Protecting Your Assets

Nov 94

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Mar 96

Mar 95

Nov 95

James Dodds - Independent

Hydrogeologist discusses why

regular monitoring and review

o.fwater level data from .VOllr

borehole is so important.

Water level monitoring may be a condition

of your abstraction licence in which case you

should be carrying it out. However, even if it is

not a condition of your licence, you should still

monitor the level as the data collected provides

valuable information for you as the user.

A borehole water supply comprises three

principal assets, the borehole, the pumping

equipment and the water. The water supply fails

if anyone of these components fail. The amount

of water that can be pumped from a borehole is

dependent on the water level in the borehole

and how easy it is for the water to flow into the

borehole. Water levels do not remain constant.

Natural variations, the act of pumping and the

amount of recharge from rainfall all affect them.

If the water level falls too far, damage can occur

to the pump as it begins to draw in air and the

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cooling efficiency of the water is reduced.

Regular monitoring of the water level in a

borehole allows problems to be understood.

The graph above shows long term monitoring

data. Over the first three years there is a

steadily falling water level. This was due to

clogging of the screen in the borehole. The

water level reached a critical level and dropped

suddenly in March 1995. Thereafter the water

level stayed relatively constant, but had reached

the level of the pump, leading to increased wear

and tear and premature pump failure. In this

case. although water level data had been

collected, failure to plot the data as a graph and

regularly review it, meant that the problem

wasn't picked up early.

If you have a time limited licence, regular

measurement of water levels in pumping and

non pumping observation boreholes allows the

effect of pumping on the groundwater system to

be evaluated. Having this data available when

the licence is due for renewal is an important

part of demonstrating to the Environment

Agency that the abstraction is not having an

adverse environmental impact. This could be

vital evidence if it is necessary to prove your

case for renewal.

Monitoring cannot be carried out retrospectively

and the longer the record period the more

confidence you will have in the interpretations.

If you are not monitoring you should start now

and take a measurement every 20 to 30 days.

Keep the data in a book or on a spreadsheet and

plot it as a graph as you collect it.

Regular monitoring, recording data properly and

presenting the results as an appropriate graph

helps you protect the assets that provide you

with the water that is so important to your home

or business. WB & AD Morgan Ltd can provide

you with help and advice on setting up and

maintaining a monitoring system and with the

aid of our expert hydrogeologists can provide

interpretation and reporting on the results for

you to present to the Environment Agency.