RBF_Cover (for eps) - National Water Research Institute

More documents

Recommendations

Info

Torgau Case Study The highly productive RBF scheme near Torgau in Saxony, eastern Germany, is situated within the Elbe River Basin. The basin is filled with Pleistocene deposits to a depth of 10 to 55 m that comprise interfingered glaciofluviatile sediments ranging from fine sand and silt to medium sand and gravel (Grischek et al., 1998). The deposits are overlain by Holocene river gravels (5- to 8-m thick) and meadow loam (2-m thick). The hydraulic conductivity values range from 0.6-2 × 10 –3 m per second. The Elbe River is in direct hydraulic contact with the aquifer. Riverbed clogging is low. The RBF system consists of 42 vertical wells arranged in nine well groups (Figure 1) and has a capacity of 150,000 m 3 /d. The distance between abstraction wells and the riverbank is about 300 m. The flow time of bank filtrate is between 80 and 300 days. The wells have a 20-m long filter placed in the lower layer of the aquifer at 30- to 50-m below ground surface. The site is well equipped with two sampling profiles along flowpaths between the river and abstraction wells, with monitoring wells in the landside catchment zone. 5712 5710 5708 5706 2.3* 2.0 3.2 2.6* 3.2 4.4 4.1* 1.7 3.1 I 1.0 1.0 3.1 II 1.2 1.9 2.6 2.7 III 1.3 1.1 3.0 1.0 1.4 4.1 0.8 3.3 1.0 0.9 IV 1.7 3.3 2.9 2.8 Mixed water DOC < 2.3 mg/L 1.1 0.9 2.8 0.8 Lakes 0.8 1.5 1.8 3.3 2.7 4.6* 2.8 3.0 5.1 Mixed water 4.2 DOC 2.3...3.0 mg/L Elbe River V VI VII 1.6 2.0 4.3 2.6 5.2 5.0 Mixed water 4.8 DOC > 3 mg/L Legend Abstraction well 3.7 3.2 3.0 3.3 1.9 1.7 4571 4573 4575 4577 Figure 1. Mean DOC concentration in milligrams per liter in groundwater in the catchment zone of the Torgau Waterworks from 1995 to 1997. The main aims of water-quality management include the maximum attenuation of organic compounds during aquifer passage and low concentrations of DOC, dissolved iron, and nitrate in raw water. Results from long-term monitoring programs and special field experiments provided an excellent database to draw conclusions on the effect of water-quality management measures. A detailed description of redox conditions and removal rates of organics is given in Grischek et al. (1998, 2000). Table 1 summarizes the effects of different management measures for the RBF site at Torgau. 2.6 3.2 4.4 4.4* Observation well with three sampling depths; mean DOC concentration in mg/L, 1995-97 Affected by local infiltration of surface water VIII 1 km IX 1.5 old branch 65
66 Table 1. Effect of Control Measures on Raw-Water Quality at the RBF Site in Torgau (Grischek, 2002) Control Measure Bank- Effect on Raw-Water Quality Filtrate DOC Trace NO3 – Fe 2+ NH4 + SO4 2– Portion Organics Mn 2+ Continuous operation of wells with increased abstraction rate Continuous operation of wells with decreased abstraction rate Periodic operation of selected wells Preferential operation of selected wells with favorable catchment area Operation of every second or third well within a group of wells Technical measure Change of the well filter depth ➚ ➚ ➚ ➚ — — — ➚ ➚ ➚➚➚ ➚ ➚ ➚ ➚ ➚ ➚➚➚ ➚ — — — — — — Effect is negligible or only temporary. Concentration increase. Concentration decrease. — Readily degradable and highly adsorbable organic compounds are attenuated in the biologically active riverbed. Long flow paths and long retention times of the bank filtrate in the aquifer allow further attenuation of poorly degradable and some polar organics. A field test was done to study the effect of an increase in water abstraction resulting in a decrease in retention time of bank filtrate in the aquifer. Over a period of 1.5 years, water