§ 13.12.220. Best management practices for controlling discharges of silver process wastewater to the city's sewerage system.

The city of Salisbury establishes the implementation of the Code of Management Practices for Silver Dischargers providing for best management practices for controlling discharges of silver process wastewater to the city's sewer system.

A.

Purpose. The purpose of this section is to prevent the metal silver, designated as a toxic pollutant by the United States Environmental Protection Agency (USEPA), from being discharged to the sewer system without treatment. This section requires facilities performing processing of photographic materials to install and maintain pretreatment equipment that is designed to achieve a level of treatment appropriate to the size of the facility. Unlike other metals reduction strategies, this silver control regulation does not require facilities to attain specific numerical limits, but rather to incorporate the strategy of best management practices.

B.

Definitions. For the purpose of this section:

1.

"Best management practices (BMPs)" are typically a schedule of activities, prohibitions, maintenance policies and other management procedures that are implemented to prevent or reduce the discharge of pollutants into the public sewer system. BMPs also include pretreatment requirements, pretreatment equipment installation, operating procedures and practices to control plant site runoff, spillage or leaks, sludge or waste disposal or drainage from raw material storage.

2.

"Best management practices plan (BMPP)" is an operational methodology using BMPs to prevent and/or reduce the discharge of silver to the city sewer system.

3.

"Total silver process wastewater" means the sum of all aqueous solutions used in silver imaging processes, including photography film developers, fixers, bleach-fix, stabilizers, low-flow washes, rinse waters, other washes and all similar solutions.

4.

"Silver-rich solutions" include fixers, bleach-fixes, stabilizers (e.g., plumpness stabilizers and chemical washes), low-flow washes and all functionally similar solutions.

5.

"Silver test paper" means test paper coated with an analytical reagent which reacts by changing color in relationship to the amount of silver in solution. A reference color code allows users to determine the approximate amounts of silver in solution.

C.

1.

Best management practices plan for dischargers of total silver process wastewater from photographic processing facilities to the city's sewer system:

a.

All pretreatment processes installed pursuant to these regulations shall achieve at least the minimum percent recovery of silver-rich solutions required by the applicable subsection of this regulation.

b.

In lieu of complying with any requirements of this BMPP, persons discharging total silver process wastewater to the public sewer system may have all silver-rich solutions transported off-site for recovery, reclamation and/or refinement by a certified hazardous waste hauler. Persons that exercise this option are required to manifest and/or document all loads regarding the disposal of silver-rich solutions, including the name of transporter, the quantity removed and how the silver-rich solutions are disposed.

c.

All records and measurements kept pursuant with this BMPP shall be recorded in a silver recovery log and be available at all times for inspection.

d.

Persons identified as significant industrial users must obtain an industrial wastewater discharge permit developed on a case-by-case basis.

e.

Persons identified as a photographic processing facility must obtain a special permit based on best management practices.

f.

Design of pretreatment processes shall be based upon percent recovery of silver-rich solutions.

g.

On or before March 1, 1998, any person that discharges total silver process wastewater to the public sewer system shall prepare and implement this best management practices plan. BMPP shall include the following:

i.

The facility must have a spill plan to ensure spills of silver-rich solutions are not accidentally released to the publicly owned treatment works (POTW).

ii.

All photographic processors shall maintain their processing and holding tanks for silver-rich solutions and the silver recovery and/or management system in a manner that protects the materials from accidental release to the POTW.

iii.

All photographic processors shall install taps on the influent and effluent of their silver recovery units to provide access for representative monitoring of the efficiency of their pretreatment process.

2.

Dischargers of less than two gallons per day silver-rich solutions and/or less than one thousand (1,000) gallons per day of total silver process wastewater shall:

a.

Install, operate and maintain one of the following technologies designed to recover a minimum of ninety (90) percent of the silver from silver-rich solutions:

i.

Metallic replacement unit(s) in series and operated simultaneously,

ii.

Electrolytic recovery, or

iii.

Chemical precipitation;

b.

Install taps on influent and effluent of silver recovery units to provide access to representative samples for monitoring the efficiency of the pretreatment process;

c.

Test for silver concentration in the influent and effluent from the silver recovery units using silver test paper and/or test kits once per week on a day that is representative of normal operations;

d.

Collect one composite sample of the influent and effluent of the silver pretreatment system once every twelve (12) months on a representative day. This sample shall be analyzed for total silver using the Maryland Department of the Environment Water Management Administration Toxic Substance Analytical Protocol and 40 CFR Part 136 sampling and preservation methods by an approved laboratory. Results shall be mailed to the city's pretreatment office;

e.

Keep written records of the measurements required by this BMPP in a silver recovery log book at their facility for a minimum of three years.

3.

Dischargers of two to twenty (20) gallons per day silver-rich solutions and/or one thousand (1,000) to ten thousand (10,000) gallons per day of total silver process wastewater shall:

a.

Install, operate and maintain one of the following technologies designed to recover a minimum ninety-five (95) percent silver from the silver-rich solutions:

i.

Electrolytic recovery and metal replacement,

ii.

Chemical precipitation, or

iii.

Any combination of the above;

b.

Install taps on influent and effluent of silver recovery units to provide access to representative samples for monitoring the efficiency of the pretreatment process;

c.

Test for silver concentration in the influent and effluent from the silver recovery units using silver test paper and/or test kits once per week on a day that is representative of normal operations;

d.

Collect one composite sample of the influent and effluent of the silver pretreatment system once every six months on a representative day. This sample shall be analyzed for total silver using the Maryland Department of the Environment Water Management Administration Toxic Substance Analytical Protocol and 40 CFR Part 136 sampling and preservation methods by an approved laboratory. Results shall be mailed to the city's pretreatment office;

e.

Measure and record quantities of total silver process wastewater discharged to the public sewer system;

f.

Keep written records of the measurements required by this BMPP in a silver recovery log book at their facility for a minimum of three years.

4.

Discharges of over twenty (20) gallons per day of silver-rich solutions and/or over ten thousand (10,000) gallons per day total silver process wastewater shall:

a.

Install, operate and maintain one of the following technologies designed to recover a minimum ninety-nine (99) percent silver from the silver-rich solutions:

i.

Two metallic replacement units installed in series and operated simultaneously and one electrolytic recovery unit, or

ii.

One electrolytic recovery unit and chemical precipitation;

b.

Install taps on influent and effluent of silver recovery units to provide access to representative samples for monitoring the efficiency of the pretreatment process;

c.

Test for silver concentration in the influent and effluent from the silver recovery units using silver test paper and/or test kits once per week on a day that is representative of normal operations;

d.

Collect one composite sample of the influent and effluent of the silver pretreatment system once every three months on a representative day. This sample shall be analyzed for total silver using the Maryland Department of the Environment Water Management Administration Toxic Substance Analytical Protocol and 40 CFR Part 136 sampling and preservation methods by an approved laboratory. Results shall be mailed to the city's pretreatment office;

e.

Measure and record daily quantities of total silver process wastewater discharged to the public sewer system;

f.

Keep written records and measurements at their facility for a minimum of three years;

g.

If the facility consistently maintains its percent recovery for two years, the frequency for the collection of the composite sample of the influent and the effluent may be reduced, at the city's discretion on a case-by-case basis.

D.

Implementation Effect. This section is in addition to any requirements presently established or as may be established from time to time by ordinance, resolution or policy of the city council of the city, department of water works or other offices, boards, commissions, agencies, divisions or departments of the city and all other sections of this chapter are in full force and effect, regardless of the numbering of this section or location in the chapter.

(Ord. 1983 (part), 2006)

( Ord. No. 2454, 10-9-2017 )