WASTEWATER SAMPLING

he first step in defining pollution control equipment needs is data collection. Flows must be mea- sured, and chemical and biologi- T cal content determined. Reliable

monitoring instruments are necessary for identifying wastewater and groundwater characteristics, and as tools for sizing equipment and quality assurance.

Wastewater monitoring programs may continue after equipmen: is selected mu” installed as a way of controlling waste- water processing and for proof of com- pliance. For example, municipalities that use federal funds to construct and oper- ate waste treatment facilities are required by law to assess users their fair share of treatment costs. Reliable sampling equip- ment enables a facility to show proof of compliance and aid in the development of equitable sewer surcharges.

Within individual facilities, water sam- pling is an integral component in assess- ing the effectiveness of such treatment processes as clarification, aeration and filtration. Water sampling also is used to identify malfunctions and upsets in man- ufacturing processes, and provides a record of accidents and spills. It also can help determine the sources and extent of a manufacturing process’s contribution to the total waste load.

Wastewater characteristics, including pH, turbidity, temperature and conductiv- ity, can be monitored continuously, while other parameters, such as biochemical

JOHN A. KING Environmental Consultant

Harpers Ferry, WV

oxygen demand (BOD), require offsite laboratory analysis. (Samples sent offsite for analysis should be collected in a man- ner consistent with controlled laboratory practices.)

An ideal water sampler would: Extract samples that allow total char- acterization of a water body; Obtain samples in a manner suitable

for storage and later analysis or, if desired, iristimi anaiysis; Take samples in an automated man- ner; Extract samples instantaneously or in a timed sequence; Accept input from a flow-monitoring device and take samples based on flow levels; Be suitable for indoor or outdoor installation; Operate on a variety of power sources-alternating current (AC), compressed air, vacuum, batteries, etc.; Be suitable as a permanent or portable installation; Operate under adverse conditions: Be constructed in a way that limits damage potential by accident or van- dalism; Extract samples from continuous and intermittent flows, open channels, or pressurized or unpressurized pipes: and Lift water from the source to the sam- pling device.

Together, these characteristics describe an ideal analytical instrument. However, most sampling efforts require only some of these characteristics. Actually, such absolute flexibility is not available or necessary; if it were, the cost of such a device probably would limit its marketability.

WATER SAMPLES The most basic water sampling

devices provide a grab sample, which represents a specific point in time. Such samples are collected separately, in their own containers. They can be taken based on a time schedule (every hour, for example) by flow (one grab for every 10,000 gallons) or event (spill, overflow, etc.). They also may be required for spe- cific tests-determining pH or dissolved oxygen content-that cannot be gath- ered from a composite sample.

The simple, or time-based, compos- ite sample is similar to the grab sample. It involves collecting a predetermined volume of water at certain time intervals and storing the samples in a single bot- tle. It often involves a number of small aliquots taken over a specified time period to yield a volume sufficient for analyzing necessary parameters. Flow rates and total flow are not considered when taking these samples, because the same aliquot is collected, regard- less of flow conditions.

-~

34 The National Environmental Journal January/February 1993

WASTE REDUCTION Q & A assures the minimum usage and still assure discharge compli- ance. The selection of a specific chelate-breaker and compan- ion flocculants is dependent upon individual generator requirements. Factory and distributor technicians will be able to assist in developing the most efficient combination.

w e need information on standards and safe limits for gross alpha and beta activity in drinking water, marine and inland discharges of wastewa

The Environmental Protection A imum contaminant levels for radium alpha as follows: combined radium alpha (including radium 226 but excludi 15 pCiA. For beta particles and photon made radionuclides contaminant levels equivalent to the total body or any milliredyr. Specifically, if the aver gross beta activity is less than 50 pCi/L and if the a concentration of tritium and strontium 90 are less p C i and 8 pCi/L, respectively, n If the gross beta activity exceeds 5 contaminants must doses calculated; th standards are the sa

\ 7

Profit Center Management I Senior Project Management

Air Quality - WaterrWastewater - Solid Waste - Hazardous Waste Groundwater - Remediation - Treatment Systems Design

Contacts and Network Second to None!!! Coast to coast, we know what’s going on...

CaN Us First and Find Out!!

