N R A - S o u t h W e s t i - 3 5

ENVIRONMENTAL PROTECTIONNationa Rivers Authority

South W est Region

ASSESSMENT OF THE IMPACT OF DISCHARGES FROM

MELDON QUARRY ON THE WATER QUALITY

OF THE WEST OKEMENT RIVER

JANUARY 1990 FWI/90/001

CORDON HMUY ISc Regional »*n«ral Manager

CVMDa/tot BScEnvtronrrv friol Protection Manager

JANUARY 1990

FWI/90/001

ASSESSME27T OF THE IMPACT OF DISCHARGES

FROM MELDCN QUARRY ON THE WATER QUALITY

OF THE WEST OKEMENT RIVER \

En v ir o n m e n t A g e n c y

NATIONAL LIBRARY & INFORMATION SERVICE

SOUTH WEST REGION

Manley House. Kestrel Way, Exeter EX2 7LQ

M R N NEWTONFRESHWATER INVESTIGATION UNIT NRA SOUTH WEST

MANLEY HOUSE

EXETER

ENVIRONMENT AGENCY

022073

ASSESSMENT OF THE IMPACT OF DISCHARGES FROM MELDGN QUARRY ON THE WATER QUALITY OF THE WEST OKEMENT RIVER

1. Introduction

On 16 September 1989 a fish mortality occurred in the West Okement River downstream of the main discharge points from the Meldon Quarry complex. The West Okement River had been experiencing extreme drought conditions during the summer of 1989 and the fish mortality coincided with the first significant rainfall at the end of the drought period.

Following the mortality an investigation was undertaken between 20 and 23 October 1989 to assess the effect of the major discharges from the quarry complex on water quality in the West Okement. The survey was carried out during the next period of significant rainfall following the fish mortality (see Fig. 2). Water quality has been examined in terms of compliance with applicable environmental quality standards (EQS) and general changes in quality.

The hardness of water is particularly important in determining EQS's for metals in List II of the Dangerous Substances Directive. In the West Okement River water hardness is very low (less the 50 mg/1 (CaCO^)).This makes the EQSf s for lead, zinc and copper exceptionally low.(See Appendix 1).

A biological survey of the effect of discharges from the quarry complex was also undertaken. Samples of aquatic macro-invertebrates were obtained by standard methods to assess the effects of the major discharges from the quarry complex during the drought period and following the initial significant rains when the fish mortality occurred in September.

The West Okement River has a River Quality Objective of National Water Council (NWC) Class 1A from its source to its confluence with the East Okement River.

The West Okement River has been designated under the EC Freshwater Fish Directive for the protection of salmonid fish from Meldon Reservoir to its confluence with the East Okement River.

The following use related objectives have been adopted for the West Okement River:

Protection of:

Aesthetic QualitySuitability for abstraction for potable supply Salmonid fishOther aquatic life/dependent organisms Livestock watering Crop irrigation

2 . Method

2.1 Water Quality Survey

Samples were obtained from the sites shown in Figure 1 in accordance with a programme defined by the East area Pollution Inspectorate. Specific site details are given in Table 1. Most samples were obtained manually, however some samples from sites 3,5 and 6 were obtained using automatic sampling equipment (samples obtained by this means are identified in Table 2).

2.2 Biological Survey

Samples of aquatic macro-invertebrates were obtained from 4 sites shown in Figure 1. Samples were obtained by standard kick sampling methods, the animals were identified to species level and estimations of abundance of each species was made.

3. Results

3.1 Flow Data

Relevant flow data is unavailable as the only flow gauging stations in the West Okement are upstream of Meldon Reservoir and imnediately downstream of the reservoir. As the reservoir was not overspilling during the survey period, this gauging station merely measured the compensation release from the reservoir. However, visual observation of flows in the Red-a-ven Brook and West Okement below the Red-a-ven confluence indicated flows considerably increased during the survey period.

3.2 Rainfall Data

Rainfall data for the relevant period is shown in rig. 2 for stations at N. Wyke NGR SX 661983 and Higher Brockscombe NGR SX 462950. Normally the site at Okehampton Pleasure Gardens would be used for rainfall information. However, the gauge developed a fault during the survey period. Higher Brockscombe is in the R. Wolf catchment 10 km to the North West of Meldon Quarry and North Wyke is 10.5 km East North East of Meldon Quarry in the Taw catchment. These two sites are the nearest to Meldon Quarry with a constant readout of rainfall. However, these sites do give some indication of the rainfall occurring in the area at the time.

3.3 The results of chemical analyses of relevant parameters at the sites examined are shown in Table 2.

Changes in quality of pH, aluminium, zinc, nickel, copper and cadmium are shown graphically for sites 3,5 and 6 in figures 3-8 respectively.

3.4 The species composition of samples obtained during the biological surveys are shown in Table 3.

Discussion

West Okement River below Weldon Dam

Water Quality was found to be good in the West Okement downstream of Meldon Dam. The West Okement immediately below Meldon dam complied with the Environmental Quality Standards for pH, copper, nickel, zinc, lead, cadmium and aluminium and water quality was Class lA.

Red-a-ven Brook

Three samples were taken from the Red-a-ven Brook, a tributary of the West Okement River. Quality was originally good when sanpled on 18 and 20 October, but suffered from a depression in pH on 22 October which caused the EQS for pH and the tentative EQS for aluminium to be exceeded. The cause of this change is not known positively but it is likely to be due to natural moorland run-off following rainfall after a long dry period. However, as there are both disused mine workings and part of the Meldon Quarry complex is in the catchment of this brook, it is possible that these factors influenced water quality changes.

West Okement at Meldon viaduct

Water quality in the West Okement at Meldon Viaduct showed exceedance of the EQS's for pH, Zinc and Aluminium. The EQS for zinc was exceeded by only a small margin.

