The contamination value of a parcel of property is the amount of the market value reduction, if any, that is granted for general ad valorem property tax purposes for the assessment year because of the presence of contaminants. The contamination value for a property may be no greater than the estimated cost of implementing a reasonable response action plan or asbestos abatement plan or management program for the property. These reductions in market value include those granted by a court, by a board of review, by the assessor upon petition or request of a property owner, or by the assessor. Reductions granted by the assessor are included only if the assessor reduced the property's market value for the presence of contaminants using an appraisal method or methods that are specifically designed or intended to adjust for the valuation effects of the presence of contaminants. The contamination value for a parcel with a reduction in value of less than $10,000 is zero.