REPRESENTATIVE CLIENTS

Chemical Waste Managemenl Ebasco ABB Environmental Melcau& Eddy Brown &Root Bristol-Myers OHM

HDR Engineering Bechlel ATEC Exxon Chemical Malcolm Pirnie Groundwater Technology ESE Brown and Caldwell TRC

Hariling Imwson Associates AS1 EG&G Camp Dresser and McKee Merck EMCON Amoco Dames and Moore Kodak Radian

Schering-Plough Archer Daniels Hoechst Celanese Fluor Daniel

Brian MacLamroc, President / Angela Swope, Assistant 1124 Longmeadow Lane Monroe, NC 28110 H Phone: 704-282-1372 H Fax: 704-282-1374

Circle 156 on card.

\

I I was told to use a NEMA 4 enclosure for an outdoor relay box. Can I substitute with a box of higher NEMA value, a NEMA 6, NEMA 12, etc.?

The NEMA (National Electrical Manufacturers Association) enclosure standards do not necessarily offer more protection with higher number. The following is a brief description of the major types. Type 1 ...... Indoor use, protects against casual contact. Type 2 ...... Indoor use, limited protection from dirt and water. Type 3R ... Outdoor use, limited protection from wind blown

dust, rain and sleet, undamaged by external ice. Type 4 ...... Indoor or outdoor use, protects against wind blown

dust, rain, splashing and hose down, undamaged / by external ice.

T,$pe 4X .... Same as above, plus is corrosion resistant. ype 6 ..... Indoor or outdoor use, can be temporarily sub-

merged.

dripping liquids.

oil and coolants.

I 1 Type 12 .... Indoor use, protects against falling dirt, dust and

Type 13 .... Indoor use, protects against dust, spraying water,

As you can see, a Type 6 might be replaced for a Type 4, but Types 12 and 13 offer less protection and are unsuitable for your circumstance.

For more information on this department, circle 153 on card.

BIOREMEDIATION 021C02 Respirometer

D Measures 0, and CO, consumption/production in 1’ to 80 measuring chambers using a single set of sensors (periodically measures headspace gas concentrations).

0 Temperature of samples can vary during experiment. 0 Allows removal of sample substance from inside of

the chambers during experiment. 0 Superior sensitivity 0.2plih Important for low level

biological activity. D Measuring chambers can be user’s own, 50ml to 10 L. D Real time graphics, fully computerized. CI Measures both liquids or solids. D Programmable air refresh, 24 hour operation.

COLUMBUS INSTR ERNATIONAL “4m9 4T2W USA _ ) - - -

__ PH: (614) 276-0861 9 TLX:246514

Circle 131 on card.

The National Environmental Journal January/February 1993 33

Similar to the time-based composite is the flow-proportioned composite sample, which also involves several extractions collected in a common sam- ple vessel. The collection interval, how- ever, is not pre-selected. Instead, the water sampler is installed in conjunction with a flow monitoring instrument and is set to extract samples at predetermined flow increments. This provides a com- posite sample with fewer aliquots from periods of low flow and more during periods of high flow.

Flow-proportioned composite samples require a much more elaborate station setup and greater initial capital outlays. They can be obtained by collecting the same amount of water at irregular time intervals or by varying the volume at reg- ular time intervals. A detailed analysis of each application should be conducted before instituting this more expensive and elaborate sampling procedure. How- ever, this method does provide the most representative sample for a prescribed time period.

Another option is the sequential sample, which usually is taken by an automatic instrument, where water is extracted on a timed or flow basis and collected in a series of individual con- tainers. Several samples often are col- lected in one container, and the next batch collected in a separate one. A sequential sample frequently is used when it is necessary to extract samples that represent the flow each hour for a set time period and analyze them sep- arately. It also can be used for collect- ing separate samples for specified flow intervals.

The fourth and finai option is the con- tinuous sample, which often is used in pilot-plant work, when larger volumes are required. In most applications, the volume of water collected by continu- ous sampling is too cumbersome to handle; a minimum volume must be col- lected over a certain time period to pro- vide a representative sample.

The type of sample chosen depends on a variety of factors, including vol- ume, flow, time and collection equip- ment. Financial considerations also are

\ 1 7

I a driving force.

