SECTION 6.1 LABORATORY OPERATIONS

6.1.1 GENERAL

Operating a wastewater treatment facility at maximum efficiency requires a knowledge of not only the general treatment process and control, but also a knowledge of the level of wastewater treatment occurring within the plant. Laboratory testing provides a quantitative measure of the level of treatment occurring within the plant. Results from laboratory testing provide useful information that can help the plant operator to evaluate plant performance and operating trends.

The Department of Ecology requires treatment plant operators to provide reports and records including laboratory testing results to demonstrate that the plant is meeting the limitations given in its NPDES Permit.

6.1.2 DESCRIPTION OF FACILITIES

The treatment plant laboratory is located in the Operations Building. The laboratory includes a fume hood, BOD incubator, microscope, refrigerator, analytical balance, vacuum pump, deionized water system, dishwasher, emergency eyewash/shower and various cabinets and counter areas.

6.1.3 ANALYTICAL PROCEDURES

All laboratory analytical procedures and practices must be in accordance with the current edition of the American Public Health Association’s Standard Methods for Examination of Water and Wastewater. Other references are the EPA manual entitled Methods of Chemical Analyses of Water and Wastes and the WPCF manual entitled Simplified Laboratory Procedures for Wastewater Examination. Chemistry for Sanitary Engineers is a good reference for relating analytical parameters to wastewater treatment processes. Regardless of what procedure is adopted, the laboratory technician must follow it exactly. This assures continuity of methodology and allows comparisons with data obtained in the past, and comparison with other treatment plants with respect to performance characteristics. It should be pointed out that relatively minor changes in procedures may yield results significantly different than the norm.

6.1.4 QUALITY CONTROL

Laboratory work can be routinely performed, with acceptable results reported. However, a quality control program should be included during routine testing to ascertain that the laboratory results are correct. This quality control program can include spiking samples with known amounts of a parameter then testing for recovery, running ‘‘unknown’’ samples (known samples prepared by the operator or some outside source), or running performance samples prepared by the Environmental Protection Agency and obtainable from the Region X laboratory

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in Manchester, Washington. A full discussion of quality control may be found in the EPA publication Analytical Quality Control.

6.1.5 DEPARTMENT OF ECOLOGY TESTING REQUIREMENTS

The Washington State Department of Ecology (DOE) requires a minimum level of testing of wastewater treatment parameters. The City will need to test for BOD, TSS, fecal coliform, dissolved oxygen, chlorine residual, copper, ammonia, and pH. These parameters are aimed specifically at determining the overall efficiency of the plant and ascertaining whether the limits of discharge of certain parameters, as outlined in the NPDES permit, are met. A copy of the NPDES permit is found in Appendix 1.

Additional testing of the receiving water for dissolved reactive phosphorus, ammonia, pH, temperature, hardness, and background metals is required by the NDPES permit.

It should be stressed that the DOE parameters are important and the necessary laboratory tests be done with absolute accuracy so that reliable results will be achieved. These tests should be done by an acceptable method such as outlined in Standard Methods and as further dictated by requirement in the NPDES permit.

6.1.6 DATA RECORDS AND REPORTS

General

It is imperative that data records be maintained not only for legal reasons, such as to avoid plant noncompliance with discharge requirements or plant upset from an industrial discharger, but also to maintain an historical log of past plant performance. This log enables the operator to spot trends, such as slow failure of a unit process that might not be noticeable from day-to- day operations. It also helps to keep track of gradual increase in loading from population increases. Certain patterns may occur prior to breakdown of some unit processes which will help anticipate the problem. Remedial action can then be taken.

Raw Data Sheets

To aid laboratory technicians during performance of tests and to organize the recording of data more efficiently, a series of raw data sheets should be used. These will include the measurements necessary to arrive at a final result to be included in a daily summary sheet.

Daily Summary Sheets

One member of the laboratory staff should be assigned to gather the final results from the individual raw data sheets. These final results should be summarized on a final laboratory report sheet.

Monthly Reports

The monthly reports shall be in accordance with Department of Ecology requirements. Current copies of this form should be maintained at the treatment plant at all times, and each month a completed form should be filed with the regional DOE office. A record copy of the reports

6.1-2 ...6.1 LABORATORY OPERATIONS should also be permanently filed at the treatment plant. All items required in the NPDES permit should be included on the monthly report form.

Record and Report Storage

Raw data sheets should be kept in an appropriate file for five years or longer if litigation is pending; they then may be discarded at the discretion of the operator.

6.1.7 SAFETY

Staff should be made aware of the hazards of working with wastewater. Although it is true that laboratory personnel in wastewater treatment plants are less prone to illness because of their ‘‘inoculations’’ with aerosols containing small amounts of organisms, it is nevertheless imperative that laboratory staff exercise caution with respect to wastewater and chemical safety hazards common in wastewater laboratories are as follows:

• Cuts . Cuts, especially on the hands, are an obvious hazard from the standpoint of infection. Use disinfectant after washing thoroughly, then use gloves to keep cut area clean.

• Pipetting . A common laboratory liquid transfer method involves use of pipettes. Pipetting of wastewater and chemical reagents by mouth should not be allowed. Use special Bulb pipette fillets instead.

• Aerosols . Avoid splashing of liquids, especially sewage samples, since small particles may be entrained in the air during splashing.

• Electrical Shock . Several instruments used in the lab are capable of delivering a severe jolt. Exercise normal precautions around electrical equipment.

• Chemicals . Before mixing chemicals, look at the Material Safety Data Sheets (MSDS) for all the chemicals to be mixed. When receiving new chemicals, make sure there are current MSDS sheets shipped for each chemical. Properly file MSDS sheets. A number of reagent chemicals used in lab work are corrosive, flammable, or toxic. It is strongly recommended that gloves be worn when using corrosive materials or chemicals that may be absorbed through the skin. Materials that give off vapors should be used in the fume hood. Safety glasses are highly recommended for use in the lab, since some materials, such as sodium hydroxide, can cause irreparable eye damage in seconds. As a final precaution, do not pour water into concentrated acids, since the resulting heat released can turn the water to steam and cause blowout or spattering of the acid. An emergency shower is located in the lab for use if a worker spills large amounts of chemical on himself or herself.

• Fires . An extinguisher is located in the lab for putting out small fires, and the emergency shower can be used if a worker’s clothes catch fire.

Refer to Section 2.6 for more detailed safety information.

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