Water-Quality and Bottom-SedimentChemistry Data for Left Hand Valley 

Reservoir, Boulder County, Colorado, 

January-August 1998

By Robert A. Kimbrough

U.S. GEOLOGICAL SURVEY 

Open-File Report 99-192

Prepared in cooperation with the 

LEFT HAND WATER DISTRICT

Denver, Colorado 

1999
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and does 

not constitute endorsement by the U.S. Geological Survey.

For additional information write to:

District Chief 

U.S. Geological Survey 

Box25046, Mail Stop 415 

Denver Federal Center 

Denver, CO 80225-0046

Copies of this report can be purchased 

from:

U.S. Geological Survey 

Information Services 

Box 25286 

Federal Center 

Denver, CO 80225
CONTENTS

Abstract......................................................................^ 1

Introduction.....................................................^ 1

Purpose and Scope....................................................................................................................................................... 2

Description of the Study Area..................................................................................................................................... 2

Acknowledgments....................................................................................................................................................... 2

Methods of Investigation....................................................................................................................................................... 2

Water-Quality Sampling.............................................................................................................................................. 2

Bottom-Sediment Sampling......................................................................................................................................... 6

Water Quality ........................................................................................................................................................................^ 6

Depth-Profile Measurements....................................................................................................................................... 6

Major Ions and Dissolved Solids................................................................................................................................. 8

Nutrients ............................................................................... 8

Trace Elements................................................................................................................^ 8

Volatile Organic Compounds and n-Nitrosodimethylamine........................................................................................ 11

Bottom-Sediment Chemistry................................................................................................................................................. 12

Summary..................................................................................................................................^ 13

References..................................................................................................................................................^ 13

Water-Quality and Bottom-Sediment-Chemistry Data.......................................................................................................... 15

FIGURES

1-2. Maps showing:

1. Location of Left Hand Valley Reservoir............................................................................................................ 3

2. Location of inflow/outflow ditches and reservoir monitoring sites.................................................................... 4

3-4. Graphs showing:

3. Profiles of water temperature, dissolved oxygen, pH, and specific conductance at sites Rl and R2,

Left Hand Valley Reservoir, January-August 1998........................................................................................... 7

4. Concentrations of dissolved manganese and dissolved oxygen in bottom-water samples from

Left Hand Valley Reservoir, January-August 1998........................................................................................... 11

TABLES

1. Description of monitoring sites and water-quality samples collected in Left Hand Valley Reservoir,

January-August 1998.............................................................................................................................................. 5

2. Summary of water-quality data for major ions, alkalinity, dissolved solids, and nutrients,

Left Hand Valley Reservoir, January-August 1998 ............................................................................................... 9

3. Summary of water-quality data for trace elements, Left Hand Valley Reservoir, January-August 1998............... 10

4. Volatile organic compounds analyzed for but not detected in four water samples

collected from Left Hand Valley Reservoir, January and July 1998....................................................................... 11

5. Summary of selected trace-element concentrations in bottom sediments at

site R2, Left Hand Valley Reservoir, July 27, 1998 ................................................................................................ 12

6. Profile of onsite water-quality measurements for site Rl, Left Hand Valley Reservoir

near south dam, January August 1998.................................................................................................................... 16

7. Profile of onsite water-quality measurements for site R2, Left Hand Valley Reservoir

near north dam, January-August 1998.................................................................................................................... 20

8. Water-quality data for major ions, alkalinity, dissolved solids, nutrients, organic carbon,

fecal coliform bacteria, and chlorophyll a and b, Left Hand Valley Reservoir, January-August 1998.................. 23

9. Water-quality data for trace elements, Left Hand Valley Reservoir, January-August 1998................................... 26

10. Water-quality data for volatile organic compounds and n-nitrosodimethylamine,

Left Hand Valley Reservoir, January and July 1998 ............................................................................................... 28

11. Data for selected constituents in bottom sediments at site R2, Left Hand Valley Reservoir, July 27, 1998........... 29

CONTENTS III
CONVERSION FACTORS, DEFINITIONS, AND ABBREVIATIONS

Multiply

acre

acre-foot (acre-ft)

foot (ft)

gallon (gal)

inch

mile

pound (Ib)

By

0.004047

1,233

0.3048

3.785

2.54

1.609

0.4536

To obtain

square kilometer

cubic meter

meter

liter (L)

centimeter (cm)

kilometer (km)

kilogram (kg)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: 

F=1.8 C+32

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius 

(uS/cm at 25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or 

micrograms per liter (ug/L).