COMPOSITE vs. SEQUENTIAL SAMPLING

Most water monitoring programs con- sider flow over a given time period. In such cases, a sample averaging water quality over the specified time period is sufficient to quantify the waste; one analysis per parameter is all that is need- ed. Such applications call for a sampler that extracts multiple samples into one

will save vou monev NOW and

Send for this booklet. lonics On-Line Monitors can detect spills that can be very

costly. Not only is the lost product a huge cost factor, but

into thousands of dollars. the process being monitored, Non-manufacturing operations can also

the PAYOUT benefit greatly from short term payouts. lonics period can On-Line Monitoring is able to anticipate the usually be loading and enables adjustments of operat- measured ing conditions to improve overall efficiency. in WEEKS With large plants, savings of thousands of

OR in dollars per week are possible, and based on

If you are looking for ways to cut operating costs, it will pay you to look into IONICS On-Line Monitoring. we'll tell you all about it in our booklet, "Water Quality Monitoring Guide". Write, call or Fax:

nn\rirnnmnntQl i r i n l q t i n n finne onn nftnn ri in ~ I I ~ I I ~ I I I I ~ G ~ ~ ~ ~ I v i u i u i i u i i I I I I G ~ J bail ui iGi i iuii Depending on

Some cases, our experience, probable.

ION IC S, I NCO RP 0 RAT ED INSTRUMENT DIVISION

65 Grove St., Watertown, MA 021 72 Tel: (61 7) 926-2500 Telex: 922473 Fax: (61 7) 926-8254

The National Environmental Journal 35 Circle 132 on card.

container-a composite sampler. In some situations, a particular para-

meter is monitored over successive time periods in order to track variations. In these cases, a sampler is required that automatically extracts successive sam- ples and deposits them in different sam- ple containers-a sequential sampler.

Meanwhile, some samplers on the market extract multiple composite sam- ples over a given time period. These often are set up where a flow-propor- tioned composite sample is desired but

where no flow meter is available to acti- vate a flow-proportioned sampler. In such situations, a sequential sampler can be set up to extract equal volumes that can be compared to flow records in the lab and proportioned prior to analysis.

Frequently, sequential samples are used where composite ones are desired, with the intention of combining individual aliquots in the lab. If a spike or upset is noticed during the sample period, indi- vidual aliquots can be analyzed sepa- rately to investigate irregularities.

' _ b

Each sampling style has its uses. In most cases, capital costs for sequential units are higher than those for compos- ite samplers. However, if individual analysis is necessary, a sequential device is the correct choice.

FLOW-PROPORTIONED vs. TIME INTERVAL

Flow-proportioned samples may be more accurate when more frequent or larger samples are extracted during peri- ods of higher flow. If the variation in flow is extremely large, sequential or multiple composite samples are more appropriate than a composite sample. Flow-monitor- ing equipment increases operating costs, and appropriate links to the sampling unit are not always cost-effective compared to the results, which easily may be obtained using a straight, time-propor- tioned sampling system.

If the liquid being sampled is either of constant flow or consistency, flow-pro- portioned samples are not appropriate, regardless of the cost. Installations should be examined on a case-by-case basis, with cost-benefit analyses for each application. (Flow- measuring devices require periodic maintenance and calibration.)

SAMPLING MECHANISMS Samples are extracted by three basic

methods-mechanical, forced flow and suction lift. Several site-specific consid- erations are important in determining the appropriate technique, including:

Ease of installation:

Resistance to clogging; Ability to clean the equipment; Ability for onsite repairs: Provisions for sample preservation (refrigeration or ice storage); Ruggedness and weatherability; Ability to provide accurate and repeatable samples: Site accessibility; General character of the waste; Flow patterns; and Type and number of analyses to be run on collected samples. A mechanical device may use a cup,

bucket or fixed vessel on a rope or chain to extract samples. It also may extract samples through a self-closing pipe or core. Automated mechanical

scoops; some scoops are shaped to provide automatic flow compositing by extracting varying amounts, depending on depth of flow. Some take constant sample sizes at preset time intervals, while others extract the same volume of water at flow-activated intervals.

~

I

0 C&.!ib:aticfi simplicity;

samplers use revolving, or oscillating, -~

Circle 133 on card.

