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Photo Processing Operations


Typical substances utilized in photo processing include fixer, bleach fixer, developers, stabilizers, and rinse water. Due to the chemical constituents in these substances (used and unused), discharge of these substances to the sewer is typically prohibited. For example, used fixer typically contains levels of silver which exceed the Washington Suburban Sanitary Commission's (WSSC) limitation of 2 parts per million (ppm). As a result, discharge of used fixer to the sewer is a violation of WSSC regulations. In these cases, treatment and recovery equipment can be installed and operated to extract silver from the used fixer to allowable levels below 1.2 ppm.

This fact sheet provides University of Maryland personnel engaged in photo processing operations (including X-ray) with wastewater discharge best management practices (BMPs). The BMPs are designed to promote pollution prevention and ensure effective treatment and management of photo processing wastes prior to discharge. As a discharger of wastewater associated with photo processing operations, adhering to these BMPs will help to ensure your operation is managed in an environmentally safe and responsible manner and promotes compliance with applicable WSSC regulations. (1)

Applicable University Policy

University of Maryland Hazardous and Regulated Waste Procedures Manual.

Applicable Regulation

The Plumbing and Gas Fitting Regulation - WSSC

Summary of Requirements

The following provides a summary of best management practices associated with photo processing operations.

  1. Silver Bearing Wastes - Silver bearing wastes include, but are not limited to, fixer, bleach-fix, stabilizers and functionally similar solutions. Due to silver content, these wastes typically exceed WSSC's maximum daily limit for the discharge of silver (1.2 ppm). Normally a pre-treatment system is utilized to treat these substances so that silver levels are below WSSC limitations. Typically these silver bearing wastes are discharged through a properly sized, designed, installed, operated, maintained and serviced silver recovery unit prior to discharge to the sewer. These units extract silver from the material through physical or chemical methods.

    The silver recovery equipment must be operated and maintained in accordance with manufacturer's specifications. The facility should maintain the manufacturer's specifications for its silver recovery equipment with the equipment. In addition, it is recommended that the facility maintain a silver recovery management log which records all maintenance and silver recovery activity. The Department of Environmental Safety, Sustainability and Risk (ESSR) is available for assistance with these recommendations.


  2. Prohibited Wastes and Local Limits - In addition to silver discharge limits, the facility must comply with WSSC Regulations on Prohibited Discharges. These regulations list specific waste and materials which are prohibited from being discharged to the WSSC sewer system including, but not limited to, oils, solvents (i.e., xylene, toluene, benzene, MEK), high temperature liquids and vapors (greater than 150 °F), mercury, PCBs and various pesticides. Hazardous waste is strictly prohibited from being discharged to the sewer. Refer to "Wastewater Practices" Fact Sheet for additional information and/or contact ESSR for assistance.


  3. Signs - As a reminder to personnel involved with or in the vicinity of photo processing operations, signs should be posted at nearby sinks indicating that untreated discharge of chemicals is strictly prohibited.


Employee Training: It is recommended that individuals involved in photo processing operations be trained in the operation and maintenance of silver recovery equipment, spill procedures and with applicable WSSC requirements. Contact ESSR for training assistance. Maintaining a training record/log, which records personnel that have been trained, is a recommended practice.


All areas that discharge to the WSSC sewer system are subject to certain notification requirements. It is recommended that these notifications be made by ESSR.


Weekly Inspections: Weekly visual inspections of silver recovery equipment will help to ensure that the equipment is operating properly and that operational problems will be addressed in an expedited manner.

Preventive Maintenance: The silver recovery system should be maintained and serviced in accordance with manufacturer's recommendations. See your service vendor for details.


It is recommended that facilities conducting photo processing operations maintain the following records:

  • weekly inspection records;
  • silver recovery management documentation (i.e., manifests, bills of lading, cartridge management replacement records, etc.);
  • employee training records; and
  • manufacturer's specifications for photo processing equipment and treatment systems.


Written Program

A written program is not required. See Recordkeeping section.

University Resources

Department of Environmental Safety, Sustainability and Risk (301) 405-3960
ESSR Fax No.    (301) 314-9294
ESSR Website:
Hazardous and Regulated Waste Procedures Manual
UMD Waste Disposal Guidelines Calendar

Written 5/98
Revised 4/01
Reviewed 4/05

(1)WSSC regulates all wastewater discharges in the WSSC Sewerage District. The University of Maryland is located within the WSSC Sewerage District and is subject to WSSC regulations for the use of the sanitary sewer system.