ADDITIONAL ABBREVIATIONS

|ig/g micrograms per gram

H£/L micrograms per liter

\im micrometer

|iS/cm microsiemens per centimeter at 25 degrees Celsius

mg/L milligrams per liter

IV CONTENTS
Water-Quality and Bottom-Sediment-Chemistry Data 

for Left Hand Valley Reservoir, Boulder County, 

Colorado, January-August 1998

By Robert A. Kimbrough

Abstract

From January through August 1998, waterquality and bottom-sediment-chemistry data were 

collected for Left Hand Valley Reservoir, a small 

reservoir (capacity 1,600 acre-feet) located about 

5 miles north of Boulder, Colorado. Water 

temperature, dissolved oxygen, and pH were 

uniform throughout the reservoir water column in 

winter (January and March) but decreased with 

depth during spring and summer. In July and 

August, dissolved oxygen concentrations 

decreased to less than 1 milligram per liter in 

some of the deepest areas of the reservoir. 

Throughout the study, dissolved-solids concentrations were relatively uniform with depth, as indicated by measurements of specific conductance. 

Nitrogen in the water column predominantly was 

in the organic phase, and concentrations of total 

organic plus ammonia nitrogen ranged from 0.1 to 

0.3 milligram per liter. Median concentrations of 

dissolved inorganic nitrogen (ammonia and nitrite 

plus nitrate nitrogen) were less than 0.02 milligram per liter. Total phosphorus concentrations 

ranged from less than 0.01 to 0.059 milligram per 

liter. Dissolved orthophosphorus concentrations 

almost always were less than the detection limit of 

0.001 milligram per liter. With the exception of 

manganese concentrations, maximum dissolved 

concentrations of ten detected trace elements 

ranged from 1 to 46 micrograms per liter. 

Dissolved manganese concentrations in bottomwater samples varied between 2 and 478 micrograms per liter and increased with decreasing 

dissolved oxygen. Volatile organic compounds

and n-nitrosodimethylamine, a metabolite of the 

rocket fuel component 1,1-dimethylhydrazine, 

were not detected in any of four water samples 

collected in January and July. Trace-element 

concentrations in reservoir bottom sediments 

were comparable to background concentrations 

determined from reservoir and streambed sediments in the South Platte River Basin.

INTRODUCTION

Left Hand Valley Reservoir was constructed in 

the early 1950's by the Left Hand Ditch Company to 

provide irrigation water to farms located northeast of 

Boulder, Colorado. Currently (1999), the reservoir is 

used for irrigation, recreation, and as a source of 

drinking water for the Left Hand Water District 

(LHWD). The LHWD uses reservoir water primarily 

during summer to supply drinking water to several 

small communities north of Boulder; however, the 

district is considering using the reservoir as a yearround source of drinking water.

Prior to this study, minimal information on the 

water quality of Left Hand Valley Reservoir existed. In 

recent years, the reservoir had been sampled twice for 

organic solvents and rocket fuel components, which 

may be contained in a plume of ground water and 

seeps located to the west and upgradient from the 

reservoir. The contaminated ground-water plume may 

emanate from a former aircraft facility located about 

1 mile west of the reservoir. In December 1994, relatively low levels of bromoform, vinyl chloride, and the 

rocket fuel hydrazine were detected in Left Hand 

Valley Reservoir. None of these compounds were 

detected in a subsequent sample collected in March 

1996.

Abstract 1
Concerns about the lack of water-quality information and of the potential to increase reservoir withdrawals for drinking water prompted the LHWD to 

acquire additional water-quality data for the reservoir. 