36 The National Environmental Journal January/February 1993

Forced-flow samplers may rely on pneumatic injection to collect samples, which requires pressurized gas or motorized compressors. They also may rely on submersible pumps, although these can obstruct the flow in a free- flowing stream. They also can extract samples through a valve in a pressur- ized line. This method can provide vary- ing sample volumes based on the pressure in the line.

Suction-lift sampling is the most com- monly used extraction technique. Some suction- lift devices extract samples directly into evacuation bottles. Such setups are explosion-proof but may be restricted by limited Kiting capabilities. Another suction method uses a vacuum pump to draw samples into a metering chamber before forcing them into bot- tles. A third type of suction lift is the positive displacement pump, whose speeds may be changed to vary vol- ume and rate of collection, and which can be reversed to purge the system.

For representative sampling, devices that do not gather samples directly from the stream must maintain solids in sus- pension. This can be accomplished, in part, by positioning the intake in a tur- bulent zone, or extracting in a manner that keeps solids in suspension. Inlet

\ \

lines should be of sufficient size to allow passage of typical solids but not so large as to allow them to settle out. Inlet velocity must be sufficient to keep solids in suspension. Lower velocities allow solids to settle out, while exces- sive ones can produce abnormally high suspended solids during analyses or loss of dissolved gases.

Sampler inlets should contain appro- priate devices to prevent solids from accumulating. If a scoop or dipper is used, it should be raised above the high-level flow, except when the sample is being collected.

Portable units are easy to set up in a wide variety of situations, making them an invaluable asset to a surveillance and monitoring team taking samples from many sources over a short period of time. They operate on a variety of power sources.

Permanent units, on the other hand, may contain a refrigerator or compres- sor, which are too bulky to be incorpo- rated into a portable device. These installations also may feature a perma- nent mount for the inlet lines, which must be incorporated into a facility's design. Unlike their portable counter- parts, permanent units usually operate on AC power.

Selecting the correct water sampling equipment involves a detailed examina- tion of facility conditions. Are multiple samples desired, or will a composite suffice? Will high solids content or large solids hinder sample extraction? Will an in-stream pump, valve or support struc- ture interfere with flow? Will such inter- ferences catch large solids and hinder operation or flow? What power source is available? Does the sampling envi- ronment require an explosion-proof or corrosion-resistant unit? Will the fluid being sampled affect the material of the samples? Will the equipment material affect the sample? Is state-of-the-art equipment necessary? How long must a stream be sampled to extract a repre- sentative sample? Are flow-measuring devices available? Does flow vary enough in volume or consistency to warrant flow compositing? What volume is required to perform the desired analyses? Do samples need immediate preservation or cooling?

Samplers exist to satisfy almost any condition. Once these questions are answered, selection is merely a matter of choosing a manufacturer whose product features the necessary charac-

~

~

-

teristics. 0

Complete Water Quality Monitoring Systems From alkalinity to zinc-Hach offers everything required to build a complete, easy-to-use system for testing: reliable instrument, proven methods (many EPA-approved), premeasured singledose reagents, necessary labware, clear instructioi-is and on-goirig teChnimi support.

Test Kits-Over 200 single- and multiple-parameter kits, including storm water testing

Laboratory Instruments-Spectrophotometers,

Process Systems-On-line systems to monitor turbidity,

PHASE meters, turbidimeters

pH, chlorine, hardness, silica and more

For details, refer to Hachs 1992-93 Products for Analysis catalog or contact

7

r v HACH COMPANY PO. Box389 Loveland, C 0 80539

- 18001 227-4224

Circle 134 on card.

The National Environmental Journal January/February 1993 37

I CASE HISTORIES BIOREMEDIATION OF CONTAMINANTS AT A FORMER

SOLVENT DISPOSAL AREA.

A closed-loop, in situ bioremediation system has again been successful in the restoration of a contaminated site, this time in Suffolk, Virginia, at a site which for many years had been used for disposal of waste paints and laboratory solvents. Wastes were accumulated in drums, and poured onto concrete abut- ments (relics of a previous structure), in the approximate center of the parcel. This practice occurred prior to 1979, and aver- aged disposal of approximately 40 gallons each week.

