| SUMMARY OF GOOD PRACTICE - WATER |
| Good Practice for Mineral Planning Authorities |
Be aware of the Environment Agency?s policies when drawing up the Minerals Local Plans, which will be important in assessing applications.
After close consultation with the Environment Agency, consider the need to agree or
specify planning conditions relating to:
- delaying operations until monitoring data are available to demonstrate
the absence of problems or allow precautionary measures to be agreed;
- nature, area and depth of working;
- arrangements for recharge;
- means to minimise problems from storage of oil/chemicals;
- monitoring of quantity and quality of discharge from site which must be covered by a licence from the Environment Agency;
- siting and landscaping of flow-balancing reservoirs;
- siting of settlement lagoons and disposal of silt;
- provision of hard standing and bunding of storage/process areas;
- diversion of water courses;
- provision of monitoring.
Consider the need to seek agreements regarding:
- monitoring off-site, e.g. of groundwater levels and abstractions;
- pre-condition surveys for householders who may be concerned by de-watering causing shrink damage;
- compensatory measures, e.g. for abstractions likely to be adversely affected.
An MPA can face prosecution from English Nature if it fails to take action within its influence to protect a SSSI from harm
which may be caused by de-watering.
|
| Good Practice for Operators |
Consult the Environment Agency about possible groundwater issues,
any alterations to existing surface water courses,
nearby river corridors and any fixed discharges.
Consider the need to undertake a comprehensive baseline survey which should start at least two years before
commencement of operations.
Establish a detailed monitoring system where
necessary.
Carry out pump tests if appropriate.
Monitor during operations:
- ground water levels;
- neighbouring abstractions;
- quantity and quality of water being discharged;
- quantity and quality of recharge flows;
- neighbouring land, crops and ecology for problems.
Plan to minimise potential problems as well as to meet Environment Agency or MPA
conditions.
Consider not dewatering or, if unavoidable, dewatering progressively in
cells and reducing the inflow of water by sealing.
Leave effective filter layers between aquifers.
Use codes of practice for temporary spoil mounds and slope stability,
provide for recharge of aquifers.
Provide impervious bases and bunding for oil/chemical stores and wet-process plant.
Avoiding seepage of contaminated run-off through floor of quarry.
Provide bunding to keep surface water out of workings.
Design water system, including dewatering flows, in an integrated
way covering:
- flow balancing by sumps and pumping;
- quality control by settlement in sumps and lagoons, pH balancing;
- oil and scum removal;
- use of water in processing plant and treatment of effluent;
- containment of spillage from storage and processing areas;
- use of water in dust control (may need abstraction licence even if
resulting from dewatering);
- use of clean water to counteract groundwater lowering, e.g. in nearby pools;
- regular cleaning and maintenance of water system.
Limit erosion by:
- vegetating, physically protecting or
roughening the surfaces of overburden, soil or waste mounds;
- progressively restoring working areas;
- lining water courses.
Design sumps and lagoons to cope with all conditions, including
agreed or specified storm return period, by ensuring that:
- they are big enough;
- scouring is avoided;
- the retention time is adequate, if necessary, enhancing settlement
by use of agreed flocculants or mechanical means.
Use progressive working so that previously excavated areas
can serve as
lagoons.
Leave margins around water courses, river corridors and other sensitive areas.
Minimise obstruction of flood regime by mounds of overburden or waste.
|
|
|