Groundwater protection is a core task on construction sites, in concrete demolition and special deconstruction, in rock excavation and tunnel construction, as well as in natural stone extraction. The aim is to prevent the introduction of pollutants, avoid impairing the water balance, and preserve the natural filter function of the subsoil. In this knowledge section by Darda GmbH, fundamentals, risks, and practical, hands-on measures are described that support the protection of groundwater when working with concrete demolition shears, rock and concrete splitting devices, hydraulic power packs, and cutting and shearing tools.
Definition: What is meant by groundwater protection
By groundwater protection we mean all planning, technical, and organizational measures that prevent groundwater from being adversely affected by human activities. These include avoiding pollutant inputs (e.g., oils, concrete slurries, metals), limiting changes to flow paths in the subsoil, as well as the controlled discharge, treatment, and reuse of water that arises. The protection approach is preventive: avoid inputs rather than remediate later.
Groundwater protection in concrete demolition, rock excavation, and tunnel construction
In construction and deconstruction projects, mineral construction materials, operating supplies, and water streams encounter sensitive subsoil. In concrete demolition and special deconstruction, during strip-out and cutting, in rock excavation and tunnel construction, as well as in special operations (e.g., tank dismantling), risks to groundwater arise. Methods with controlled energy input—such as the use of concrete demolition shears or rock and concrete splitting devices—reduce vibrations, decrease secondary water demand, and limit uncontrolled crack formation, which lowers the risk of creating new infiltration pathways.
Typical hazards to groundwater on demolition and construction sites
Hazards rarely arise from a single source, but from the interaction of multiple factors. The following points are particularly relevant in practice:
- Operating fluids from hydraulic power packs (e.g., hydraulic oil): leaks can cause localized inputs. Sealed surfaces, drip trays, and regular leak-tightness checks are essential.
- Concrete wash water and cement slurry: high pH values and fine particles can impair groundwater. Settling, filtering, and pH control are necessary.
- Cutting and cooling water: suspensions generated during wet cutting must be recirculated and treated instead of infiltrating.
- Contaminated components: when deconstructing installations where hazardous substances were used, sealing, decontamination, and separate capture are crucial.
- Metal abrasion and rust particles: when using steel shears, combination shears, and multi cutters, fine abrasion is produced that must not enter the subsoil.
- Tank dismantling: when opening tanks (e.g., with tank cutters), residual contents, condensates, and wash waters must be consistently retained and disposed of.
- Hydrogeological changes: strong vibrations or uncontrolled blast-induced fractures can create new preferential flow paths.
Low-emission methods: hydraulic splitting and selective crushing
Hydraulic methods such as rock and concrete splitting devices and rock splitting cylinders act with controlled, locally confined force. Likewise, concrete demolition shears and multi cutters enable selective size reduction of components. These working methods reduce secondary emissions, limit the spread of fine dust, and minimize the need for flushing or cooling water. This is advantageous for groundwater protection because fewer suspensions are generated and the subsoil is hydrogeologically spared.
Advantages with regard to protecting the subsoil
- Lower vibrations: reduced risk of widening existing fractures or creating new crack systems.
- Reduced water demand: less flushing water lowers the treatment volume and the risk of infiltration.
- Defined fracture lines: better control of demolition edges, reduced release of fine particles.
- Selective material removal: clean separation of construction materials facilitates orderly disposal.
Water management, sealing, and site setup
Effective groundwater protection begins with site setup. Areas are sealed, water pathways are defined, and emergency materials are kept ready. A closed water management approach is important—from generation through treatment to orderly discharge.
- Seal and contain: equip work areas with liquid-tight underlays, create edges, secure inlets.
- Capture and treat: set up settling basins, filtration stages (sedimentation and, if necessary, filtration), and pH control for concrete suspensions.
- Closed-loop circulation: return cutting and cooling water in closed systems; minimize fresh water demand.
- Separation of streams: strictly separate clean stormwater from contaminated process waters.
- Emergency preparedness: keep absorbents, sealing cushions, and collection containers close at hand; define reporting pathways.
- Regular inspections: periodically check and document sealed surfaces, hose connections, and units.
Planning, permitting, and preventive measures
Before starting work, the hydrogeological framework conditions must be examined: soil structure, depth to groundwater, protected areas, and discharge options. Measures and treatment capacities are summarized in a protection concept. Requirements can vary regionally; it is advisable to coordinate these with the competent authorities at an early stage and to take a conservative approach.
Strip-out and cutting: dust, water, and pH
In strip-out and cutting work, a balance between dust suppression and water generation is required. Concrete demolition shears often enable low-dust and low-water operation. Where wet cutting is necessary, a closed-loop system with sedimentation and filtration is recommended. Handling concrete wash water requires pH monitoring; discharges without treatment should be avoided.
Operate hydraulic power packs safely
- Drip trays under couplings and units, drip protection on connections.
- Leak monitoring (visual inspection, absorbent indicator mats), immediate action in the event of dripping.
- Proper storage of operating supplies; refueling and coupling changes only on sealed surfaces.
- Keep absorbents and tightly sealing collection containers ready for contaminated material.
Special situations: tank dismantling and special operations
When dismantling tanks and pipelines, tank cutters, steel shears, and combination shears are typical tools. Residual contents are recorded in advance, vapors are controlled, and wash waters are treated in closed systems. Cutting and flushing media must not infiltrate. Abrasion and chips must be captured and recorded as waste. In special operations, pay heightened attention to sealing, emergency equipment, and documented clearance measurements.
Natural stone extraction and groundwater
In natural stone extraction, preserving fracture networks and separating surface runoff from process water is central. Hydraulic splitting with rock splitting cylinders limits vibrations and unwanted crack formation. Settling basins, reed or filter shafts for fine particles, and clearly defined traffic routes prevent suspensions from reaching the subsoil.
Monitoring, documentation, and training
Effective groundwater protection is measurable. Monitoring pH, conductivity, and turbidity at defined points supports the control of measures. Logbooks for hydraulic power packs, test records for sealed surfaces, and staff training foster routine and confidence in action. Deviations are recorded and corrected.
Practical guide: measures package for projects
- Site analysis: clarify hydrogeology, protection levels, flow paths, and discharges.
- Protection concept: define sealing, water management, emergency management, and responsibilities.
- Select suitable methods: where possible, use concrete demolition shears and rock and concrete splitting devices to limit water and dust generation.
- Water management: size closed-loop systems, settling and filtration stages; organize pH monitoring.
- Material flow management: separately capture slurries, abrasion, and residuals; use labeled, tight containers.
- Regular monitoring: define measuring points, frequencies, limits, and trigger values.
- Final inspection: clean areas, check seals, complete records.
- Follow-up: for longer projects, perform periodic checks and adjustments.
Material and waste management in deconstruction
Clean material streams are a key component of groundwater protection. Mineral fractions are captured separately from potentially contaminated materials. Equipment is cleaned on sealed areas, and cleaning water is collected and treated. For concrete wash water, controlled neutralization and solids separation are required; uncontrolled infiltration must be avoided.
Special notes on concrete wash water
- High pH value requires monitoring and appropriate treatment before any possible discharge.
- Retain solids through sedimentation/filtration; dispose of residues properly.
- Only discharge treated waters within the applicable requirements; when in doubt, act conservatively.