Water Budget of the Lehigh River - Lafayette College



Laboratory 5 – CE 321, Fall 2009

Water Quality Field Sampling of Bushkill Creek

Objectives

▪ use field and laboratory methods to assess water quality at three to six locations along the Bushkill Creek

o Conductivity

o Macro Invertebrate Study

o pH

o Alkalinity

o Turbidity

o Dissolved Oxygen

o Temperature

▪ relate your results to hydrologic conditions, geology, and land use

Due: Thursday, October 15th

Background

A variety of parameters are used to characterize the water quality of a stream. Some of these, such as the coliform test, must be performed in the lab. Others can be taken in the field using hand-held meters or field kits. pH, temperature, specific conductivity, and dissolved oxygen (DO) are four parameters that are fairly easy to measure in the field. These parameters give a good indication of how suitable the stream is for aquatic life and recreational uses, or how vulnerable the stream might be to wastewater discharges.

In this lab, we will perform field and laboratory tests at a number of locations along the Bushkill Creek (these locations will be at or close to the nine sample locations used by the Bushkill Stream Monitors community outreach program). Refer to the attached map for the sampling locations.

pH is a measure of the acidity of the water; values between 6 and 8.5 are considered healthy. pH is highly dependent on local geology, but is also influenced by rainfall. Highly acidic steams may result from acid rain or acid mine drainage, and are sometimes completely sterile.

Temperature depends on the season, climate, localized inflows of groundwater, and streamside vegetation (shade). The effect of high temperature is seen through lower oxygen solubility, and thus lower DO levels.

Conductivity is a result of dissolved ions (total dissolved solids or TDS) in solution; high conductivity may indicate contamination with salts or inorganic wastes. TDS of fresh water is usually well below 500 mg/L, and again depends on the local geology. Conductivity fluctuates with stream flow, since higher flow rates tend to dilute the concentrations of dissolved solids.

Dissolved oxygen (DO) is required for the functioning of all aquatic ecosystems. Low levels of DO can result from high water temperatures and aerobic degradation of excess organic matter. Problems are most likely to develop during the summer months if DO levels drop below 5-6 mg/L.

Apparatus

pH/temperature meter, conductivity meter, DO meter (back-up Hach DO test kit), Hach alkalinity, turbidimeter, kicknets and buckets for macro study

Procedure

1. At each sample location groups will works together such that each group gets all analytical and biological measurements.

Chemistry

2. Check that the pH meter has been calibrated.

3. At each location, collect a "grab sample" from the stream with a plastic cup. Make sure the water is taken from a location with visible flow, not a stagnant pool.

4. Place the pH/temp and conductivity probes in the plastic cups (do not stick the probes directly into the stream). When the readings have stabilized, record them on the attached sheet. Each location must be sampled twice for pH/temp and conductivity.

5. After calibrating the turbidimeter collect a sample of water, make sure the bottle is clean of finger print and take a reading.

6. Use the Hach test kits to determine DO and alkalinity:

A. DO

▪ Collect a stream sample in the bottle provided, being careful not to trap any air bubbles when you insert the stopper

▪ Add one of each reagent packet, then invert the bottle several times and allow the precipitate to settle halfway

▪ Invert again and allow to settle

▪ Add the contents of the plastic pillow; the precipitate should disappear and the sample should turn yellow

▪ Fill the small tube from the bottle, then transfer into the small glass container

▪ Add sodium thiosulfate drop by drop, counting the number of drops until the solution goes clear

B. Alkalinity

▪ Use the instructions that are in the kit.

▪ You should be working in the high range.

▪ Perform the test using the same degree of color you used in the lab when you compare the results from the kit to the bench top titration method.

Macroinvertebrates

7. Use the kick net to take a 3 minute sample from a riffle…just as in lab 3.

8. Count numbers of macros in each category (sensitive, tolerant, and somewhat tolerant). Return the macros to the stream after you are done.

