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| Water Quality Alarm Panel |
Date of test - 6th November 2011 |
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- Sample failed one or more thresholds |
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- Acceptable Water Quality |
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| Bevern Stream |
Longford Stream |
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A |
- Stoneywish Country Park, Ditchling |
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J |
- Longford Bridge, Spithurst |
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B |
- Ditchling STW Outflow |
Ridgewood Stream |
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C |
- Stocks Farm, Ditchling |
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K |
- Lewes Road, Uckfield |
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D |
- Swansyard Farm, Ditchling |
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L |
- A22 By-pass, Uckfield |
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E |
- Novington Lane, East Chiltington |
Cockhaise Brook |
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F |
- Holmans Bridge, Barcombe |
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M |
- Keysford Lane, Horsted Keynes |
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G |
- Clapper's bridge, Barcombe |
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N |
- Wildboar Bridge, Freshfield |
| Plumpton Mill Stream |
Upper Ouse |
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H |
- Uper Mill, Plumpton Mill Stream |
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O |
- Avins Bridge, Ardingly |
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I |
- Ferrings Bridge, East Chiltington |
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P |
- Deans Mill, Lindfield |
Summary of this months results
Although there had been enough rainfall during the previous week to raise river levels, the local streams returned to very low levels by the weekend 5/6 November. In the circumstances, it was no surprise to learn that November water quality results were no better than those measured in September and October. Dissolved oxygen levels were slightly higher in some places, slightly lower in others.
Levels of phosphate at Ditchling STW and Stocks Farm, although remaining extremely high, were slightly lower in November. By contrast, the site at Novington Lane had a much higher level of phosphate in November, the November value putting it into the extremely high category. Phosphate levels at Clappers Bridge and Ferrings Bridge on Plumpton Mill Stream site also remained extremely high this month. Elsewhere in the catchment, phosphate levels were extremely high at the two Ridgewood sites and at Avins Bridge on the upper Ouse.
Ammonia values were very high at Ditchling STW and remained high downstream at Stocks Farm. The effluent from the STW is receiving very little, if any, dilution because the stream above has dried back, and this is probably the main reason for the low dissolved oxygen measured at Stonywish, upstream of the STW. The regular dry back in Ditchling Stream upstream of the STW is a cause for concern; historically, this water was a perennial stream clean enough for swimming. Elsewhere in the catchment, ammonia values were similar to those measured in October – non-lethal but high enough to impact on sensitive species.
The condition of the waters surveyed is very poor for November; we can only hope that there will be an improvement when we finally get some decent rainfall.
Flow observations
Flow rates were moderate to very low with clear water and at some sites there was no detectable flow at all.
Our measurements
The graphs below show the values measured this month compared to the 12 month average for each of the 18 sites we test. For explanations on the S.O.C.S. designated thresholds values (shown on the graphs) and the EU Freshwater Fisheries Directive Mandatory and guide values please refer to our Introduction to WQ Testing page...
| Ammonia (N) - Values in mg/l |
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| Phosphate (PO4) - Values in mg/l |
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| Nitrate (NO3) - Values in mg/l |
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| Dissolved Oxygen (O2) - Values in mg/l |
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