NRA Thames 225 NRA National Rivers Authority Thames Region TR44 En v ir o n m e n t Ag e n c y NATIONAL LIBRARY & INFORMATION SERVICE THAMES Kings 'House. Kings Meadow 1, Reading RG1 8DQ V W A d ^ v a 2 - RIVER QUALITY July 1992 - June 1993 Susan Wattam Assistant Scientist Scientific Department October 1993 Telephone: (0734) 535422 ENVIRONMENT AGENCY 042726 CIRCULATION LIST Mr P Lloyd, Acting Environmental Services Manager (South-East) Mr J Haines, Environmental Services Manager (West) Mr B Walker, Acting Environmental Services Manager (North-East) Mr P Greaves, Senior Pollution Officer _ JM||g^hatfield, Principal Pollution Officer Mrs J Kinniburgh, Principal Quality Planner Mr J Eastwood, Principal Scientist Quality Regulation Dr R Sweeting, Regional Scientist Dr J Banks, Fisheries & Conservation Manager RIVER QUALITY REPORT (Period: July 1992 - June 1993) River Quality Objectives 572 sites were monitored to assess the 3820 km of watercourses that have quality objectives in the Thames region. Only 36 reaches (245 km or 6.4% of total) failed to meet their set objectives (see table 1). This continues the general trend of improvement, for eg, in the last period 52 reaches failed to meet their objectives and in the period before 62 reaches failed. 352 reaches (2248 km or 58.8% of total) achieved better than their objective. This is also an improvement on the last period when 300 reaches (1970 km or 51.6%) achieved better than their objectives. The length of river achieving class 1A has also increased since the last period - 1601 km (41.9%) compared to 1243 km (32.5%) previous. Table 2 shows all the reaches in each area with objectives and the class they achieved for the period. Table 2a is a matrix showing the total length of watercourse in each RQO class and the class achieved. Table 2b shows the length of watercourse that achieved its objective or above, and table 2c shows the length of watercourse achieving each class, regardless of objective. EC Freshwater Fish Directive (78/559/EEC) Thames region has 1470 km of watercourse designated as "fisheries" under the EC Freshwater Fish Directive. 504 km is designated as salmonid and the other 966 km as cyprinid. 173 sites are used to assess compliance against the standards set out in the directive. 7 salmonid and 2 cyprinid sites failed to meet the standards, which is an increase of 2 salmonid sites since the last report (see table 3). EC Dangerous Substances Directive (76/464/EEC) 5 freshwater sites failed to meet the standards set out in the directive (see table 4). Both of the total HCH failures are marginal and it is thought that the iron failure at Iveley Road is due to the natural geography of the area. One site has left the list since the last reporting period. The Tideway Table 5 shows the achievements of the 3 tideway reaches against their quality objectives for April - June 1993. Water quality was variable in the tideway during the period due to the alternating periods of sunshine and heavy rainfall. The periods of sunshine promoted algal growth in the tideway which caused diel