HomeMy WebLinkAbout2660021 - F.I. Received Doc. - Infiltration Rate at Drumbear
Infiltration Rate at
Drumbear, Co. Monaghan.
Client: HSE
RECEIVED: 25/08/2026
Trial Pit No. 1
Trial Pit
Local Landmarks RECEIVED: 25/08/2026
Dimensions of Trial Pit
1.5 m long x 0.7 m wide x 1.4 m deep
RECEIVED: 25/08/2026
Infiltration Rate Calculation
Graph – Depth of Water vs Time in Trial Pit
Depth of water during test = 75% - 25% empty
= (0.89 – 0.30) = 0.59 m
Vp = Length x Width x (75% empty – 25% empty)
Vp= 1.5 x 0.7 x (0.89 – 0.30) = 0.6248 m3
Ap50 = ((Length + Width) x 2) (75% empty – 25% empty) + (Length x Width)
Ap50 = ((1.5 + 0.7) x 2) (0.89 – 0.30) + (1.5 x 0.7)
= 3.6680 m2
Infiltration rate = Vp / (Ap50 x 75% - 25% empty time x 60)
= 0.6248 / (3.6680 x 4300 x 60)
= 6.60 x10-7 m/s
Soil Infiltration Test 1: Conducted on-site, yielding an infiltration rate of 6.602 x10-7 m/s
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
(Day
0)9.52
10.55 12.05 16.53 (Day
1)10.06
16.39 (Day
2)10.42
16.09 (Day
3)12.04
17.46 (Day 4)
11.35
Plot of Water Depth (m) V Time
Time taken to drop from 75% to
25% full depth = 4300 minutes
RECEIVED: 25/08/2026
Trial Pit No. 2
Trial Pit
Local Landmarks RECEIVED: 25/08/2026
Dimensions of Trial Pit
1.45 m long x 0.75 m wide x 1.5 m deep
RECEIVED: 25/08/2026
Infiltration Rate Calculation
Graph – Depth of Water vs Time in Trial Pit
Depth of water during test = 75% - 25% empty
= (0.99 – 0.33) = 0.66 m
Vp = Length x Width x (75% empty – 25% empty)
Vp= 1.45 x 0.75 x (0.99 – 0.33) = 0.7178 m3
Ap50 = ((Length + Width) x 2) (75% empty – 25% empty) + (Length x Width)
Ap50 = ((1.45 + 0.75) x 2) (0.99 – 0.33) + (1.45 x 0.75)
= 3.9915 m2
Infiltration rate = Vp / (Ap50 x 75% - 25% empty time x 60)
= 0.7178/ (3.9915 x 1050 x 60)
= 2.85 x10-6 m/s
Soil Infiltration Test 2: Conducted on-site, yielding an infiltration rate of 2.854 x10-6 m/s
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
9.54 10.55 12.05 16.43 (Day 1)12.39
Plot of Water Depth (m) V Time
Time taken to drop from 75% to
25% full depth = 1050 minutes
RECEIVED: 25/08/2026
Trial Pit No. 3
Trial Pit
Local Landmarks RECEIVED: 25/08/2026
Dimensions of Trial Pit
1.4 m long x 0.65 m wide x 1.6 m deep
RECEIVED: 25/08/2026
Infiltration Rate Calculation
Graph – Depth of Water vs Time in Trial Pit
Depth of water during test = 75% - 25% empty
= (0.95 – 0.32) = 0.63 m
Vp = Length x Width x (75% empty – 25% empty)
Vp= 1.4 x 0.65 x (0.95 – 0.32) = 0.5733 m3
Ap50 = ((Length + Width) x 2) (75% empty – 25% empty) + (Length x Width)
Ap50 = ((1.4 + 0.65) x 2) (0.95 – 0.32) + (1.4 x 0.65)
= 3.4930 m2
Infiltration rate = Vp / (Ap50 x 75% - 25% empty time x 60)
= 0.5733 / (3.4930 x 430 x 60)
= 6.36 x10-6 m/s
Soil Infiltration Test 3: Conducted on-site, yielding an infiltration rate of 6.362 x10-6 m/s
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
10.03 10.56 12.05 16.40 17.47 19.25 20.35
Plot of Water Depth (m) V Time
Time taken to drop from 75% to
25% full depth = 430 minutes
RECEIVED: 25/08/2026
RECEIVED: 25/08/2026