STANDARD OPERATING PROCEDURE FOR SPRING AND SEEP SAMPLING

Transcription

1 STANDARD OPERATING PROCEDURE FOR SPRING AND SEEP SAMPLING SSFL Field Sampling Plan

2 TABLE OF CONTENTS PAGE 1. SCOPE AND APPLICATION METHOD SUMMARY INTERFERENCES AND POTENTIAL PROBLEMS EQUIPMENT REAGENTS PROCEDURES Preparation Observations Selecting Sampling Locations Sampling Primary Sampling Procedure Alternative Sampling Procedure for Non-Volatile Analytes Alternative Sampling Procedures for Seeps Without Pools Quality Control Samples Sample Documentation and Records PERSONNEL QUALIFICATIONS HEALTH AND SAFETY i

3 1. SCOPE AND APPLICATION The purpose of this standard operating procedure [SOP] is to inform field personnel about the proper procedures for sampling seeps in and around the SSFL. The following sections contain protocols that are specific to seep sampling as well as references to general guidelines presented in other SOPs for sample collection, data management, and health and safety. These are standard (i.e., typically applicable) operating procedures which may be changed as required to accommodate varying site conditions, equipment limitations or limitations imposed by the procedure. Field personnel should always document the actual procedures employed. 1

4 2. METHOD SUMMARY The procedure for sampling is designed to ensure that collected samples are representative of the groundwater emerging from the subsurface at seeps. Samples are taken from a location close to an observed emergence point. Ideally, groundwater is drawn into a syringe from a depth approximately one to two inches below the surface of the pool associated with the seep and injected into the sample container(s). Samples are immediately labeled and stored in a cooler with ice until they are relinquished to a laboratory courier or shipped to an analytical laboratory. Modifications to this general procedure may be required at certain seeps when laboratory analyses require greater sample volumes; these modifications are described in Section 6 below. 2

5 3. INTERFERENCES AND POTENTIAL PROBLEMS The primary goal in performing seep sampling is to obtain a representative sample of the groundwater emerging at the seep. Field personnel can compromise the integrity of the sample in two primary ways: (1) collecting an unrepresentative sample or (2) by incorrect handling of the sample. Further guidance regarding potential cross-contamination and appropriate materials for sampling equipment can be found in Section 3.3 of the Groundwater Sampling SOP. Some seeps will not provide sufficient flow or will not be physically situated so as to maintain a pool of water at the ground surface. Alternate methods for sampling seeps exhibiting these conditions are described in Section 6. 3

6 4. EQUIPMENT The following equipment must be obtained prior to entering the field: Sample containers (see Table A-II) 60 ml disposable syringes (one per sample) 500 ml stainless steel pouring beaker Cooler and ice Ziploc bags Bubble wrap (for packaging sample bottles before shipping) Unpowdered nitrile gloves Hand trowel or other small shovel Paper towels Fine-point indelible marker GPS unit Tyvek coveralls (for protection against poison oak and other skin irritants, where needed) Snake gaiters (for protection from rattlesnake strikes when hiking through brush) SSFL field radio (if sampling on-site seeps) 4x4 field truck (if necessary for access to remote seeps) Cellular phone Chain of custody forms Custody seals Field report forms Seeps and Springs Data Booklet (publication pending by Dr. Ross Wagner through the University of Guelph) 4

7 5. REAGENTS Reagents may be used for preservation of samples and for decontamination of sampling equipment. The preservatives are specific to the analysis to be performed (Table A-II). The laboratory that will perform the analyses should provide the necessary reagents in the appropriate sample containers. Decontamination solutions are described in the Equipment Decontamination SOP. 5

8 6. PROCEDURES 6.1. Preparation To ensure compliance with established protocols for pre-field documentation, personnel notification, sample submission, and follow-up, the sampler should review relevant sections of the Data Management Plan [DMP]. In addition, the sampler should review: Locations of seeps, access routes, and notification requirements; Photos, written descriptions, and GPS coordinates of the seeps; Topographic maps of areas surrounding the seeps; Sample volumes, bottle types, and preservatives. After all of the necessary pre-field preparation and notifications are completed, the sampler should perform a final check to verify possession of all necessary equipment and supplies (see Section 3) Observations Detailed observations should be recorded on field report forms throughout the sampling event. Before collecting a sample, the sampler should assess and record observations regarding: Spatial extent of the seep pool, if present (i.e. length, width, depth); The approximate rate of flow from the seep (or out of the pool); Water flow into the pool from sources other than the seep. It is especially important to note if a seep is located in a drainage in which there is flow upstream from the seep into the pool. If possible, the nearest upstream rock outcrop crossing the drainage should be identified and observed to see if there is water flow over the top of that outcrop and if there is continuous flow from that point down the drainage and into the pool. Generally, when such upstream flow is present the water in the seep pool would not be expected to be representative of the water emerging from the seep, and the sample would not be analyzed. After the sample has been collected, the sampler should make note of the following: Time; Volume collected; Sampling methods used; Any conditions potentially affecting the representativeness of the sample Selecting Sampling Locations In general, seep sampling locations will have been established prior to the sampling event. Field personnel should collect samples from the established sampling locations. These locations are described in the Seep and Spring Data Booklet (publication pending by Dr. Ross Wagner through the University of Guelph). Information and tools that are useful for finding the seeps include: Photos, descriptions, and other information contained in the Data Booklet GPS unit and seep coordinates Topographic maps 6