In 1998, the U.S. Geological Survey (USGS), in cooperation with the LHWD, conducted a study to determine the physical and chemical characteristics of 

water in Left Hand Valley Reservoir and to determine 

if organic compounds such as bromoform, vinyl chloride, and rocket fuel metabolites were present in the 

reservoir water column.

Purpose and Scope

This report presents water-quality and bottomsediment-chemistry data for Left Hand Valley Reservoir. At two sites and on seven occasions between 

January and August 1998, depth-profile measurements 

were obtained for water temperature, dissolved 

oxygen, pH, and specific conductance; also, waterquality samples were collected for analysis of major 

ions, alkalinity, dissolved solids, nutrients (nitrogen 

and phosphorus), trace elements, organic carbon, fecal 

coliform bacteria, and chlorophyll. Water-quality 

samples collected from two other sites in January and 

July 1998 were analyzed for volatile organic 

compounds (VOCs) and n-nitrosodimethylamine 

(NDMA), a metabolite of the rocket fuel component 

1,1-dimethylhydrazine. In July 1998, a single sample 

of reservoir bottom sediment was collected for analysis of selected trace elements and several additional 

constituents. Sampling originally planned for 

September 1998-February 1999 was canceled after 

the reservoir was drained for repairs in late August 

1998.

Description of the Study Area

Left Hand Valley Reservoir is situated in the 

Saint Vrain Creek Basin of the South Platte River 

Basin and is located about 5 miles north of Boulder, 

Colorado (fig. 1). The reservoir was created by the 

construction of earthen dams on Dry Creek and one of 

its unnamed tributaries. The bedrock underlying the 

reservoir is the Pierre Shale of Late Cretaceous age 

(Trimble, 1975). The reservoir is primarily filled with 

water diverted from Left Hand Creek through the 

Crocker and Left Hand Filler Ditches (fig. 2). Inflow

from natural sources and the Haldi Ditch (fig. 2) are 

minimal. Water is released from the reservoir back to 

Left Hand Creek and to various irrigation ditches 

through the Left Hand Valley Outlet Ditch (fig. 2). 

When filled to capacity, Left Hand Valley Reservoir 

contains about 1,600 acre-ft of water and the surface 

area is about 110 acres. The mean depth is about 

14.5 ft, and maximum depth is about 35 ft. During the 

study, reservoir storage was filled to capacity 

(1,600 acre-ft) from January through June. Storage 

was less in July and August when the reservoir was 

being drained for darn repairs (end-of-month storage 

for July and August was 1,300 and 0 acre-ft, respectively).

Acknowledgments

The author would like to thank Kathy Peterson, 

of the Left Hand Water District, for providing information and data on the reservoir, and USGS 

employees Dennis Smits and Janet Heiny for their 

assistance with sample collection and processing 

onsite.

METHODS OF INVESTIGATION

Water-Quality Sampling

Physical properties were measured, and water 

samples were collected for analysis of chemical 

constituents at four sites in Left Hand Valley Reservoir 

(sites R1-R4, fig. 2). Most of the data collection 

occurred at two deep sites (Rl and R2). Sampling at 

two shallow sites (R3 and R4) was limited to the 

collection of water for analysis of VOCs and NDMA. 

The shallow sites were located near the sites where 

VOC and NDMA sampling had been conducted in 

March 1996 (Kathy Peterson, Left Hand Water 

District, written commun., 1997). A description of the 

reservoir monitoring sites and a summary of the waterquality samples collected at each site are presented in 

table 1.

To minimize the potential of sample contamination from metallic surfaces and to minimize losses 

through adsorption, sample-collection and sampleprocessing equipment made from acrylic, polyethylene, or Teflon was used. Sampling equipment was

2 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
40°15'

105°15'

01234 5 MILES

I I 

01234 5 KILOMETERS

Figure 1 . Location of Left Hand Valley Reservoir.

METHODS OF INVESTIGATION 3
105°15'

1/2

I

1 

1 KILOMETER

EXPLANATION

1MILE

J

R1

> n ' Reservoir monitoring site and identification number

Figure 2. Location of inflow/outflow ditches and reservoir monitoring sites.