The reason these EQS's were exceeded is not known and it is impossible to determine if the Red-a-ven Brook was a major contributor due to inadequate data. Previous surveys have identified the presence of an input of zinc and copper and nickel to the West Okement River between the Red-a-ven confluence and the Meldon Viaduct. However, before the small inputs could be investigated many had dried up under receding flows.It*is likely that the EQS for copper was also exceeded at this site as total values exceeded the EQS by small amounts. Although analysis was not undertaken for dissolved copper on the majority of samples it is likely that most of the total copper was in dissolved form based on evidence from other sites.

Youlditch Stream

One sample was obtained from the Youlditch Tributary on 29 October, this tributary enters the West Okement immediately upstream of Meldon Quarry drainage tunnel. This sample was taken after the main survey period. Quality was good except for the concentration of zinc which exceeded the EQS.

West Okement 50m downstream of Meldon Quarry drainage tunnel

Samples from the site 50m below Meldon Quarry drainage tunnel exceeded the EQS for pH, zinc and cadmium. Due to the limited data on dissolved metals it is inpossible to determine whether the EQS's for copper, nickel and aluminium were exceeded. However, in the two samples where dissolved metals were analysed, the majority of these metals were found to be in the dissolved form and as such the EQS's for these metals are likely to have been exceeded.

Cadmium showed a significant increase in concentration at this site with values almost an order of magnitude above the EQS despite the fact that concentrations were below the limit of detection at the upstream site.The source of the metals seems likely to be the drainage .tunnel from Meldon Quarry although there are no data available on the quality of water leaving the tunnel to assess this.

Meldon Quarry Stream

The Meldon Quarry Stream was found to be very poor quality with a low pH and high metal levels, particularly copper, nickel# zinc, cadmium and aluminium. Hardness and conductivity were also very high. The Meldon Quarry Stream is essentially derived from ground and surface water drainage from part of the Meldon Quarry site. The activities of quarrying are exposing pyritic shales which are oxidising to produce acid. The low pH of the water is assisting in leaching metals from the strata of the quarry complex. Consequently the water draining the quarry area is rich in the metals present in the geology of the site.The Meldon Quarry Stream has no designated use and therefore BQS's are not applicable.

West Okement River below Meldon Quarry

The West Okement River 200m downstream of Meldon Quarry Bridge is downstream of the discharge point of a road drain which receives the Meldon Quarry Stream. Three samples were taken at this site during the survey period. The EQS's were exceeded for pH, copper, zinc, nickel and aluminium. In the two samples that were comparable with samples taken upstream at the same date and time, it would appear that cadmium concentration had decreased at this site whilst copper, zinc, aluminium and nickel concentrations had been further increased, probably as a result of the discharge of the Meldon Quarry Stream. However, the contributions of general road drainage and the land drains which discharge into this drainage system were not recorded.

Biological Survey

Biological samples taken from the West Okement during the drought period upstream of the main quarry discharges showed a typical moorland aquatic invertebrate community to be present, and little change was detected in this community after the first rains in September when the fish mortality occurred.

Downstream of Meldon Quarry drainage tunnel little effect was detected on the invertebrate community, either before or after the initial rains at the end of the drought although significant iron deposition had occurred in the river downstream of the drainage tunnel discharge.

Downstream of the Meldon Quarry Stream discharge point a severely restricted invertebrate fauna was present both before and after the initial rains which coincided with the fish mortality in September. The fauna at this site was consistent with a community resulting from the influence of significant toxic pollution.

5. Conclusions

5.1 Upstream of the main discharges from Meldon friarry complex the EQS's for pH and zinc were definitely exceeded although zinc only exceeded the EQS by small quantities. It is likely that copper also exceeded the EQS above the main quarry discharges by small quantities but the data are insufficient to determine this. Aluminium is also likely to have exceeded the EQS value which has tentatively been suggested for this metal but again the data are insufficient for confirmation.

5.2 In the West Okement River downstream of the main discharge from Meldon Quarry, those parameters found to exceed their EQS's at the upstream site continued to exceed their EQS's but by greater margins. Concentrations of nickel were also found to exceed the EQS downstream of the quarrycomplex.

5.3 Downstream of Meldon Quarry drainage tunnel the EQS for cadmium was exceeded in the West Okement River but concentrations had apparently reduced below the EQS in the West Okement River 200m downstream of Meldon Quarry Bridge.

5.4 Concentrations of zinc, copper, nickel, aluminium, conductivity and hardness significantly increased in the West Okement River downstream of the main quarry discharges.

5.5 Biological monitoring of the West Okement River showed a significant effect on the aquatic invertebrate fauna downstream of the main discharges from Meldon Quarry. The fauna present downstream was typical of a community experiencing severe toxic pollution.

6 . Recommendations

6.1 The discharges from Meldon Quarry should be consented so that quality controls can be imposed and limits applied to protect designated uses in the West Okement River.

6.2 The problem of EQS exceedance which is occurring upstream of the main discharge points of the Meldon Quarry complex should be taken into account when producing the Water Quality Management Plan for the River Torridge catchment.