variation in oxygen concentrations - dissolved oxygen levels varied between 70% and 120% saturation depending on time of day. The heavy outbreaks of rain caused significant inputs of storm sewage into the tideway which resulted in reduced oxygen concentrations. However, dissolved oxygen levels never fell below 40% saturation in the upper tideway. The middle tideway was generally satisfactory throughout the period, although a couple of notable incidents occurred involving Crossness STW. On 5 June Thames Water Utilities Ltd has to divert sewage into the tideway so as to facilitate emergency repairs. Approximately 200 TCM of sewage entered the tideway and dissolved oxygen levels fell to 30% saturation at the Crossness/Beckton reach. The second incident occurred as a result of operational problems at Crossness STW on 18 June. Ammonia levels peaked at 8 mg/1 along this stretch of the tideway and dissolved oxygen levels fell to 25% saturation. 5 sites on the tideway failed the standards as set in the Dangerous Substances Directive. 4 failures were for total HCH and 1 was for dissolved copper (see table 6). All failures were marginal with respect to the standards. Table 1 Reaches Failing /liieir Quality Objectives 1 July 1992 - 30 June 1993 Class Class Determining RIVER Reach Length (km) Sample Point RQO Achieved Failing Dets. BOURNE (BERKS) Chapel Row to Pang 7.600 BOURNE (BERKS) ABOVE PANG 1A IB DO/AmN BURCHFIELD BROOK Burghfield Cmn. to Foudry Brook 6.860 BURGHFIELD BROOK ABOVE FOUDRY BK 1A IB BOD DENTON BROOK Source to Cuddesdon STW 1.470 DENTON BROOK AT DENTON IB 2A AmN DDCLER Source to Hyde Mill Ditch 5.950 DKLER, DONNINGTON BREWERY 1A IB BOD ENBORNE Baughurst Brook to Kennet 6.050 ENBORNE, BRIMPTON GS 1A IB DO FILCHAMPSTEAD BROOK Dean Court to Thames 2.200 FILCHAMPSTEAD BK US THAMES IB 2A BOD GLYME Source to Woodstock STW 21.730 GLYME, WOOTTON 1A IB DO HARCOURT BROOK Stantn Harcourt to Limb Brook 2.870 HARCOURT BROOK ABOVE LIMB BROOK IB 2A DO KENNET AND AVON CANAL Croftn (Summit) to Kintbury 19.470 K & A CNL, FROXFIELD BR 1A IB BOD KENNET AND AVON CANAL Woolhampton to Ufton 4.450 K & A CNL, UFTON BR 1A IB BOD LERTWELL BROOK Ashbury to Tuckmill Brook 2.060 LERTWELL BROOK 150M BELOW ZULU BUI IB 2A BOD/ AmN LYDIARD BROOK Source to Rodboume Tip 3.700 LYDIARD BK DS STW LYDIARD MLCT 1A 2A DO/AmN OCK Longcot to Stnford itv STW 12.450 OCK, STANFORD-IN-THE-VALE BR 1A IB DO OCK Stnford itv STW to Bagpuize Brook 8.050 OCK. OCK BR LYFORD 1A IB DO PADWORTH STREAM Old Warren to Kennet 5.720 PADWORTH STREAM AT BRIDGE 386, PAD 1A IB BOD PANG Hampstd Norrcys to Bradfield STW 11.880 PANG, STANFORD DINGLEY 1A IB DO SUL Theale to Pangbourne STW 5.580 SUL, SULHAM BR IB 2A DO SUMMERSTOWN DITCH Summerstown to Cutters Brook 2.380 SUMMERSTOWN DITCH 100M BELOW MAR 2B 3 BOD/DO SWILL BROOK West Crudwdl to Flagham Brook 9.980 SWILL BROOK AT OAKSEY LANE 1A IB BOD/DO SWILL BROOK Flagham Brook to Thames 3.620 SWILL BK, PIKE CNR ASHTON KYNS 1A IB DO WHEATLEY DITCH Wheatley STW to Thame 0.280 WHEATLEY DITCH AT SUPERSTORE CAR P 2B 3 DO WOODH1LL BROOK Stockham Bridge