PROGRAMS AND PLANS--Guidelines for sampling and analysis of water-quality constituents associated with solids June 22, 1971 QUALITY OF WATER BRANCH TECHNICAL MEMORANDUM NO. 71.09 Subject: PROGRAMS AND PLANS--Guidelines for sampling and analysis of water-quality constituents associated with solids Quality of Water Branch Technical Memorandum 71.05 described the largely self-evident basis for sampling and analyzing the suspended solids phase when investigating water-quality constituents that are known to be associated with suspended solids. Reference was made also to guidelines that would be provided to field offices for use in planning investigations that include these constituents. At a recent meeting of the Branch staff with other Division water quality specialists, constituents of interest were classified geochemically, and recommended interim procedures and methods for the investigation of those constituents were outlined. Decisions made at this meeting reflect the collective knowleoge and opinion of a large cross section of Division research and operations personnel. They also reflect what is believed to be a reasonable balance between the desire for technical exactness and the necessity of practicality in field operations. At the meeting, it was concluded that adequate data for making certain important decisions are not presently available, but possibly can be obtained within the next few months, in time for dissemination of final instructions to be effective at the beginning of the 1972 water year. Pending release of final instructions, the following interim instructions are provided as a basis for conducting investigations of the elements of interest. I. Classification of minor elements or compounds associated with solids: A. Organics, pesticides B. Organics, all others C. Nitrogen and phosphorus D. Inorganic anions 1. Weakly sorbed--selenium (Se), tellurium (Te), boron (B), halogens (Br, I, F). 2. Moderately sorbed--molybdenum (Mo), vanaclium (V), chromium (Cr), arsenic (As), uranium (U). E. Inorganic cations 1. Moderately sorbed--lithium (Li), radium (Ra), strontium (Sr). 2. Strongly sorbed--cesium (Cs), rubidium (Rb), iron (Fe), manganese (Mn), copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd) cobalt (Co), mercury (Hg), silver (Ag), gold (Au), aluminum (Al), nickel (Ni), beryllium (Be). II. Types of investigations: A. Reconnaissance--short one-time evaluation; can provide definition of problems. B. Monitoring--repetitive, continuing measurements; can define variations and trends. C. General resource appraisal--a moderately long-term monitoring program, but with a defined duration; typical of many WRD basin studies . D. Detailed study, topical or areal--an intensive investigation of limited duration. III. Phases which should be studied in WRD investigations: Minor elements or compounds in water can occur in two phases--dissolved, and associated with solids. The solids can, of course, be suspended or on the bed. The phases to be investigated for each of the classes of minor elements or compounds and for each type of investigation are listed below: A. Dissolved or sorbed on suspended solids: 1. Reconnaissance a. Inorganic cations and anions--study both the material in solution and the material sorbed on suspended solids b. Nitrogen and phosphorus--study both phases c. Organics-- Dissolved organic carbon (DOC)--study only the dissolved phase Suspended organic carbon and all other organics--study both phases. 2. Monitoring--same as reconnaissance. 3. General resource appraisal--same as reconnaissance. 4. Detailed study--same as reconnaissance. B. Sorbed on bottom material: Bottom material, especially the fine fraction, serves as an integrator of chemical and biological processes that occur in the stream, and commonly is a useful indicator of the nature of the solids that will be carried by the stream during the early stages of the next significant runoff event. Thus, it should be sampled at lease once at any study site, especially if samples of suspended material cannot be obtained during the early stages of runoff events, Because a new supply of fine material is deposited after each runoff event, a reasonable period of time is required to allow the integration process to take place before sampling. Prediction of the quantity of an element transported with the bedload on the basis of the size distribution of bed-material samples is questionable at present. 1. Reconnaissance--at least one sample of bed material should be collected in the reach studied if suspended-solids samples are not obtained during the early part of a stream rise. 2. Monitoring--bed-material samples not required if suspended solids are adequately sampled; otherwise take at least one sample. 3. General resource appraisal--sample bed material. 4. Detailed study--sample bed material. IV. Analytical techniques: A. Size of filter pore opening--for the present, continue to use 0. 