\LH\REPS 9 0\MN15-1

FIGURE 1

MONITORING SITES FOR TOE ASSESSMENT OF THB EFFECTS OF HBLDON QUARRY ON THE WATER QUALITY OF THE WEST OKEMENT

YOULDITCH STREAM

KEY

CHEMICAL MONITORING SITES

BIOLOGICAL MONITORING SITES

A30Road drain

MELDON QUARRY STREAM

RED-A-VEN BROOK

MELDON DAM

Fig. 2

Rainfall (mm)20

15 -

10 -

5 —

Rainfall (mm)

12.00 24.00 12.00 24.00 12.00 24.00 12.00 24.00 12.0018.00 06.00 18.00 06.00 18.00 06.00 18.00 06.00

Time (hrs)

| Rainfall at H Brockscombe || Rainfall at N WykeRafnfefl 3 hourly Intervals

• * • • • • • • • • •FIG. 3

pH v Tnme (hrs)pH

TimeMeldon Viaduct 50m d/s of tunnel Meldon Quarry Stream

Pit. 4 • • • • • • • •

Total Al v Time (hrs)Total Al mg/l

TimeMeldon Viaduct 50m d/s of tunnel Meldon Quarry Stream

• #FIG. 3

Total Zn v Time (hrs)Total Zn mg/l

12.00 18.00 24.00 06.00 12.00 18.00 24.00 06.00 12.00 18.00 24.00 06.00 12.00

Meldon Viaduct

Time50m d/s of tunnel Meldon Quarry Stream

Total Ni v Time (hrs)Total Ni mg/l

TimeMeldon Viaduct 50m d/s of tunnel Meldon Quarry Stream

Total Cu v Time (hrs)Total Cu mg/l

TimeMeldon Viaduct 50 d/s of tunnel Meldon Quarry Stream

• • • • • • • • •FIG. g

Total Cd mg/l v Time(hrs)Total Cd mg/l

0.1

0.05

0.02

0.01

0.005

0.002

0.001

0.0005

0.0002

0.000112.00 18.00 24.00 06.00 12.00 18.00 24.00 06.00 12.00 18.00 24.00 06.00 12.00

Time

E O S C d - suafl (D.005mg/I)

Meldon Viaduct 50m d/s olf tunnel Meldon Quarry Stream

: 20th O ct 21 at O ct 22n d O ct 23rd O ct

^ ^ ^ \----------------

: V t ~ ........./1

r t ■ : ! \‘ / \

11

-------- ------- ------ ------- -----

\. i \

i \

11

1 ------------------------------- -------------------------------

E Q S « 5ugA

-

-

I ..... I 1 1 1 1 ,1 ______ 1________ 1 1

TABLE 1

C H B H C A L S A M P LIN G P O IN T S

Site No. Description NGR

X.2. 1 :3.4. :* tk5.6.7. “V

W. Okement below Meldon Dam ' Red-A-Ven Brook prior to confluence with W. Clement

W. okement at Meldon viaduct ' Youlditch Stream prior to confluence with W. Okement

H. Okement 50m d/s quarry drainage tunnel ' / Heldon Quarry Stream prior to road drain

W. Okement 200m 6/s Meldon Bridge

SX 563917 SX 566920 SX 565924 SX 564928 SX 565932 SX 568928 SX 566934

BIOLOGICAL SAMPLING POINTS

Site No. Description NGR

3. W. Okement at Meldon Viaduct (as G*em. site 3) SX 5659248. w. Okement 100m u/s Meldon ftiarry drainage tunnel SX 5659285. W. Okement 50m 6/s quarry tunnel (as Chem. site 5) SX 5659329. W. Okement 150m 6/s A30 roadbridge SX 566931

\LH\REPS90\MN12-1

TABLE 2 Results of selected Water Quality determinands West Okenent River 18 September 1989 - 29 October 1989

SUt I BELOV tfEIMN D M K S T QWKHT

Da a /r im pH

f05*css Cu agfi

TotalCu n$(t Pb wg/l

To tu t Pb ng/t JU mg/l

Total IU ug/t A« mg/1

Total A* iig/t

Total 2r uglt

Total Cd «>g/l

v u *Al *9I t

Total At «g/l

U.09 10 50 u * - <.005 <.005 < M <.008 <.005 <.005 - - .009 <0.0001 .021 .177

JO.JO 1400 6.5 50 3 <.005 <.005 (.001 <.000 <.005 <.005 - <.0f <.005 <0.0001 . 6; .J9f

22.10 t m 6.6 11 4 <.005 .001 <.001 <.001 <.005 <.005 - <.0f 0. 16 <0.0001 .133 .190

■

,

, ,1I fi

1i

11

1i

* '

I L H U 48LES1MM-!

•SUt

• •J NELDON VIADUCT IffST drCNCRT

• • • • • • • •

Da U l f05#C D lM Total Total DU4 Total 0144 Total Total Total OU4 TotalJiat pH Cond SS Cu «9/l Cu *9/7 Pb W$fl Pi »g/t m *g/l U »9I t *4 flty/l *4 *9/1 U ng/l Ctf i9/I Al *$/t At 1 9 / 1

70.10 7415 71 (5 (.005 <.005 <.008 <.001 <.005 <.005 - <.07 .070 0.00070.0007

. roj .779 Saipltrf by PI

20.10 MOO - - - .010 - <.001 - <.005 - - .037 <0.0007 - .177 AutoSaiplu

' ■ MOO - - - .001 - <.001 - .006 - - .021 <0.0007 - .773 «

■ 7100 - - - .009 - .Of J - .008 - - .040 0.0007 .945 w

' ' 2359 r - - .009 - <.001 - .009 - - .057 <0.0007 .404 *

2 7 . 1 0 oioo - * . m - <.008 - .oro - - .043 <0.0007 .368 i

• 0900 - - - .001 - <.008 • .013 - - .054 <0.0007 .410 f

• 1700 * - - .007 - <.001 * .o n - - .054 <0.0007 .378 a

■ • . 7500 - ♦ .00* - <.008 .0/5 - - .050 <0.000/ .374 a

■ ■: w o ««B - - <.005 - <.001 - .0f6 - - .041 <0.0007 .255 »

: ■ i m 9» V - - <.005 - <.001 - .015 - - .047 <0.0007 .239 m

• : 2359i i !■- - - <.005 - <.001 - .07$ - - .047 <0.0007 .799 t

i2 . ro ojooi i 9» J - - <.005 - <.001 - .075 - - .040 <0.0007 .in1

*

;; •; omo 6.4n

- : - <.005 - <.008 - .073 * - .O il <0.0007 .777 »