abstraction from five selected wells was increased by about 40 percent. Excluding some slight changes in water quality near the bank line, no significant effect due to the decrease in retention time was observed. DOC removal and denitrification along the whole flowpath were not affected (Grischek, 2002). A continuous operation of selected wells has the advantage of lower concentrations of dissolved iron in raw water. High concentrations of dissolved iron were not measured in the bank filtrate, but were measured in the landside groundwater. Switching off the abstraction wells results in groundwater flow towards the river and the transport of dissolved iron into the aquifer zone between the wells and river. When the pumps are switched on again, higher iron concentrations are observed in raw water. Furthermore, periodic well operation leads to higher well clogging. A groundwater flow and transport model has been used to simulate the change of the well filter depth and its effect on groundwater flow, especially groundwater flow from the opposite side of the river beneath the riverbed to the wells. Due to the long distance between the wells and bank line, the effect was found to be negligible. A change in the filter depth should only be considered if the aquifer consists of layers with very different hydraulic conductivities and if the well is located at a short distance from the riverbank (the distance is less than aquifer thickness). Surprisingly, the most important factor was the selection of abstraction wells according to their catchment zone for landside groundwater. Based on the dense net of observation wells, it was possible to identify zones with different concentrations of DOC and dissolved iron in landside groundwater. Figure 1 shows the range of DOC concentrations in groundwater in the catchment zones behind the wells. — — — — ➚ — ➚ ➚➚ ➚ ➚ ➚ ➚ ➚ ➚➚➚
Page 1 and 2:
2RBF The National Water Research In
Page 3 and 4:
Published by the NATIONAL WATER RES
Page 6:
Foreword In 1999, the National Wate
Page 9 and 10:
vi 1:30 pm Session 3B: Hydraulic As
Page 11 and 12:
viii 1:15 pm Session 8: Emerging Co
Page 14 and 15:
Acronyms ADA ß-alaninediacetic aci
Page 16:
Conference Abstracts
Page 19 and 20:
2 conventional treatment train on c
Page 21 and 22:
4 The Louisville Water Company also
Page 23 and 24:
6 Treatment Capital Cost Annual O&M
Page 25 and 26:
8 design engineers needed to addres
Page 27 and 28:
10 Ohio River Pump Station Collecto
Page 29 and 30:
12 Figure 4. Wet/dry tunnel concept
Page 31 and 32: 14 The turbidity of well water is t
Page 34 and 35: Session 2: Operations Construction
Page 36 and 37: Land Surface lengths of well screen
Page 38: Summary Well systems can be constru
Page 41 and 42: 24 Traditionally, ASR has been used
Page 43 and 44: 26 plans for a pilot-scale bank-fil
Page 46 and 47: Session 2: Operations Evolution fro
Page 48 and 49: Today, Cedar Rapids obtains all of
Page 50: REFERENCES AND ACKNOWLEDGEMENTS The
Page 53 and 54: 36 source of most nitrate detected
Page 55 and 56: 38 Hallberg, G.R., D.G. Riley, J.R.
Page 57 and 58: 40 Two 10-MGD capacity pumps were i
Page 60 and 61: Session 3: Hydraulic Aspects Pluggi
Page 62 and 63: iverbed scouring. This analysis sho
Page 64: REFERENCES Schafer, D.C. (2003).
Page 67 and 68: 50 TS GWA Tegel TS Wannsee TS Tegel
Page 69 and 70: 52 contains the lowest concentratio
Page 71 and 72: 54 δ 18 O [ 0⁄00 versus Standard
Page 73 and 74: 56 Acknowledgements We would like t
Page 75 and 76: 58 Phase 1 Investigations Once the
Page 77 and 78: 60 pumping is discontinued and the
Page 80 and 81: Session 4: Siting Water-Quality Man
Page 84 and 85: The mean concentration in the “mi
