Water Quality Sampling Where When How Yeggie Dearborn

Water Quality Sampling Where, When, How Yeggie Dearborn EMSA 22 CCSF

Where to Sample? ? �The sampling point is based on information provided in the SAP and based on the NPDES or other regulatory permit requirement for the project �Discrete discharge- Point source-as close as possible �Upstream and downstream of discharge point �Stormwater run-off –when enough run-off following a rain event has been generated, & where velocity of water is sufficient �Drinking water sampling points ( tap, well water, distribution point) �Recreational water (swimming area, beaches) �Rivers or streams

When to sample �Criteria to consider: �Stage (base flow, High Flow, Low flow) �Seasonality �Rainfall condition �Frequency of sample to be collected at each site �Sampling strategy depends on short term vs slong term monitoring & reconnaissance (preliminary survey of the site)

Field Information: Site description �Useful as background information as well as for return sampling �Monitoring changes over time �Record general description such as pollution source, water characteristics, color, odor, are any vegetatation or live animals in the area, water depth/level. Weather condition etc. .

Sample Source �Drinking water �Storm water �Groundwater �Ambient/river/Ocean/Stream

Common Sampling Methods for Laboratory Analysis �Grab Sample: A discrete, individual sample taken within a short period of time (usually lessthan 15 minutes). e. g Analysis of a grab sample characterizes the quality of a stormwater discharge at a given time of the discharge. �Composite sample: Sample comprised of a series of individual aliquots that have been combined to reflect mean analyte concentrations of the discharge during the sampling period. A composite sample can be developed based on time or flow rate or depth. �For bacterial sampling equipments/sampling bottles MUST be Sterilized!!!

Example of Water Sampling Equipments �Bottles, Beakers, Buckets �Bailers �Peristaltic Pumps and Tubing �Plastic/Teflon “Kemmere sampling device (for metals)

Example of Sample Bottles �Amber bottles (light resistant) �Plastic Bottles (acid washed for chemcials) �Sterile bottles (bacteria) �Vials (VOA) volatile organics

Drinking Water Sampling Basic �Select a faucet (preferably a non-swivel type) in the bathroom or kitchen. �Remove any filters or screens from the faucet tap. �Turn on the cold water and let it run for at least five minutes. Turn off the water. �Disinfect the tap by alcohol wipes. If you do not have a alcohol you may slowly pour boiling water over the tap to thoroughly heat it. This heating kills bacteria on the faucet that might accidentally contaminate your sample.

Drinking Water Sampling Basic �Turn the cold water back on for a few seconds to cool the tap. Adjust the water to produce an even flow. Remove the cap from the sample bottle. Fill with water leave headspace. Few samples may require the sample bottle to be filled completely( dissolved oxygen analysis. ) �If sampling for bacteria use sterile techniques DO NOT SET THE CAP DOWN OR TOUCH THE INSIDE OF THE CAP OR BOTTLE. FILL THE SAMPLE BOTTLE TO THE SHOULDER ONLY. DO NOT let the faucet touch the bottle. �Re-cap the bottle and deliver to the lab as soon as possible. �Always wear gloves!!!!

Storm water sampling basic �Polluted runoff, or stormwater, is the single biggest source of pollution to California's coastal waters. During storms, rainwater runs over dirty streets, . . . �Samples are collected plunging a clean container nearsurface using Grab sampling technique. Usually near the storm drains upstream and downstream of the drain �Samples are sometimes collected directly into sample bottles with headspace. But care must be taken if preservatives are placed in the bottles �Remember same rules of sterility applies if samples are collected for bacterial analysis

Surface Water Sampling Basics �Surface water include (River, streams, lakes, Ocean water) Grab samples or discrete samples are often collected by directly filling the sample bottle dipping the bottle partially in the water For deeper water layers, below about 0. 5 m, dedicated water samplers are used. They are lowered in an open condition on a rope or steel cable and remotely triggered to close. A third option is the use of pumps (e. g. , peristaltic pumps offer the option of collecting larger amounts of water, and may be used together with in-line filtration, thus avoiding contamination (air dust) in the field).

Groundwater sampling �When Sampling for Groundwater from wells, Ideally, a sample valve or spigot will be located in the water pipeline between the wellhead and the water storage or pressure tank. In case of domestic wells, however, the closest access to water from the well is at the exit point of the water pressure tank or at a water faucet inside the house. When testing ground water, the water sample should not be collected from the tap.

Groundwater sampling �Well is purged to remove any stagnant water in the well casing and to ensure that at least 95 percent of the water sample originates from the aquifer formation being sampled �Specialized equipments may be required. �If Groundwater is extracted and stored in a Holding tank, sampling can be directly from the tank without any advance training skills (Source: http: //groundwater. ucdavis. edu/Publications/Harter_ FWQFS_8085. pdf

Sample Preservation �Preservatives: -Nitric acid (e. g. metals, ) -Sulfuric acid (nutrients, Oil and grease) - Hydrochloric acid (Volatile organics) -Sodium Thiosulfate (Coliform/fecal coliforms) -Zinc Acetate/Sodium Hydroxide (dissolved H 2 S) �No Preservatives: (p. H, Conductivity, alkalinity, Total suspended solids Color, odor etc. . )

Quality Control Samples �Quality Control Requirements �field blank �trip Blank for lab analysis �duplicate/replicate samples (Filed analysis/Lab samples) �spiked samples (laboratory) �split and blind samples (prepared in the field and given to lab without lab’s knowledge

Sample Handling �Shipping and Transport -Samples Labeled -Sealed in water tight bags over ice -Packed in coolers -Chain of custody -Holding time- Extremely important for some analytes!!!

Chain of Custody & Field Log Sheets �All samples collected on the field require: � a Chain of Custody (COC) and field-data sheet. �These documents should detail the following information: 1) exact location of the sampling site; 2) information relating to measurement on site and every observation that could have further influence on the study; 3) samples collected during sampling period 4) date and time of collection. �The field-data sheet must be filled in while sampling � the COC is filled once the sampling has been completed.

Chain of Custody

Field Log Sheets

Lab/field sampling Activity �Demonstration of grab sampling techniques �How to prepare for site sampling using a sampling plan questionnaire (Hunter’s Point Ship Yard Scenario). Lab Demonstration: Determination of Total Coliform/E. coli By Presence/Absence method Standard Method of Examination of Water (SM 9223)

Sampling Plan: Hunter’s Point Ship Yard Scenario �Hunter point ship yard the old Navy Yard has been declared by EPA as a highly Contaminated Area, with designation of Superfund for the site clean up. �You are asked to go to the site and collect groundwater samples from a tank holding the contaminated water for field and lab tests (various parameters). Working in a group, Use the background info on the site GW contaminants and you current knowledge of sampling by answering the Sampling Plan questionnaires provided to determine what you need to do before, during and after the actual sampling. �We will review the scenario in class and come up with strategy for sampling on Parcel B of this ship yard with regard to Groundwater Contaminants present