: ■ : w o v • C - - <.005 - <.001 - .072 - * .039 <0.0007 .254 »

■ B ! 1200,t i * • ¥n - • <.005 * <.001 - .072 - • .041 <0.0007 .359 ft

I

ipn*n»t)i umx

i$M aacxu

waiu (

SlU• • • •i rwinrcH n n mat n cmifivcke « m H$r oanar

Data/

Tim pH Condt o w

SS

U44Cu •'jit

Total

Cu avg/r

Dt44

Pfc «9/t

Total

Pb »9ItlUu

u »9itTotal

m »g/t

0444

A* *9/1Total A4 19/t

Total

In milt

TotalCd Milt

DU4

U ft

Tout

U 1ij/l

79.10 tin 6.1 159 24 <.005 .OfO <.001 <.001 0.01! 0.016 - - .13 f 0.001t . m .<00

'

• » 1

i ■ 1

"

"

i

1 II1

1 " [

, ,,1

I

U H | r « t f S | W I 5 - l

s a t• *

S VEST OrE*E*r SQM D/S OF WELDON• • •

Q M W DRAINAGE T U m i W9MJ3

Date/fiit P« Cond

f05#CSS

IU44Cu 09/I

Totai Cu ag/l

0444 P6 »gI t

Total Pb «9/t

0444Hi tig/1

Total Ni mg/l

0444 h m9/i

Total A4 mg/l

Total In ig/ I

Total Cd *9/1

VU4hi ttg /l

Total U 199/I

70/10 1438 n 7 0.006 0.006 <.00! <0.001 0.011 0.0f9 - <0.0/ 0.013 <0.0001 O./fS 0./87Suptc

20/m 1500 - - - <0.005 - (0.00S - 0.079 - - 0.043 0.0m - 0.112 AutoSanpU

I too 6. a - - <0.005 - <0.008 - 0.036 - - 0.064 0.0453 - 0.744

7/00 6.0 - - <0.05 - <0.08 - 0.06/ - - 0.748 0.0336 - Ml

2359 5.4 - * <0.05 - <0.08 - 0.054 * - 0.085 0.0504 - 0.759

21/10 0300 5.2 * - 0.009 - <0.008 • 0.046 - - 0.095 0.0460 - 0.7/3

0600 s.r - - 0.170 - <0.008 - 0.056 - - 0.109 0.0247 - 0.760

0900 5 .2 - - <0.05 - <0.08 - 0.055 - - 0.09/ 0.0/58 - /. 30

1200 5.2 * - 0.014 - <0.008 - 0*0/4 - - 0.171 0.0166 - 0.955

1500 5.5 - - 0.10 - <0.008 - 0.059 - - 0.(03 0.0/29 - 0.647

noo 5.9 - - <0.05 * <0.08 - 0.096 - - 0.096 0.0270 - 0.786

2/00 6.7 - - 0.009 - <0.08 - 0.059 - - 0.098 0.0017 • 0.474

, JJ59 6.3 - * 0.009 - (0.01 - 0.059 - - 0.098 0.0077 - 0.449

22/10 0300 4.4 > • 0.01 f - <0.08 - O.OS7 - - 0.098 0.0068 - 0.46/

: 0600 6.5 :i- • 0.009 - <0.08 - 0.063 - - 0./06 0.0064 • 0.415

0900 6.0 - - o .o r r - <0.00J - 0.07/ - - O .ttl 0.004J - 0.663

\ J

I

SUt• • • t 9

5 vest o r o o r son p /s o f n e u m q m w v dkamage r o m i m9W JJ

• #

(Continued)

Odti/Tim pH Cond

I05*Css

Dl44Cu w il l

To ta t Cu »g/7

0144Pb »9f t

ToUt P6 ag/l

0U4 7U 119/I

Total Hi mg/I

(U44a* 09 a

Tout A4 99I I

ToUt Zpi ■ j/l

Total Cd *g/l

0144At w$ft

Total At 119/I

77 00 5.7 - - - 0.016 - <0.008 - 0.061 - - 0. (78 o.ofto - 0.738

1745 5.0 98 8 0.014 0.0(4 <0.008 <0.008 0.095 0.19 4 - <0.01 0.753 <0.007 0.777 7.73 Manuat SiMpU .

1500 5.3 - - - O.OfJ <0.008 • 0.061 - - 0. f 08 0.0743 0.677

noo 5.5 - - - 0.017 <0.001 - 0.068 - - 0.140 0.0736 0.667

7700i 5./ - - - 0.008 <0.008 - 0.046 - - 0.087 0.0777 0.606

7359 5.6 * - - 0.009 <0.008 0.034 - - 0.058 0.0709 0.476

73/10 0300 5.6 - - • 0.007 <0.008 - 0.037 - - 0.051 0.0773 0.474.

73.(0 06.00 5.1 - • - 0.007 <0.008 - 0.037 - - 0.057 0.0707 0.437

09.00 5.1 - - - 0.008 <0.08 - 0.030 - - 0.053 0.0094 0.396

17.00 5.1 - - - 0.070 <0.08 - 0.033 - - 0.065 0.0709 0.477

uum

ism h

iu m

own

oj wiu

wins

iiwni

imiu

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3 ^n. a.

9 »

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3 ? *o

«*>•

O

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1 5 i t

2 ?

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o

* 0

|

«*•

«N*O

«**

«niO

•"*

K >

«xO

»*

r> t e*g***«N|

3 S*o

r-*j

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Vi »

• 3 *c» <«

1 ■ 1 1 1 > « t i t • «

3 ST

►2 ^*n — — — -

f o>

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i 1 1 1 • 1 • 1 « I i i 1

w

3 s*

ACk.

