a) Maintain records. Each registrant shall maintain records showing compliance with this Part for five years. Records may be stored in electronic media with the capability to produce legible, accurate, and complete records during the required retention period. Records such as letters, drawings, and specifications shall include all pertinent information such as stamps, initials, and signatures.

1. 1) Each registrant with a combined radium concentration greater than 3.1 pCi/g (dry weight basis) shall maintain records of the following:

   1. A) Registrants who dispose of water treatment residuals in an IEPA-permitted municipal solid waste landfill or a facility authorized to dispose of that material in accordance with any federal or State solid or hazardous waste laws:

      1. i) Quantity of water treatment residuals disposed of;
      2. ii) Concentration of combined radium in pCi/g (dry weight basis) contained in the water treatment residuals;
      3. iii) Dates the water treatment residuals were disposed of in a landfill;
      4. iv) Name and location of the landfill receiving the water treatment residuals; and
      5. v) Any additional records showing compliance with this Part requested by the Agency.

   2. B) Registrants who land apply water treatment residuals:

      1. i) Tax parcel identification number of lands utilized for application of water treatment residuals;
      2. ii) County, township, section, and range in which the tax parcel lies;

   3. iii) Tillable acres for the tax parcel;

      1. iv) A signed landowner acknowledgement form for the tax parcel;
      2. v) Total dry tons of water treatment residuals applied to the tax parcel;
      3. vi) For each application, the concentration of radium-226 and radium-228 in pCi/g (dry weight basis) contained in the water treatment residuals;

   4. vii) Dates the water treatment residuals were land applied;

      1. viii) The cumulative increase and total combined radium concentration in the soil for each tax parcel having received application of water treatment residuals; and
      2. ix) Any additional records showing compliance with this Part requested by the Agency.
2. 2) Registrants identified in Section 622.40 who dispose of residuals via release into sanitary sewerage shall maintain documentation demonstrating that the total quantity of material released in a year does not exceed 1.0 Ci.
3. 3) Registrants who dispose or repurpose water treatment residuals approved by the Agency under 32 Ill. Adm. Code 340.1020 shall maintain documentation in accordance with this Section.
4. 4) All Registrants shall maintain documentation pertaining to radon measurements.