45 um pore size for separating dissolved (liquid) phase from solids phase. B. When to filter a sample--filtering immediately after collection is recommended. Samples must be filtered within 24 hours after collection. C. Recoverable (partial extraction) vs. total destruction-- measurement of the recoverable portion of inorganic constituents is highly recommended. See attached procedure for a description of the analytical technique currently favored to extract and measure the recoverable fraction. Extraction techniques for bed material samples will be provided at a later date. D. Type of filter to be used for separation of dissolved phase from solids phases, and type of sample used for analysis of solids phase: Constituents to Filter To leach from solids, be determined type extract from ___________________________________________________________ Organics-carbon Silver 1/ whole-water sample 1/ Organics-all others Silver whole-water sample Nitrogen & Phosphorus Membrane whole-water sample Inorganic anions Membrane 1/ whole-water sample 1/ Inorganic cations Membrane 1/ whole-water sample 1/ ___________________________________________________________ 1/ Whole-water sample to be used at least through 1971 water year. Extraction techniques for analyzing material retained on the filter pad will be developed and tested. After comparison with whole-water extraction, decision may be revised. A whole-water sample is defined as a representative sample of the water-suspended solids mixture in the cross section of a flowing stream, or in a vertical (or portion of a vertical) of a lake or reservoir. Content of constituent in solids phase must be calculated by difference (content in whole-water sample minus content in dissolved phase). E. A separate sample will be required for determination of the concentration of suspended solids in the whole-water sample. F. The extraction procedures for recoverable inorganic constituents (attached) is applicable to all minor-element inorganic anions and cations that are listed under I., D and E, above. Extraction procedures for pesticides and nutrients (nitrogen and phosphorus) are already in use. V. Sampling A. Generally, sorption capacity per unit weight of solids decreases with increasing particle size. However, due to coatings on coarse grains (coarser than about 0. 5 mm) and aggregation of fine material, the content of the constituents of interest in the coarser size fractions cannot be ignored; the only exception might be in the analysis of bed-material samples for reconnaissance studies (see V., B). B. For reconnaissance bed-material sample, analyze only material finer than 20 ,um (except for organic analysis, separate in field by timed multiple decantations-- instructions will be provided upon request). Samples for organic analysis should not be separated in the field. C. For special purposes, sample benthic organisms and analyze for minor-element content. D. If only the dissolved phase is to be determined and reported, sediment-sampling equipment may not be required. Nevertheless, the sample should be representative of the entire stream cross section or lake vertical. Established chemical-quality sampling procedures should be used. E. When sampling for the suspended-solids phase (whole-water sample), sediment sampling techniques must be used. Procedures outlined in Interagency Committee on Water Resources, Subcommittee on Sedimentation Report 14, and TWRI Book 3, Chapter C2, Field Methods for Measurement of Fluvial Sediment, must be followed. F. Teflon nozzles for sediment samplers are mandatory when collecting samples for the determination of inorganic minor elements, and are acceptable when sampling for the determination of organic constituents. Nozzles will be supplied by this office upon request. We have nozzles for the D-48, DH-59, D-49, and P-61 samplers. G. The black rubber gasket in sediment samplers must be replaced with a silicone-rubber gasket when collecting samples for the determination of minor elements and organics. Silicone-rubber gaskets for the samplers listed above will be supplied by this office upon request. H. One liter is the minimum sample volume required for the determination of minor elements associated with suspended solids. I. Presently used pint milk bottles are satisfactory for the interim for collecting whole-water samples, but the samples should be quantitatively transferred in the field (except when sampling for organics) to an approved screw-top bottle. Samples collected for organic determinations should receive a minimum amount of handling in the field. J. A handscoop made from a cut-out plastic bottle or other straightsided plastic container may be used for reconnaissance sampling of bottom sediments when the stream can be waded. Samples collected should be iced in the field. When sampling bottom sediments with the BM-54 and BMH-60 bed- material samplers, the buckets on the samplers must be thoroughly cleaned before each use, and the rubber gaskets must be replaced by silicone rubber gaskets. Requests for these gaskets should be made through this office. K. The valve mechanism in the P-61 and 63 point samplers may pose a serious contamination problem. Use of point samplers for sampling minor elements should be avoided unless notifed otherwise . The above instructions indicate, in effect, that if a quantitative analysis of constituents associated with suspended solids is to be made, it must be made using a sample that is representative of both the suspended solids and the liquid phase in the cross section sampled. If the required sampling effort cannot be justified, it is better to filter the sample and analyze for the dissolved constituents only. The Quality of Water Branch will be interested in receiving written comments from the field pertaining to the interim guidelines given above. Further guidelines will be forthcoming. W. H. Durum Attachment WRD Distribution A, B, S, FO, PO.