Record you data on the following field tables.

|Date - |Sample Site - |Weather - |

|pH |Temperature |Conductivity |Turbidity |Nitrate |Alkalinity |DO |

| | | | | | | |

| |

|Bug |Count |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

|Date - |Sample Site - |Weather - |

|pH |Temperature |Conductivity |Turbidity |Nitrate |Alkalinity |DO |

| | | | | | | |

| |

|Bug |Count |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

|Date - |Sample Site - |Weather - |

|pH |Temperature |Conductivity |Turbidity |Nitrate |Alkalinity |DO |

| | | | | | | |

| |

|Bug |Count |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

Write-up

General Format

All reports must be typed with line spacing at 1.5 lines on a word processor (to facilitate editing) and submitted on standard weight 8 1/2" x 11" pages. One or both sides of the page may be used, depending upon the capability of the printer. The font should be12 point and should be easily readable. If sheets supplied in the laboratory manual or by the instructor are used for any portions of the assignment, all requested information should be included in the spaces provided. Margins should be one inch on all sides unless the report is to be bound, in which case the left-hand margin should be 1.5 inches. Neatness and readability should both receive high priority during the preparation of the final copy. Material should be arranged in the order listed, and be securely stapled or bound.

Headings

In the body of the report, utilize headings and sub-headings in any style you feel appropriate, but be consistent throughout. As a suggestion, major headings (e.g., INTRODUCTION) could be centered and capitalized while sub-headings could be left justified and include both upper and lower case (e.g., Background). Allow adequate breaks between sections and sub-sections or new sections, but it is not necessary to start a new page for each section.

Spelling and Grammar

The use of spell-check software is expected, and the use of additional editing software is very strongly encouraged. In either case, careful proof-reading (preferably by someone other than the author) is essential.

Style

The use of slang, colloquial forms, shop-talk and other informal phrases is generally not acceptable. Either passive voice or active voice may be used, but the voice should be consistent throughout the document. Each paragraph in a report should express only one essential idea or recommendation. Review St. Martin’s handbook or Strunk and White’s “The Elements of Style” for information concerning paragraph structure.

The Laboratory Report

Cover Page - self-explanatory, include title, author(s), date of experiment, date submitted

Introduction and Background - present the purpose of the experiment, the technique used, and its application in environmental engineering.

Methods and Materials - a concise description of the procedure and instruments used to perform the lab

Results - present your data clearly, using properly labeled tables and figures where possible. Also include your original data sheet.

Discussion and Conclusions - interpret your results and give their significance in the context of engineering. Incorporate your answers to my questions and calculations in this section. Discuss any deviations of your results from expected values.

Literature Cited - all reference materials must be included

Figures and Tables should appear in the report.

The following requirements apply to all figures and tables:

▪ They must be computer generated (no hand-drawn figures)

▪ Each must have a number and title, and must be referred to in the text (or appendix) of the report. Each figure must be properly referenced to source. Figures and tables must be numbered in the order in which they appear in the text.

▪ They should be self-contained, including sufficient information to allow their effective use even if separated from the body of the text.

▪ On graphs, it is standard practice to use points to represent observed data, and lines to represent theory, equations, or approximations. Data points should be designated with an appropriate symbol (i.e., circles, triangles, etc.). Use legends to distinguish different sets of data points.

Ideas regarding information to be provided

Describe the sample locations and sampling procedures used, and provide a table of your results. Use the correlation provided in class to determine TDS (Total Dissolved Solids) from the conductivity readings. Include a map showing the sample locations. Write an interpretive discussion of your results using the following questions to guide your writing.

Questions to Ponder

Do you see any trends in water quality between sample locations?

Do some parameters vary more than others?

Explain whether or not the observed trends in water quality make sense, based on what you know about the watershed geology, land uses, and recent hydrologic conditions (e.g., rainfall or lack thereof).

Which location(s) of the stream appears to have the best quality, and which have the worst quality, based on these four parameters?

-----------------------

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download