to Childrey Brook 2.500 WOODHILL BROOK ABOVE CHILDREY BRO IB 2A BOD BOURNE (SOUTH) West End Common to Bourne 22.200 BOURNE S, MIMBR1DGE CHOBHAM IB 2A AmN LODDON Basingstoke STW to Lyde 4.580 LODDON, KEEPERS COTTAGE WILDMR IB 2A AmN VYNE STREAM Sherborne St.Jn to Bow Brook 4.160 VYNE STR DS VYNE LAKE IB 2A BOD WHITEWATER Source to Hart 15.570 WHITEWATER, DIPLEY 1A IB BOD RIVER QUALITY ASSESSMENT - Reaches Failing Their Quality Objectives 1 July 1992 - 30 June 1993 Class Class Determining RIVER Reach Length (km) Sample Point RQO Achieved Failing Dets. j j g g g i i g ?\^ \ v X s *r*i*Xs% W'X*. *W*!>»n«Xw 5s ► »»Xv 'iv BULBOURNE Northchurch to Gadc 9.700 BULBOURNE US GADE 1A IB AmN CATHERINE BOURNE Shenley STW to Minunshall Brook 3.250 CATHERINE BRN, RABLEY PK 1A 2A BOD GADE Great Gaddesdon to Bulboume 7.500 GADE, WTR END 1A IB BOD GADE Bulboume to Gade Avenue SWO 11.320 GADE/GUC, HUNTON BR 1A IB BOD GADE Gade Avenue SWO to Croxley Mill 1.810 GADE US CROXLEY CENTRE WATFORD IB 2A BOD GUC (CASSIOBURY REACH) Source to Gade 1.930 GUC (CASSIOBURY REACH) AT GADEBANK IB 2A BOD GUC (CROXLEY REACH) Source to Gade 1.970 GUC AT LOT MEAD LOCK IB 2A BOD GUC (PIX FARM REACH) Source to Bcrkhamsted STW 1.730 GUC US BERKHAMSTED STW IB 2A BOD MISBOURNE Lttle Missenden to Bury End Arm 6.260 MISBOURNE, LTL MISSENDEN 1A IB DO VER Dolittle Mill to Sopwell St. Alb 9.030 VER, GORHAMBURY 1A IB DO Table 2 DRIVER QUALITY ASSESSMENT - River Thames 1 July 1992 - 30 June 1993 Length Class Reach (km) Sample Point RQO Achieved Source to Swill Brook 11.15 THAMES, SOMERFORD KEYNES BR IB IB Swill Brook to Ccrney Wick Bk 3.55 THAMES, WATERHAY BR ASHTON IB 1A Cerney Wick Bk to Key 3.95 THAMES, CRICKLADE IB 1A Key to Ray 1.45 THAMES AT EYSEY IB IB Ray to Share Ditch 7.35 THAMES. CASTLE EATON 2A IB Share Ditch to Bydcmili Brook 3.82 THAMES, HANNINGTON BR 2A IB Bydemill Brook to Coin 2.87 THAMES, INGLES HAM 2A IB Coin to Shifford Weir 22.53 THAMES, BUSCOT INTAKE 2A 1A Shifford Weir to Bablock Hythe 12.41 THAMES, NEWBRIDGE IB 1A Bablock Hythc to Evenlode 7.97 THAMES, FARMOOR INTAKE IB IB Evenlode to Castle Mill Str 9.27 THAMES, TROUT INN GODSTOW IB 1A Castle Mill Str to Cherwell 1.36 THAMES, FOLLY BR OXFORD IB 1A Cherwell to Sandford Lock 4.41 THAMES, DONNINGTON BR OXFOR 2A 1A Sandford Lock to Ock 8.51 THAMES, RADLEY COLLEGE 2A 1A Ock to Thame 15.24 THAMES, DAYS LOCK IB 1A Thame to Goring STW 14.23 THAMES, WALLINGFORD BR IB 1A Goring STW to Whitchurch STW 8.50 THAMES US GORING WEIR IB 1A Whitchurch STW to Kennet 12.59 THAMES, CAVERSHAM WEIR IB 1A Kennet to Loddon 7.91 THAMES, SONNING WEIR IB 1A Loddon to Fawley Ct Str 7.59 THAMES, HENLEY BR IB 1A Fawley Ct Str to Cut 27.23 THAMES, COOK HAM BR IB 1A Cut to Bovency Weir 3.81 THAMES, BOVENEY IB 1A Bovency Weir to Romney Lock Cut 4.29 THAMES 400M DS BOVENEY DT IB 1A Romney Lock Cut to Windsor STW 5.77 THAMES, SUNNYMEADS INTAKE IB 1A Windsor STW to Wey 16.04 THAMES, NSWC INTAKE CHERTSE IB 1A Wey to Mole 10.53 THAMES, MWD WALTON INTAKE IB 1A Mole to Hogsmill 4.01 THAMES US RAVENS AIT SURBITO IB IB Hogsmill to Teddington 2.70 THAMES.