Remediation Design
Designing the fix
Remediation design translates assessment findings into a written plan specifying scope, methods, containment, worker protection, and verification criteria. The design must address the source, the reservoir, and the pathway - not just visible contamination.
Elements of a remediation design
- Scope and boundaries: what is contaminated, what is removed, what is cleaned, what is protected.
- Containment: critical barriers, negative pressure, and HEPA filtration to prevent cross-contamination.
- Work practices: removal methods appropriate to the material (e.g., minimizing dust generation), waste handling, and decontamination.
- Worker protection: respiratory and dermal protection matched to the hazard.
- Verification criteria: predefined, measurable clearance standards written before work begins.
Traps
Questions often present a design that removes visible growth but leaves the moisture source - a guaranteed failure. Another trap is a design that specifies clearance criteria after the fact, or that omits containment for a project that will disturb contaminated materials. Watch for designs that rely on chemical "kill" products without physical removal; dead growth can remain allergenic and is not a substitute for removal.
Rule of thumb
Fix the moisture first, contain the work, remove or clean the contamination, then verify against pre-written criteria. Design backwards from clearance: what must be true at the end determines what must be done.
Worked example
A design for a flooded classroom proposes replacing carpet and cleaning walls but never addresses the failed window flashing that caused the wetting. Correct design adds source repair and a drying verification step before reconstruction.