| Name | Units | 25/1/95 | 20/2/95 | 22/3/95 | 24/4/95 | 19/5/95 | 21/6/95 | 17/7/95 | 17/8/95 | 19/9/95 | 16/10/95 | 8/11/95 | 6/12/95 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| pH | pH units | 8 | 8.2 | 8.5 | 8.2 | 8.4 | 8.6 | 8.3 | 8.4 | 8 | 8.2 | 8.1 | 8.1 |
| Turbidity | FTU | 28 | 8.3 | 4.2 | 5.9 | 3.3 | 5.3 | 4.5 | 10.3 | 5.3 | 6.7 | 6.2 | 20.9 |
| Temperature | °C | 6 | 7 | 8.5 | 9 | 12 | 20 | 19 | 23 | 16 | 15 | 8 | 4 |
| Conductivity at 25 °C | µsie/cm | 771 | 775 | 793 | 930 | 747 | 770 | 780 | 880 | 770 | 892 | 1000 | 970 |
| Dissolved Oxygen | % saturation | AE | 106 | 165 | 123 | 122 | 148 | 112 | 150 | 99 | 108 | 81 | 93 |
| Dissolved Oxygen | mg/l | AE | 12.9 | 19.3 | 13 | 13.1 | 13.4 | 10.4 | 12.8 | 9.78 | 10.9 | 9.62 | 12.2 |
| Biochemical oxygen demand+ATU.5days T | mg/l O | 1 | <1 | AE | 6.8 | 3.1 | 3.4 | 2.3 | <1.5 | 2.3 | 1 | 4.9 | 3.9 |
| Ammonia N | mg/l N | 0.26 | 0.16 | 0.06 | <.03 | <.03 | <.03 | 0.05 | 0.08 | 0.03 | 0.13 | 0.22 | 0.2 |
| Total oxidised nitrogen as N | mg/l N | 12 | 9.6 | 9.4 | 9.3 | 7.5 | 7.9 | 5.2 | 5.6 | 11.9 | 8.8 | 8.9 | 12.4 |
| Alkalinity CaCO3 | mg/l CaCO3 | 204 | 234 | 216 | 200 | 190 | 200 | 180 | 200 | 170 | 200 | 200 | 200 |
| Chloride | mg/l Cl | 42 | 43 | 47 | 62 | 55 | 59 | 57 | 68 | 54 | 83 | 81 | 60 |
| Phosphate sol.react | mg/l P | 0.27 | 0.32 | 0.67 | 1.2 | 1.16 | 1.5 | 1.8 | 1.8 | 1.1 | 2.8 | 3.6 | 1.2 |
| Sulphate | mg/l SO4 | 100 | 115 | 106 | 100 | 91 | 100 | 90 | 140 | 110 | 108 | 160 | 140 |
| Cadmium total | µg/l Cd | 0.1 | <.1 | <.1 | 0.1 | <.1 | <.1 | <.1 | <.1 | 0.1 | <.1 | <.1 | 0.1 |
| Selenium | µg/l Se | <1 | <1 | <1 | <1 | <1 | <1 | <1 | <1 | <1 | <1 | <1 | <1 |
| Chromium | µg/l Cr | 2 | 2 | 2 | 2 | <1 | <1 | <1 | 1 | 1 | <2 | 3 | 2 |
| Copper | µg/l Cu | 6.1 | 6.3 | 4.5 | 5.3 | 4.1 | 4 | 3.8 | 3.5 | 3.9 | 3.9 | 4.5 | 7.3 |
| Lead | µg/l Pb | 6.5 | 4.9 | 2.2 | 2.8 | 1.5 | 1 | 1.2 | 1.4 | 1 | 1 | 1.3 | 6.2 |
| Nickel | µg/l Ni | 6 | <5 | <5 | 5 | <5 | <5 | <5 | <5 | <5 | <5 | <5 | <5 |
| Zinc | µg/l Zn | 31 | 32 | 17 | 24 | 12 | 10 | 11 | 10 | 7 | 14 | 20 | 55 |
| Flow rate | m3/second | 7.874 | 3.598 | 1.903 | 1.386 | 1.032 | 0.678* | 0.663 | 0.513 | 0.856 | 0.662 | 0.525 | 1.348 |
Notes: FTU = formazin turbidity units. Standard suspensions of formazin are used to compare with river water. µsie/cm = microsiemens/cm. Biochemical oxygen demand+ATU.5days T = uptake of oxygen from a sample of river water over 5 days. * flow rate measured at Willen rather than Bletchley (which had been vandalised). [Willen and Bletchley flow rates were similar at other dates]