9 6.4. Sampling The method outlined in Section is the preferred method for collecting all samples from seeps with a pool that encompasses the seep emergence point. An alternative procedure for collecting samples for non-volatile analytes is outlined in Section 6.4.2, and should be used only when it is impractical to collect large sample volumes using a syringe. Section describes methods that may be required if the seep location or flow rate is such that a pool of water is not present or does not encompass the seep emergence point Primary Sampling Procedure 1) Put on a clean pair of unpowdered nitrile gloves; 2) Remove a clean syringe from its package; 3) Remove the caps from the sample containers; 4) Place the syringe tip at least one inch below the surface of the water at the designated sampling location and fill it slowly by pulling back on the plunger. Avoid drawing sediment or other foreign materials into the syringe; 5) Tilt the sample bottle at an angle and fill it slowly using the syringe until it is nearly full; 6) Turn the bottle upright and continue filling it until a convex meniscus forms above the mouth; 7) Replace the cap immediately; 8) If sampling for VOCs, check for air bubbles by inverting the vial and tapping sharply on it. If bubbles are observed, discard the vial and collect a new sample. 9) Dry the sample bottle using a paper towel (this will help with labeling); 10) Label the sample container with the appropriate sample information using a fine-point indelible marker; 11) Record the sample information on the chain of custody exactly as it appears on the sample label; 12) Place the sample in a sealable plastic bag; 13) Place the sample into a cooler with ice or cool packs (blue ice) Alternative Sampling Procedure for Non-Volatile Analytes Although the preferred method for sample collection is by syringe, it may be impractical to obtain large sample volumes in this manner. If a pool is present at the established sampling location, it may be possible to collect the sample by submerging a stainless steel collection vessel and then transferring the contents to the appropriate sample container. When collecting a sample using this method, the sampler must take extra care to ensure that foreign materials do not enter the collection vessel. The following procedure is only to be used when sampling for analytes other than VOCs, and for which the required sample volume is impractical to obtain using a syringe: 1) Put on a clean pair of unpowdered nitrile gloves; 2) Invert and submerge a clean, stainless steel pouring beaker at the desired sampling location; 3) Slowly rotate the beaker upright so that water flows in; 3) Lift the beaker out of the water and pour the sample into the appropriate container; 4) Repeat steps 3 and 4 until the required volume is obtained; 5) Replace the cap immediately; 6) The remaining steps are identical to steps 9 through 13 in Section above. 7

10 Alternative Sampling Procedures for Seeps Without Pools A seep may emerge from a fracture in a near-vertical rock face, a hillside, the side of a natural drainage, or other such non-horizontal surface. Under these conditions, the water emerging from the seep may flow across the surface downward toward a pool that accumulates beneath the emergence point, or there may be no pool at all. In these circumstances it is preferable, especially if analyzing for VOCs, to collect the sample directly from the fracture or the surface flow as close to the emergence point as possible rather than sampling from the pool if one is present. This may be accomplished by collecting water directly from the fracture or surface with a syringe, by placing a sample bottle or collection vessel directly below the fracture or in the sheet flow, or by using a clean tool (hand trowel, stainless steel wire or rod, etc.) to direct water flow into a sample bottle or collection vessel. A seep may also present as an area of moist sediment without a pool of standing water. In these circumstances, it is permissible to us a clean (see Equipment Decontamination SOP) hand trowel to dig out a depression in the sediment in which groundwater can accumulate and from which a sample can be collected. The sampler should make note of the size of the hole and the rate at which groundwater flows into it Quality Control Samples For each sampling event, additional samples may be required for quality assurance and quality control (QA/QC) purposes. The various types of QA/QC samples are discussed in the Quality Assurance Project Plan (QAPP), Appendix B of the Site-Wide Water Quality Sampling and Analysis Plan. The QA/QC samples to be collected during a particular seep sampling event should be specified in the detailed sampling plan for that event Sample Documentation and Records Details regarding sample documentation including chain-of-custody documentation and procedures, and records of field activities can be found in the Groundwater Sampling SOP and the Sample Management SOP. 8

11 7. PERSONNEL QUALIFICATIONS All field samplers must have taken the 40-hour HAZWOPER health and safety training course and regular refresher courses as required by 29 CFR prior to engaging in any field sampling activities. In addition, field personnel should be familiar with the site-specific hazards and emergency procedures detailed in the health and safety plan. 9

12 8. HEALTH AND SAFETY Many seeps and springs are located in remote areas and are not entirely accessible by roads or trails. Sampling at these locations often requires field personnel to hike through areas that may contain dangerous plant and animal species. In addition, seeps may be located in areas that are surrounded by steep and/or unstable terrain. Field personnel should be familiar with the sections of the health and safety plan that address these hazards, and should always exercise good common sense. 10