In 1990, ESE Biosciences, Inc. (EBIO) completed a reme- dial investigation/feasibility study (RVFS) on the site. Based on the assessment, the following site-specific information was made available:

Elevated concentrations of lead, chromium, mercury, barium, and cyanides were present in soils close to and surrounding the concrete abutments. VOCs including meth- ylene chloride, acetone, chloroform, trichloroethylene (TCE), tetrachloroethylene (PCE), and aromatic solvents including toluene, ethylbenzene, and xylenes were also found in elevated concentrations. Groundwater samples collected from monitor wells within the plume contained detectable concentrations of chloroform, TCE, toluene, ethylbenzene, xylenes, acetone, and 1,2- dichloroethylene. Metals in this groundwater included barium and lead, each below regulatory limits. One groundwater sam- ple obtained from a monitor well located away from the dis- posal area contained PCE from an off-site source.

.

HAZARDOUS MATERIALS MANAGEMENT PROGRAM

OSU's Certified Hazardous Materials Management Program has the following objectives:

To provide credentialed recognition to those professionals engaged in the management and engineering control of hazardous materials. To foster continued professional development of hazardous materials managers through continuing education. To facilitate the transfer of knowledge and experience among professionals and organizations vitally concerned with hazardous materials management. To provide government, industry and academia with a mechanism for identifying hazardous materials management professionals who have fulfilled the requirement for a successful professional career.

We offer the CHMM/CHCM certifications through the Institute of Hazardous Materials Management and the Registered Environmental Manager Certification through the National Registry of Environmental Professionals.

:or additional information call 1-405l744-5714 or write Jacki Price )SU Engineering Extension, 512 EN, Stillwater, OK 74078-0532. 'AX # 405l744-5033

Water table elevations across the site were gener- ally shallow ranging from 4 to 7 ft below ground level with a hydraulic gradient of 0.012 ft/ft. The topographic gradient was toward a stream along the boundary of the property. The stream was unaffected. It was determined that

excavation and disposal of selected areas near the abut- ments with elevated concentra- tions of heavy metals would expedite the overall cleanup process. Once accomplished, an in situ biotreatment approach was used to achieve the cleanup standards set forth by the Virginia Department of Waste Management (VDWM).

In November, 1990, EBIO installed and began operating a bioremediation system utilizing their patented Petroclean@ Bioremediation System. The system included four groundwater recovery pumps placed in converted monitor wells to effectively capture and arrest further plume migration; a Petroclean biore- actor sized to treat the anticipated four to eight gpm rate of groundwater flow; a nutrient feed system; pH control; and an effluent recharge system. Recovered groundwater was pumped to the bioreactor where a specially adapted microbial consor- tium of indigenous microorganisms was inoculated and estab- lished on the submerged fixed-film medium. Treated groundwater containing excess nutrients, dissolved oxygen, and microorganisms comprised the effluent sent to the recharge galleries. The closed-loop approach was designed to promote biotreatment both aboveground and below ground.

The bioreactor performed continuously through August, 1992. Evidence for bioactivity included biofilm development in the biore- actor, and bacterial counts in the soil and groundwater. Evidence that closed-loop conditions were maintained was observed by not- ing increasing nutrient concentrations in recovery wells, but no change in peripheral monitor wells. Excellent removal efficiencies were observed both with aromatic (97.7 percent) and chlorinated solvents (96.2 percent). After 16 months of treatment, total chlo- rinated compound contaminants were reduced to an average con- centration of less than 10 ppb in the soils and less than 8 ppb in groundwater. Highest BTEX concentrations at locations on the site were reported to be 6,270 ppb in soils and 18,500 ppb in groundwater. These concentrations were reduced to an average of 787 ppb in the soil and 32 ppb in the groundwater. These remediation results were provided to the VDWM and the site has been filed for closure.

In summary, the biotreatment program successfully and dramatically reduced concentrations of target compounds in groundwater and soil. Some nutrients remain in the soil and groundwater and will remain available to degrade the residual amounts of organic contaminants on site over time. Meanwhile, the bioreactor will be decommissioned and a six month sampling program will be initiated to ensure that complete restoration has been achieved.

ESE Biosciences, Inc., located in Raleigh and Charlotte, NC, and a major subsidiary of Environmental Science and Engineer- ing, Inc., implements its patented biological process called Petro-

Circle 154 on card.

I

.

Cleaff, to treat contaminated soil and groundwater. 0

~

Circle 135 on card. 38 The National Environmental Tournal