SOURCE

NATURE

 TIME FRAME

DETAILS

Coal Gas Retorts (Ammoniacal Liquor)

Became Clarification Water

Entire History

Expect evidence of operational-era leakage at each gas-plant production component and along each pipe flow path from retort to gas holder

Quench Water at
Coal-Gas Coke and
By-Product Coke-
Ovens

Cool, Clear Water Sprayed at Retort Floor or on hot coke car

Entire History

Collected in a floor channel against the retort bench front on the retort house floor, then channeled to the plant sewer for subsequent real- time discharge.  At coke ovens, originally sent to waste lagoon or discharged to open drainage; after ca. 1920 to cooling ponds, for re-use.

Clarification Waters
(At all Components, Condenser to Purifiers)

Required Cool and Reasonably Clear Water to Drop Tar

Entire History

Made up of waters of condensation released with the gas at all types of gas machines then carried to and through the clarification process. After ca.1890, some plants had quasi-separate systems in which clear, cool water would be added at individual clarification devices, all to enhance removal of tar, ammonia, and other detrimental residuals. Ultimate fate was discharge to the plant sewer or to the ground, as an option of plant management.

Clarification Device Sumps
  - Condenser
  - Washer
  - Scrubber
  - Washer-Scrubber

Used Make-up Water

Began with  condenser use
 ca. 1812.
 Others after ca. 1890

Sumps became design features to collect tar (PAH) globules and particles and to pass the remainder of the condensation effluent. Sumps were hand-cleaned or pumped and tar managed in accordance with plant directive.  The portion of the collected residuals represented by tar sludges generally was considered waste.

Carburetted Water Gas
  (Gas Liquor)
Tar-Water Emulsions

Reached as High as 90% of
CWG Tar

Began about 1910

Emulsions came from undesirable use of heavy or crude oil and bituminous coal, in contravention to conventional wisdom but in response to market conditions of the time.  Dumping to the ground was common at gas works where evidence of dehydration equipment is not found today. Usually found as disposed to tar “ponds” or “lagoons.”

Purifier-Box Gas Liquor Collection and Overflow

Constant Release of Collected Moisture

Always Present

Gravity collection in box bottoms and drained to discharge in accordance with plant directives.
Today, most purifier-box locations are hotspots on this account.

Gas Holder Water-Seal
Leakage

Constant Flow Through Walls of Subsurface Tanks (where present)

Always Present in Pit-Type Holders

Operational-era outward leakage of light and medium oils from pit-type gas holders, through rendering, bricks, puddle and dumplings, and into surrounding soil, and contact with ground water, where present.

Tar Separators
(Underground Types)

- Wooden Construction

- Concrete

Common

Less Common

General use began about 1890

Operational-era outward leakage of gas liquor minus what tar globules were separated and retained. Effluent still carried MAH/DAH/PAH as TDS and microparticles.

“Sediment” Basins

Sprayed Effluent

1920s

In response to recommendations of AGA Committee on Gas House Wastes (1920s).

Gas Liquor Centrifuges

Dewatering of Tar-Water Emulsions

1929

Koppers Corp., in response to equipment recommendations of AGA Committee on Gas House Wastes.

Lampblack
Utilization

Dewatering

ca. 1910

Corps of Engineers restriction on dumping of lamp black into Willamette River at Portland, OR (1906) led to creation of lampblack recovery and conversion to fuel briquettes. Many other plants continued to dump this waste, often containing PAHs.

Gasyard Drips

As Leaks

ca. 1840

Collected light-oil and the condensates along gasyard and distribution lines;  Prone to leak to environment during the operational life of the gas works.

Benzol Plants at
By-Product Ovens and
MGP Plants

Prepared Raw Benzol

From 1914

Benzol used as "motor spirits" for vehicle fuel.  Major British and U.S. program in WWI for munitions recovery of toluene as a benzol constituent Processing collected and released effluent waters.