Page 86 and 87: Session 5: Dynamics Using Models to
Page 88 and 89: source of induced infiltration to t
Page 90 and 91: affect the amount of contaminant en
Page 92 and 93: intuitive system behavior. In the c
Page 94 and 95: entering the well can be carried ou
Page 96: Ray, C., T.W. Soong, Y.Q. Lian, and
Page 99 and 100: 82 Riverbank Filtration Near Torgau
Page 101 and 102: 84 drinking-water quality. Drinking
Page 104 and 105: Session 5: Dynamics Temporal Change
Page 106 and 107: • Equalization of fluctuating con
Page 108 and 109: Session 5: Dynamics An Update of th
Page 110 and 111: Session 5: Dynamics On Bank Filtrat
Page 112 and 113: Figure 2. Streamlines for two wells
Page 114 and 115: well galleries near the Unterhavel
Page 116 and 117: Dinner Presentation Hydraulic Sensi
Page 118 and 119: conductivity k (especially of the r
Page 120 and 121: parameter value: Figure 6. Initial
Page 122 and 123: Keynote Presentation Riverbank Filt
Page 124 and 125: esulted in a significant improvemen
Page 126 and 127: Fritz, B. (2002). Uferfiltration un
Page 128 and 129: Session 6: Microorganisms Using Mic
Page 130 and 131: was independent of finished water t
Page 132 and 133:
Session 6: Microorganisms Transport
Page 134 and 135:
Session 6: Microorganisms Laborator
Page 136 and 137:
Cryptosporidium are unreliable, lab
Page 138 and 139:
Pathogen Concentration (pathogens/1
Page 140 and 141:
Session 6: Microorganisms Fate of D
Page 142 and 143:
treatment train optimized for turbi
Page 144 and 145:
Acknowledgements We gratefully ackn
Page 146 and 147:
Session 6: Microorganisms Assessmen
Page 148 and 149:
screens along the entire lateral le
Page 150 and 151:
Table 3. Average Distribution of Ri
Page 152 and 153:
Location Number of Sampling Events
Page 154 and 155:
Session 7: Organics Removal Riverba
Page 156 and 157:
uncontaminated groundwater could le
Page 158 and 159:
Sacher, F., H.-J. Brauch, and W. K
Page 160 and 161:
Session 7: Organics Removal Organic
Page 162 and 163:
TOC (mg/L) 9 8 7 6 5 4 3 2 1 Site 1
Page 164 and 165:
Conclusions RBF is very effective i
Page 166 and 167:
Lunch Presentation Potential Uses o
Page 168 and 169:
Session 8: Emerging Contaminants Re
Page 170 and 171:
H 3C O O N N H3C N CH3 Cl AMDOPH Be
Page 172 and 173:
Page 174 and 175:
Results and Conclusion The Santa An
Page 176 and 177:
Page 178 and 179:
echarge is not well understood. Our
Page 180 and 181:
Page 182 and 183:
The MS conditions were as follows:
Page 184 and 185:
Session 9: Public Policy and Regula
Page 186 and 187:
FEET 1,000 900 800 700 600 VERTICAL
Page 188 and 189:
The surficial aquifers in Midwester
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
that multiple samples should be eva
Page 196 and 197:
turbidity. Endospores, Giardia, Cry
Page 198 and 199:
Session 9: Public Policy and Regist
Page 200 and 201:
For the first phase of the Dyje Pro
Page 202 and 203:
Concentration mg.l 1 60 50 40 30 20
Page 204 and 205:
Session 11: Case Studies “Lessons
Page 206 and 207:
Concentration (mg/L) 35 30 25 20 15
Page 208 and 209:
REFERENCE Koterba, M.T, F.D. Wilde,
Page 210 and 211:
Page 212 and 213:
REFERENCES Laszlo , F., and Z. Homo
Page 214 and 215:
Page 216 and 217:
Figure 2. A sketch of the study are
Page 218 and 219:
By analyzing the δ 15 N-NO 3 of si
Page 220 and 221:
Page 222 and 223:
Microbial growth was weak in all la
Page 224 and 225:
Page 226 and 227:
Objectives The aim of the study was
Page 228 and 229:
6000 4000 2000 Suspended Solids (mg
Page 230 and 231:
REFERENCES American Public Health A
Page 232 and 233:
show all

RBF_Cover (for eps) - National Water Research Institute

Create successful ePaper yourself

Delete template?

Save as template?