«*»

Np' N#- •w V*

O O

s*

ofn

°V

«x>

3 *O A

Gk.

»*>F*»

1 ♦ i ► • « 1 i • •

< 3 ?O

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«"*- - - -

O*- - - - - -

tA

w

3 >B 3

U

fS*r*»»»•*

» i fl

(Jm»a </>O V)

r 1 • 1

-*f«oo

• 1 1 » 1 1 1 1 1 i i » ( I

acA.

5 «5 2

<=»

c** «N*

o

■n*

«N»

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18

c***

1

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m

• • • • • • •su» i iridm w «*r t m u m ot to m i l i t i a n n n s r o iu u t ic e n tu iu ii

• • • •

Data/Tim pH Cond

705*CSS

DU4 Cu »g/l

Total Cu »g/7

DU*Pb *9/1

Total Pb *g/l

W u Ni «g/t

fatal Nt «gI t

Du* k i >9 / 1

Total JU *g/l

Total 2* igI t

TotAt Ci ■s/l

Pil4At *9 / 1

Total At *9 / 1

• 7233 3.1 9 79 47.0 .$61 .675 .077 .0(5 2.07 2.66 - 6.07 4.07 0.0715 74.2 17.5 Siiplid by PI

- MOO 3.7 - - - .137 - <.01 * 2.66 - - 4.30 0.0269 23.0

• n o o 3.7 - - - .791 - .022 * 2.91 - - 3.17 0.0306 23.0

' 2100 3.6 - - - 1.771 - .015 - 3.30 - - 4.09 0.0312 26.0

■ 23Sf 3.; - - - .625 - .037 - 3.77 - • 4.75 0.0327 27.0

2 3 .70 0300 3.; * - - .175 - .017 - 3.07 * - 3.53 0.0379 23.0

■ 0600 j.; • - - .959 - .071 - 4.50 - - 4.49 0.0335 24.6

• otoo 3.; - - - .747 * <.01 - 2.97 - - 4.96 0.0272 24.7

• 1700 3.1 - - - .770 - <.001 - 3.74 - - 4.29 0.0329 - 26.5

|U t|M S tfS tM !5 - l

• • • • • osu* r kst omur iom NwsmM of xiiwi (u«m sntEM umn

• • • • •

DaU fTim pH Cond

705'CSS

Q lu Cu i9/1

fatal Cu ig/l

Dtw Pb »9/t

Total Pb »9 I t

VU*Hi 1 9/i

Total Hi «9/i

O iM *4 «9/i

fotai h «9 f t

fatal In 1 9 f t

fatal Cd «9/t

D lU Al i9/I

fetal i t 1 9/I

fl.09 MI5 5.0 - - .045 .045 <.001 <.001 .167 .799 - - j r o 0.0074 .977 2.51

io.ro moo 4.4 742 6 .017 .071 <.001 <.001 .194 . 7 f l - <.0t .1/0 <0.0007 .074 .199

J7.I0 1222 5.7 H I n .011 .024 <.001 <.001 .090 .097 • <.01 .177 o . o o n .455 7.05

UH|r«lES|MfS-l

Table 3. Results of Surveys of invertebrates on the West Okement River 9 September and 20 Septenber 1989.

Abundance Rating

TaxaSiteSample*

3 8 5 9a b a b a b a b

2 1 3 2 2 2 11 2 1 1

1

12 2 3 2 3 22 2 3 2 1

2 3 2 3 2 12 2 2 2 22 1 2

3 2 2 2 22 1

1 1 2 2 2 21

1 2 1

CLITELIATA Tubificidae Lumbriculidae Sparganophilus ?

ACARILianoacaridae

EPHEMEROPTERA Ephemerella ignita Baetis rhodani Ecdyonurus spp

PLECOPTERALeuctra fuscaPe r1ode s mi crocephalaDinocras cephalotes

TRICHOPTI Rhyacophi Hydropsyc

TRICHOPTERA_____tila dorsalisIropsyche siltalal

Polycentropus flavomaculatus

Plectrocnemia geniculata

COLEOPTERAOrectochilus villosus

Abundance Bating

SiteTaxa Sample*

3a b

8a b

5a b

9a b

DIPTERADicranota sp 2Simuliidae 3 2Chi roncmidae 2 2 2 2Atherix sp (larvae) 1 2

TOTAL NUMBER OF TAXA 9 11 15 10 9 6 1 3

* a - 8.9.1989 b - 20.9.1989

Abundance Categories

1 - 1 individuals2 - 2 -10 3 - 11-100 4 - 101-1000

\LH\REPS90\KN16-1

APPENDIX A WATER QUALITY CRITERIA

Table A- Water quality standards for List 1 substances. (See explanatory notes)

Parameter Unit Vater quality standard Standstillprovision-

Inland Estuary Marine

Mercury Ug Hg/1 1 TAA 0.5 DAA 0.3 DAA yesCadmium ug Cd/1 5 TAA 5 DAA 2.5 DAA yesHexachlorocyclohexane Ug HCH/1 0.1 TAA 0.02 TAA 0.02 TAA yesCarbon tetrachloride Ug CC14/1 12 TAA 12 TAA 12 TAA noDi chlorodi pheny11 r i chloroethane(all 4 isomers, total DDT) Ug DDT/1 0.025 TAA 0.025 TAA 0.025 TAA yes(para, para-DDT) Ug ppDDT/1 0.01 TAA 0.01 TAA 0.01 TAA yes

Pen tachlorophenol Ug PCP/1 2 TAA 2 TAA 2 TAA yesTotal 'drins' ug/l 0.03 TAA 0.03 TAA 0.03 TAA yesAldrind ug/1 0.01 TAA 0.01 TAA 0.01 TAA yesDieldrind ug/l 0.01 TAA 0.01 TAA 0.01 TAA yesEndrin ug/1 0.005 TAA 0.005 TAA 0.005 TAA yesIsodrind ug/l 0.005 TAA 0.005 TAA 0.005 TAA yesHexachlorobenzene* Ug HCB/1 0.03 TAA 0.03 TAA 0.03 TAA yesHexachlorobutadiene* Ug HCBD/1 0.1 TAA 0.1 TAA 0.1 TAA yesChloroform* Ug CHClj/1 12 TAA 12 TAA 12 TAA no

Substances are listed In the order of publication of directives.

