N.H. Code Admin. R. Env-Wq 1005.03

Current through Register No. 25, June 20, 2024
Section Env-Wq 1005.03 - Minimum Lot Sizes
(a) The minimum lot size for any lot shall be determined in accordance with this section.
(b) Minimum lot size, in square feet (ft2), and factors for sewage loading shall be determined based on soil groups and slopes as set forth in Table 1005-1 below, subject to the notes in (c) through (e), below:

Table 1005-1: Minimum Lot Size - Residential, 1 to 4 Bedrooms; Sewage Loading Factors

Soil Group[RIGHTWARDS ARROW]

Slope [DOWNWARDS ARROW]

1

2

3

4

5

6

0-8% orA/B

30,000 ft2

1.0

39,000 ft2

1.3

48,000 ft2

1.6

43,500 ft2

1.45

90,000 ft2

3.0

See (c)

8-15% orC

33,000 ft2

1.1

43,000 ft2

1.43

53,000 ft2

1.76

48,000 ft2

1.6

Not Applicable

See (c)

15-25% orD

36,000 ft2

1.2

46,800 ft2

1.56

62,000 ft2

2.08

52,000 ft2

1.73

Not Applicable

See (c)

25-35% orE

39,000 ft2

1.3

50,700 ft2

1.69

72,000 ft2

2.4

57,000 ft2

1.90

Not Applicable

See (c)

(c) Very poorly drained soils shall not be counted toward site loading to obtain subdivision approval.
(d) For purposes of determining minimum lot sizes, soil groups shall be as follows:
(1) Group 1 soils shall be well-drained to excessively well-drained soils with rapid permeability;
(2) Group 2 soils shall be well-drained soils with moderate permeability;
(3) Group 3 soils shall be moderately well-drained and well-drained with hardpan;
(4) Group 4 soils shall be bedrock relatively close to the surface;
(5) Group 5 soils shall be poorly-drained soils; and
(6) Group 6 soils shall be very poorly drained soils.
(e) Soil group shall be:
(1) Determined using the USDA-NRCS web soils survey (WSS), available at http://websoilsurvey.sc.egov.usda.gov; and
(2) Confirmed with one or more test pits dug as specified in Env-Wq 1006.
(f) For individual lots served or proposed to be served by an on-site ISDS and a public water system, the lot size shall be at least 50% of the size shown in Table 1005-1 or 20,000 ft2, whichever is larger.
(g) For lots having or proposed to have an on-site water supply with off-lot ISDS, the off-lot area shall meet the required lot size established in accordance with Table 1005-1. In such cases, the lot upon which the structure will be built shall be of sufficient size to accommodate the full protective well radius established by Env-Wq 1008.06.
(h) For lots that have or are proposed to have off-lot ISDS and off-lot public water system, local lot size regulations shall apply.
(i) Where ledge is encountered at less than 4 feet, Group 4 soil lot sizes shall apply.
(j) Manufactured housing park sites with on-site wastewater disposal shall be at least 10,000 ft2 multiplied by the factor listed in Table 1005-1.
(k) The minimum lot size for all other commercial and residential subdivisions shall be calculated by dividing the estimated daily flow (Q) of sewage in gallons per day by 2,000 and then multiplying by the sewage loading factor established in Table 1005-1, as indicated in the following formula:

Lot Size = (Q (gpd)/2,000 (gpd/acre)) x sewage loading factor

(l) For purposes of (b), above, Q shall be the estimated daily flow calculated in accordance with Env-Wq 1008.03(c) or 600 GPD, whichever is greater, except that for campgrounds that existed prior to January 1, 1993, Q may be calculated in accordance with Env-Wq 1008.03(b) so long as no additional lots are created.
(m) Each studio or 1-bedroom apartment shall be figured as 1.5 bedrooms for sewage loading purposes, where a bedroom represents a sewage loading of 150 gallons per day.

N.H. Code Admin. R. Env-Wq 1005.03

(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08

Amended by Volume XXXVI Number 41, Filed October 13, 2016, Proposed by #11184, Effective 10/1/2016, Expires 10/1/2026.
Amended by Volume XXXIX Number 06, Filed February 7, 2019, Proposed by #12716, Effective 1/24/2019, Expires 1/24/2029.