Robins AFB Industrial Wastewater Treatment Plant 3 (IWTP3) treats four wastewater streams from their metal plating facility-chrome, cyanide, acid/alkali, and chelate. The four streams undergo various pretreatment prior to combining and going through final microfiltration process and then discharge. IWTP3 is currently not in operation due to problems with UV oxidation system and the microfiltration system. Flow is currently being directed to IWTP2 for treatment. Robins desired to replace UV oxidation and microfiltration with alternate processes, make other miscellaneous improvements and put IWTP3 back into operation to facilitate direct discharges to the Ocmulgee River.
As requested, the scope of our services included collecting wastewater samples from four existing samplers and analyzing the water samples for various parameters. The results of the sampling and will be used for future design criteria.

The tasks included the following:
• Calibration, Certification and Programing of Existing Samplers
• Wastewater Stream Sampling (Phase 1A Representative Sampling [First 60 days and Phase 2A Representative Sampling] [Second 60 days])

Sampling was conducted during the five-day work week and consisted of daily in-situ field measurement readings for pH, temperature, oxidation reduction potential (ORP), and conductivity using a Horiba™ multi-parameter water quality meter from each waste stream. Wastewater samples were collected from an ISCO 9800 sampler. For all other parameters, 24-hour composite samples were obtained through the time proportional composite sampling techniques and will be representative of the average wastewater characteristics during the compositing period.

Each of the four ISCO Units were programed so that they collect 96 discrete aliquots at a constant time interval over 24 hours (every 15 minutes), with approximately 100-150 mL sampled at a time. Waste stream water were deposited into a 20- liter container over the 24-hour span. Throughout the program the collecting of the time interval was modified to reflect operations. Wastewater samples were run for various chemicals including the following:

• Waste Stream #1 -Metal Series –Aluminum, Arsenic, Cadmium, Chromium III, Chromium VI, Copper, Lead, Mercury, Molybdenum, Nickel, Selenium, Silver, Zinc– Total and dissolved. total suspended solids, total dissolved solids, COD (filtered and unfiltered)
• Waste Stream #2- Cyanide: COD (filtered and unfiltered), Cyanide, ammonia, total and dissolved phosphorus, total suspended solids, total dissolved solids, calcium, magnesium, chloride, sulfate, hardness, silica, metals series.
• Waste Stream #3 acid/Akai: Bis(2-ethylhexylphthalate), Di-n-octylphthalate, total toxic organics
• Waste Stream #4 (Chelate stream): alkanolamine, total organic acids, EDTA -ethylenediaminetetraacetic, oil and grease, Metals series, mercury, hexavalent chromium, COD (total and dissolved), TSS, TDS Proper safety precautions will be observed when collecting waste streams samples. Chemicals that pose specific toxicity or safety concerns and any other relevant safety requirements such as gloves, eye protection, hard hats, and steel-toed boots will be used, as appropriate.

Various sampling issues arose during the project including not enough wastewater being generated and gas fumes increases. Because the way the facility operates, sampling collecting procedures were modified. Because of the new sampling procedures, new hazards were identified that caused the PPE to be upgraded from Level D modified to Level C to respond to air monitoring concentrations.