Standards for the following further List I substances have been proposed but not yet agreed (see Table 15): 1,2-dichloroethane (ethylene dichloride, EDC); tetrachloroethylene (perchloroethylene, PER); trichlorobenzene (all isomers, TCB); and trichloroethylene (TRI).

Key to Symbols

D - dissolved concentration, ie usually involving filtration through a 0.45-um membrane filter before analysis

T - total concentration (ie without filtration)AA - standard defined as annual average

Pootnotes

a Host directives include, in addition to the standards for inland, estuary and marine waters, a provision that the total concentration of the substance in question in sediments and/or shellfish and/or fish must not increase significantly with time (the "standstill" provision). For precise details of the wording see the individual directives and Appendix 1 of Reference 2.

b In addition to a standstill provision applying to sediments or shellfish there is a further environmental quality standard of 0.3 mg Hg/kg wet flesh "in a representative sample of fish flesh chosen as an indicator1*,

c All isomers, including lindaned The standard relating to the concentration of this substance comes into effect on 1 January 1994. e The provisions of the directive on this substance come into force on 1 January 1990.

Explanatory notes to Table a

• • • • • • • • • • • •

Table B~ Quality standards for fresh water required to support fish. (See explanatory notes)

Parameter Unit Vaters designated under d i rect i

Protection of salmonid fish

G I

the freshwater fisheries ve i s )

Protection of cyprinid f Inh

G I

Protection of freshwater life

Protection of Protection of sensitive aquatic other aquatic organisms (eg organisms (eg salmonid fish)* cyprinid fish)*

A GENERAL PHYSICO--CHEMICAL PARAMETERS

Amnonla, total ng N/l 0.031 T95 0.78 T95b 0.155 T95 0.78 T95bAmmonia* unionized mg N/l 0.004 T95c 0.021 T95c 0.004 T95c 0.021 T95c (d) (d)BOD* ng 0 2/l 3 T95 6 T95Dissolved oxygen mg 02/l >9 TAAf >9 TAA* >8 TAAh >7 TAA1pH pH unit 6 - 9 T955 ■k ' 6 - 9 T95*‘k 6 - 9 T95 6 - 9 T95Residual chlorine ng Cl2/I 0.0068 T951 0.0068 T951Suspended solids mg/1 25 TAAJ 25 TAA* ■Temperature (n> (n)

B INORGANIC ANIONS

Arsenic ■g As/1 0.05 DAA 0.05 DAA

Boron Mg B/1 2 TAA0 2 TAA0

Nitrite Rg N/l 0.003 T95 0.009 T95 [

Ph o sp h o ru s mg P/1 0.065 TAAP 0.13 TAAPSulphide ng S/1 (a ) (<1)

C METALS

See Table c

------------------------------

Table n- continued

Parameter Unit Waters designated under the freshwater fisheries di rect ive(51

Protection of salmonid Protection of cyprinid’fish fish

Protection of freshwater life

Protection of sensitive aquatic organisms (eg salmonid fish)

I

Protection of other aquatic organisms (eg cyprinid fish)

I

D ORGANIC SUBSTANCES

Hydrocarbons (r) (r)Hothproofing agents

0.001 T95*Cyfluthrin u g / 1 0.001 T95*Plucofuron Ug/1 1 T958 1 T95*PCSDs and PADs u g / 1 0.05 T95* 0.05 T95*Permethrin u g / l 0.01 T95* 0.01 T95*Sulcofuron u g / 1 25 T95« 25 T95*

Organotin compounds0.02 THA°Tributyltin u g / 1 0.02 THA®

Triphenyltin u g / 1 0.02 THA° 0.02 THA°Phenols (t) (t)

E LIST I SUBSTANCES

The EQS values listed in Table 4 for inland water apply

Explanatory notes to Table B

Host of the water quality standards in this table are defined by the European directive on the quality of fresh waters needing protection or improvement in order to support fish life(Sl. These apply only to waters designated under the directive. Derogation is allowed when designated waters undergo natural enrichment, as defined in Article 11 of the directive.Additional derogations may also be allowed as indicated in the table. Other standards, shown in the last two columns, have been set in the UK for List II substances. These apply to all fresh waters supporting aquatic life. Standards for un-ionised

ammonia and sulphide have been suggested in VRc Technical Reports (References 31 and Z8f respectively) but have not yet been adopted in the UK and are therefore very tentative. Standards for most metals depend on the hardness of the water and these are therefore shown separately in Table 8.

