You will learn
Go and look
Everything so far has happened at a desk. Now you go and see the site with your own eyes. The walkover checks your research, fills the gaps, and often finds things no record shows.
- Plan a walkover from your desk findings, including permission, timing and equipment.
- Carry it out safely, and know when to stop.
- Record what you see so that someone else can check it later, and compare it with your desk findings.
Why it matters
What only the site can tell you
Records tell you what might be there. The site tells you what is there today. Some things simply do not appear on any map or database:
Fresh clues
Stained ground, a fuel smell, dead patches of grass, dumped waste, a vent pipe sticking out of the ground.
Water
Soft, wet ground, springs, standing water and drains that no plan shows.
Nature
Japanese knotweed, nesting birds, an old building that could hold bats.
Access
How wide the gate is, whether a drilling rig can get in, low overhead lines, livestock in the field.
Neighbours
Cracks in nearby walls, a works next door, people who remember the site’s past.
Change
New tipping, demolition or building since the latest aerial image.
The idea, in plain words
Plan before you go
Never enter land without the owner’s permission. On operational sites, such as treatment works or factories, you may need a site induction, a permit or an escort. Arrange it in advance.
List every possible hazard and constraint from Lessons 3 to 5, and what you want to confirm on site. For example: “Find the former tank area. Look for the filled-in pond. Check the river bank for knotweed.”
Be clear what “the site” means: just the yard, or the access road and the land around it too? Mark where you expect each feature to be.
Daylight, and safe weather. Note the season and recent weather, because they change what you see. Ground that is firm in a dry summer may be soft after rain.
Your plan and checklist, a phone or camera, a notebook, a tape measure, something to give scale in photos, and the right protective clothing: boots, high-visibility clothing and gloves. Charge your phone.
The idea, in plain words
Stay safe
A walkover looks easy, but old sites can be dangerous. Follow your organisation’s safety procedures, and keep to these basics:
Tell someone where you are going and when you will be back, or go with a colleague.
Never enter manholes, tanks, chambers or other confined spaces, or unsafe buildings.
Leave stained soil, drums, needles and broken cement sheets alone. Some old sheeting contains asbestos. Wash your hands before eating.
Open shafts and holes, rotten covers, soft ground, river banks, deep water and sharp rubble.
Overhead power lines, moving vehicles on operational sites, and livestock in fields.
No observation is worth an injury. Leave, record why, and say in the report what you could not see.
The idea, in plain words
What to look for
Walk the whole site, including the boundaries, and look over the fence at the neighbours. Work through your checklist, but keep your eyes open for the unexpected.
| Look at | Clues to note |
|---|---|
| Ground and slopes | Hollows, mounds, cracks, steps in the ground, soft or wet areas, signs of slipping |
| Water | Springs, ponds, ditches, standing water, flood debris on fences |
| Past uses | Slabs, foundations, old walls, rail lines, vent pipes and fill points from tanks |
| Contamination | Staining, odours, ash and clinker, drums, dead or unusual vegetation, possible asbestos sheeting |
| Nature | Japanese knotweed and other invasive plants, nests, buildings and trees that could hold bats |
| Services | Manhole covers, valve covers, marker posts, poles and overhead lines |
| Neighbours | What is next door, cracks in nearby buildings, anything that could affect the site |
| Access | Gate width, headroom, firm ground for a rig, vegetation that would need clearing, livestock |
The idea, in plain words
Record it so others can check it
- Photographs: number every photo and note where it was taken from and which way you were facing. Include a scale, such as a tape or a ranging pole.
- Sketch plan: mark what you saw and where each photo was taken.
- Notes: work through your checklist, ticking what you confirmed and noting what you found that was new.
- People: if a site manager, neighbour or former worker tells you something useful, write it down with their role, not their name, and the date.
- Conditions: the date, the weather, recent weather, and anything you could not reach or see.
When the records are missing
In many places, old maps and databases are thin or do not exist. Then the walkover and the people who know the area carry more weight. Ask how long the land has been used this way, what was there before, whether it floods, and whether anything has ever been buried or dumped. Then say clearly in the report which findings come from records, which from observation, and which from people.
Photos you can check later
Months later, someone will ask “where exactly was that?” Photos with a number, a location, a direction and a scale answer the question. Photos without them are pictures, not records.
Recommend a visit before the rigs arrive
Your walkover may be months before the investigation. Recommend that the investigation contractor visits the site before mobilising, to check access and ground conditions at each planned location. It avoids paying for machines that arrive and cannot reach the holes.
On our site
Walking Brindlemere Yard
Here is our walkover section. Notice the last column: every observation is compared with the desk findings.
Brindlemere Yard: Desk Study Report (fictional example)
6. Site walkover
The site was walked by the author on a weekday in March, in overcast weather, after a week of rain. Access was arranged with the landowner. All parts of the site were reached except the steep river bank, which was viewed from the top.
| Observation | Photo | Compared with desk study |
|---|---|---|
| Concrete slabs and rubble mounds across the centre | 1 to 4 | Confirms the demolished works |
| Vent pipe and capped fill point near the northern boundary | 5 | Confirms the former tank area |
| Black staining on the slab near the vent pipe; faint fuel odour | 6 | Supports possible fuel contamination |
| Hollow with reeds and standing water in the south-east corner; ground soft underfoot | 7 | Consistent with the filled-in pond |
| Ash and clinker along the western edge | 8 | Confirms the former railway sidings |
| Japanese knotweed along the river bank, about 10 m by 5 m | 9 | New finding |
| Old brick manhole with a pipe running towards the river | 10 | New finding: an unrecorded old drain, a possible route to the river |
| Overhead line along the western boundary, low over the side gate | 11 | Confirms the records; the side gate is not suitable for a rig |
| Main gate 3.5 m wide; slabs firm, ground near the river soft after rain | 12 | Access for a rig through the main gate; avoid the riverside in wet weather |
Information from people. A neighbour who worked at the engineering works said it had a metal plating shop in the north-east corner. This is not shown on any map. It is a possible source of metal contamination.
Notice the plating shop
No record mentioned it. One conversation over the fence added a new possible source of contamination. That is why you talk to people, and why you write down where each piece of information came from.
Your turn
Plan, walk and record
Task (planning 15 minutes, plus your visit)
- Write a walkover checklist for your site from your answers to Lessons 3 to 5.
- Only if it is safe and you have permission, or the site is fully visible from a public place: walk or view it, and take numbered photos.
- Fill in a table like ours: Observation, Photo, Compared with desk study.
If you cannot visit, use street-level imagery and recent aerial photos instead, and say so clearly. That is a limitation, and good reports state their limitations.
Quick check
Five quick questions
This is not a test. It simply shows you whether you are ready for Lesson 7. Choose an answer to see the explanation.
Key points
What to take away
- The walkover checks your desk findings and finds what no record shows.
- Plan it from your desk findings: permission, a checklist, a plan with the boundary, timing and kit.
- Stay safe: never enter confined spaces or unsafe buildings, do not touch suspect materials, and stop if it feels wrong.
- Record it so others can check it: numbered photos with location, direction and scale, a sketch plan, and the conditions on the day.
- Talk to people, record their role and the date, and say where each piece of information came from.
- Recommend that the investigation contractor checks access before mobilising.
Up next: Lesson 7
Making sense of it. Bringing everything together into a conceptual site model, and ranking the risks.