directly important to public health as specified in Env-Dw 405.02(g).

(b) The required atmospheric water storage capacity for a water system with only one well shall be based on the safe yield of the well and the water system's design flow, as specified in Table 403-3 below:

Table 405-3: Requirement for Atmospheric Water Storage Capacity

For Water Systems That Have Only One Source

Groundwater Source Capacity	Atmospheric water storage capacity required
Peak flow	50 percent of design flow
2.5 times the design flow	75 percent of design flow
2.0 times the design flow	100 percent of design flow
Less than 2.0 times the design flow	Not acceptable

(c) The required atmospheric water storage capacity for a water system with more than one well shall be based on the safe yields of the wells and the water system's design flow, as specified in Table 403-4 below :

Table 405-4: Requirement for Atmospheric Water Storage Capacity

For Water Systems That Have More Than One Source

Minimum groundwater source capacity with largest producing well out-of-service	Atmospheric water storage capacity required
Peak flow	none required
2.5 times the design flow	25 percent of design flow
1.5 times the design flow	50 percent of design flow
Design flow	75 percent of design flow
Less than design flow	100 percent of design flow

(d) The required hydropneumatic storage capacity shall be 10 percent of total design flow .

(e) Pre-charged pressure storage tanks shall be accepted on an equivalent gross volume basis to conventional hydropneumatic storage. No more than 6 tanks of the pre-charged pressure type shall be permitted.

N.H. Admin. Code § Env-Dw 405.18

(See Revision Note at part heading for Env-Dw 405) #10612, eff 6-1-14