Key to Symbols

G - guide valueI - imperative (mandatory) value T - total concentration (ie without filtration)D - dissolved concentration ie usually involving filtration through a 0.45-um membrane filter before analysis AA - standard defined as annual average 95 - standard defined as 95-percentile HA - maximum allowable concentration

Footnotes

a In certain circumstances more stringent values nay be appropriate locally to protect especially sensitive flora or fauna (see relevant VRc Reports, References 18 to 32).

b In particular geographic or climatic conditions, and particularly in cases of low water temperature and of reduced nitrification, or where the competent authority cap prove that there are no harmful consequences for the balanced development of the fish population, a standard higher than 0.78 mg N/l may be permitted,

c This value may be exceeded for short periods during daylight hours.d A value of 0.015 TAA has been proposed (Reference 31) but not yet agreed, and is therefore very tentative, e Without inhibition of nitrification, f Minimum guide value 7 mg 02/l.g Vhen the concentration of dissolved oxygen falls below 6 mg 02/l the cause is to be investigated and appropriate measures

are to be taken (see Article 7(3) of Ref 5, which states that in the event of failure to comply with either a G or I value, the competent authority should establish whether this is the result of chance, a natural phenomenon or pollution, and adopt appropriate Measures)* The coapetent authority must also prove that the situation will have no harmful consequences for the balanced development of the fish population,

h Minimum guide value 5 u g 02/l.i Vhen the concentration of dissolved oxygen falls below 4 mg 02/l the cause is to be investigated and appropriate measures

taken, as in Footnote g, above, j Derogation is allowed in the event of exceptional meteorological or geographical conditions.k An additional footnote to Annex 1 of Ref 5 states that artificial pH variations vith respect to the unaffected values shall

not exceed ±0.5 of a pH unit within the limits falling between 6.0 and 9.0 provided that these variations do not increase the harmfulness of other substances present in the water.

Explanatory notes to Table b - continued

Explanatory notes to Table B - continued

1 This value applies at pH 6. Higher concentrations of residual chlorine can be tolerated if the pH is higher, m Thermal discharges must not cause a rise in temperature of more than 1.5 °C (although limited derogations may be allowed)

and (except under very unusual meteorological or geographical conditions) should not raise the temperature of the water above 21.5 °C or 10 °C during the breeding periods of species which need cold water for reproduction. These standards are expressed as 98-percentiles.

n Thermal discharges must not cause a rise in temperature of more than 3 ®C (although limited derogations may be allowed) and (except under very unusual meteorological or geographical conditions) should not raise the temperature of the water above 28 °C or 10 °C during the breeding periods of species which need cold water for reproduction. These standards are expressed as 98-percentiles,

o This standard comes into effect in 1990 (see Reference 2).p Indicative value (given in the 'Observations" column of Annex 1, Ref 5). A formula giving the suggested maximum load of

phosphate to a lake of average depth 18 m to 300 m is also included, viz:

L < 10 Z (1 ♦ /T)

T

where L is the load of phosphorus to the lake expressed as mg P per square metre of lake surface per year, Z is the mean depth of the lake in metres and T is the theoretical renewal time of the water of the lake in years,

q The following standards have been proposed for undissociated hydrogen sulphide (Reference 28) but not yet agreed, and are therefore very tentative. At water temperatures below 15 °C, 0.0005 mg S/1 if the concentration of dissolved oxygen is below 5 mg 02/l and 0.001 mg S/1 at higher concentrations of dissolved oxygen. At water temperatures above 15 °C,0.00025 mg S/1 if the concentration of dissolved oxygen is below 5 mg 02/l and 0.0005 mg S/1 at higher concentrations of dissolved oxygen. These standards are for the protection of salmonid and cyprinid fish. For the protection of other forms of aquatic life, in particular freshwater crustaceans, on which the values are based, a standard of 0.002 mg S/1.could be appropriate at temperatures below 15 °C, and 0.001 mg S/1 above 15 *C. All of the above standards are expressed relative to the annual average of results. During any period of 24 hours the average concentration of sulphide should not exceed 10 times the annual average.

r Petroleum products must not be present in such concentrations that they form a visible film on the surface of the water, impart a detectable taste to fish flesh or produce harmful effects in fish,

s This standard comes into effect in 1992 (see Reference 2).t Phenolic compounds must not be present in such concentrations that they adversely affect the flavour of fish

Table O- Quality itndirdi for Mtali 1b fn«ti atari raqulrtd to aiffwrl fish. (See explanatory nol»a|

t t i i n t Protection of i«i»itiv« aquatic life Protaction of other aquatic lifa

Uhlt eq salMonid fish eg cyprinid fish

T o t a l h a r d n e s s las ag C a O O j / 1 ) T o tal h a r d n e s s (as a q CeOOj/1P

0 to 50

50 to

100100 to

150

150 to

200

200 to

2 50

A b o v e

250

0 to

50

50 to

100100 to

150

150 to

200200 to

250

A b o v e

250

Chroaiiua l/gCr/1 5 D U 10 D A A 20 D A A 20 D A A 50 DAA 50 D A A 150 OAA 175 D A A 200 DAA 200 O A A 250 O A A 250 O A A

C o p p e r * (CP) |/qttl/l 5 D » 5 b 22 D95 40 D95 40 D95 40 D95 1 1 2 095° 5 D95 b 22 095 40 P95 40 D95 40 0 9 5 112 D 9 5 c

C o p p e r " <A/| pqOi/l 1 O A A ( D A A 10 D A A 10 D A A 10 D A A 28 DAA 1 DAA « D A A 10 D A A 10 D A A 10 D A A . 26 D A A

Iron*' p q ^ a / 1 1000 D M 1000 D A A 1000 D A A 1000 D A A 1000 D M 1000 O K A 1000 O A A 1000 D A A 1000 D A A 100 0 O A A 1000 O A A 1000 D A

Laad^ l/gpt>/l 4 DAA *1 10 0AAh 10 D A A h 20 D A A h 20 DAAh 20 O A A h 50 D A A 125 D A A 125 D A A 250 O A A 250 D A A 250 Q A A

N i c k e l *»g!*i/l 50 D A A 100 D A A 150 D A A 150 D A A 200 QAA 200 D A A 50 D A A 100 D A A 150 D A A 150 D A A 200 O A A 200 O A A

V a n a ^ i w * tuff/l 20 T A A 20 T A A 20 T A A 20 T A A 60 T A A 6 0 T A A . 20 T A A 20 T A A 20 T A A 20 T A A <0 T R A A 6 0 T A A

Z i n c 1 (DT) rqln/1 30 T 9 5 200 T95 300 T 9 5 300 T 9 5 300 T95 300 T 9 5 ^ 300 T 9 5 700 T 9 5 1000 T 9 5 1000 T 9 5 1000 T 9 5 1000 T9 5 *

Z i n c [AT > j«qZn/1 0 T A A 50 T A A 75 T A A 75 T A A 75 T A A 125 T A A 75 T A A 175 T A A 250 T A A 250 T A A 250 T A A 500 T A A

E i p l a n a t o r y n o t e s to T a b l e I

H o s t of tht w a ter q u a l i t y s t a n d a r d s In t h i s t able a r e U K s t a n d a r d s (Do* C i r c u l a r * * * I . O n l y for copp e r a n d sine a r a st a n d a r d s d e f i n e d In tha E u r o p e a n Fresh w a t e r Flaharias

D i r e c t i v e * . w h i c h t o w avar, a p p l y o n l y to w a t e r s d e e i q n a t e d u n d e r tha directive. But it s h o u l d ba n o t a d that th* d i r a c t l v a a n d U K s t a n d a r d s e r a alaost equivalent,

aaiMaii>9 that th* a t a t i a t i c a l d i a t r i b u t i o n of th* raaulta ia m u c h that tha 4 V p * r c m t i l a 1* a p p r o R j M t e l y four tiawa t h * a r i t h m e t i c naan. tn ca r t a i n c i c c u a a t a n c a a no r *

s t r i n g e n t v a l u e s t h a n t h o s e for t h * p r o t e c t i o n of s a l w > n i d fish n y ba a p p r o p r i a t e lo c a l l y to pr o t a c t e s p e c i a l l y a e n a i t i v * flora or fauna (a** ralavant W c rapott.

R e f e r e n c e s II to 22, 24 a n d 29).

M a t e r q u a l i t y s t a n d a r d s h a v e a l s o b e e n p r o p o s a d (or I n o r g a n i c t i n**** but Lhasa h a v * n o t y a t b a a n a d o p t e d in th* U K a n d a r a t h e r e f o r e v a r y tentative. t h a s t a n d a r d

p r o p o s a d is 25 wqS n / 1 (or t h * p r o t a c t i o n of b o t h s a n s i t i v * a q u a t i c lifa (eg s a l w o n i d fish) a n d of o thar aq u a t i c lifa ( * 9 c y p r i n i d fish) a n d is i nd*p*nd*nt of « atar

hariki*ai.I

Ra y t o S y s t o l e

T - total concMit r a t i o n fia w i t h o w t f i l t r ation)D — <U i*o lvw ) concen tration ia usually in vo lv in g f i l t r a t i o n o f th * saaplta through a 0.45-va m ilit in a f i l t a r b e fo re ana lys is ,M - s t a n d a r d d a f i n a d a s a n n u a l a v e r a g e

95 - s t a n d a r d d * f i n * d as 9 5 - p * r c * n t i l *

DP - d e s i g n a t e d fisha r i a s : w a t a r s d e s i p i a t a d u n d a r t h * F r e s h w a t e r P i s h D i r e c t i v e ^

AP - *11 w a t e r s r e q u i r e d t o s u p p o r t f i s h a n d / o r o t h a r a q u a t i c lif a

Po o t n o t * *

a friide valua. D a r09a t i o n ia s l l o w d in t h a a v ant o f n a t u r a l *nrichjaant (ia tha p r o c a s s w h e r e b y , w i t h o u t h u a t n intervention, a g i v e n

b o d y of water r *c*iv*s f r o n t h * soil c a r t a i n s u b s t a n c e s c o n t a i n a d therein), see A r t i c l e 11 of R e f e r e n c e 5.

b flia p r e s e n c e of fish in w a t e r s c o n t a i n i n g h i g h e r c o n c e n t r a t i o n s of c o p p e r n a y i n d i c a t e a p r e d o m i n a n c e of d i s s o l v e d o r g a n o - c u p r i c

c o a p l a x e s .

c B a t m a n w atar h a r & t a s s a s of 250 a n d 300 a j C i C O j / 1 t h a w a t e r q u a l i t y s t a n d a r d is 40 p q C U / 1 .

d H i q h a r c o n c e n t r a t i o n o f c o p p a r M y b a a c c e p t a b l e w h e r e tha p r e s e n c e of o r g a n i c auttar c o u l d lea d to coapl e x a t i o n .

a Tliaia s t a n d a r d s c o m * i n t o e f f e c t in 1990 <Saa R e f e r e n c e 2).

f Th» toxicity of iron incraasas as tha pH decreases, and aora strinqent standards nay be n»c»nj*ry below pH $.5.q T h e a e s t a n d a r d s ara b a s e d o n t h a t o x i c a f f a c t s of i n o r q a n i c laad; if a s i g n i f i c a n t p r o p o r t i o n of o r q a n o l e a d c o l l e g e s is prasant,

■ora s t r i n q e n t s t a n d a r d s a a y b a n e c e s s a r y -

h U h * r * b r a a d i n q p o p u l a t i o n * of r a i n b o w t r o u t a r a p r a s a n t t h a s t a n d a r d q i v a n s h o u l d ba halvad.

i I m p e r a t i v e value. D a r o t a t i o n a l l o w e d in tha a vant of n a t u r a l e n r i c h a e n t (as de f i n e d in r o o t n o t e a),

j A b o v e a w a t e r har<*ie«s of 5 0 0 aqCaOO-j/l tha w ater q u a l i t y s t a n d a r d is 500 ^ q Z n / 1 .

k A b o v a a w atar hir<lhafs of 5 0 0 • q C a C O j / I tha w a t a r q u a l i t y s t a n d a r d is 2000 v qZn/l .

Explanatory note* to Table c continued