4 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 1 . Description of monitoring sites and water-quality samples collected in Left Hand Valley Reservoir, JanuaryAugust 1998

[USGS, U.S. Geological Survey; maximum depth, maximum depth recorded during this study; major constituents are major ions, alkalinity, and 

dissolved solids; nutrients are nitrogen and phosphorus; NDMA, n-nitrosodimethylamine; Photic, composite sample collected from the reservoir 

photic zone; Bottom, discrete sample collected near the reservoir bottom; , not collected]

Samples collected

Site

number 

(figure 1)

Rl

R2

R3

R4

USGS site

identification 

number

400546105154900

400600105154400

400551105155700

400609105154800

Site name

Left Hand Valley Reservoir

near south dam

Left Hand Valley Reservoir

near north dam

Left Hand Valley Reservoir

near southwest inlet

Left Hand Valley Reservoir

near northeast inlet

Maximum 

depth, 

in feet

35.1

33.9

5.0

12.2

Major

constituents,

nutrients, 

organic 

carbon,

trace

elements

Photic,

Bottom

Photic,

Bottom

Chlorophyll

a and b, 

fecal 

coliform

bacteria

Photic

Photic

Volatile

organic 

compounds, 

NDMA

--

~

Bottom

Bottom

cleaned prior to use with a nonphosphate laboratory 

detergent and rinsed first with tap water, then with a 

5-percent solution of hydrochloric acid, and last with 

deionized water. The equipment was rinsed with 

copious amounts of native water at the sampling sites 

before sample collection. Glass sample containers 

used for organic carbon, VOC, and NDMA analyses 

were cleaned by baking at 450°C for 8 hours and were 

not field rinsed. Water for fecal coliform analysis was 

collected in sterilized, polyethylene containers that 

were not field rinsed.

Prior to sample collection at the deep sites, 

water transparency was measured with a Secchi disc, 

and depth-profile measurements of water temperature, 

pH, dissolved oxygen, and specific conductance were 

obtained with a multiparameter meter. A portable 

computer was used to record depth-profile measurements taken at approximately 1-ft intervals.

Two water samples were collected at each of the 

two deep monitoring sites. The first sample was a 

depth-integrated sample collected from the photic 

zone (defined as twice the Secchi-disc depth) and the 

second sample was collected at a single depth about 

2-3 ft above the reservoir bottom. Water samples were 

collected from discrete depths by using a horizontally 

suspended, 4-L, acrylic Van Dorn sampler. Samples of 

water from the photic zones were collected at the

water surface, and then at about every 2 ft, and were 

composited in a 14-L polyethylene churn splitter.

Samples for VOC and NDMA analysis were 

collected from one depth at each of the two shallow 

sites. Using a peristaltic pump and low-density polyethylene tubing, aliquots of unfiltered water were 

collected in 40-mL glass vials by pumping from a 

depth of about 1 ft above the reservoir bottom. To 

reduce aeration of the sample, water was pumped at a 

low-flow rate and the vials were purged with water for 

at least one minute.

Samples collected from the two deep reservoir 

sites were prepared for analysis onsite by using 

methods described by Horowitz and others (1994), 

Shelton (1994), and Porter and others (1993). Aliquots 

of unfiltered water were collected for analysis of the 

total recoverable concentrations of the constituents 

listed in tables 8-10, at the back of this report. With 

the exception of organic carbon, sample water filtered 

through a 0.45-(im cellulose nitrate filter was used to 

determine constituent concentrations in the dissolved 

phase (herein defined as the dissolved phase). 

Dissolved organic carbon concentrations were determined from water passed through a 0.45-(im silver 

filter. Chlorophyll concentrations were determined 

from suspended material retained on a 0.7-(im glassfiber filter. Samples for trace-element analyses were

METHODS OF INVESTIGATION
acidified to a pH of less than 2 by using ultrapure nitric 

acid; VOC samples were acidified with 1:1 hydrochloric acid. Samples for fecal coliform, nutrient, 

chlorophyll, organic carbon, VOC, and NDMA analyses were immediately chilled to 4°C in the field.

Fecal coliform analyses were conducted by the 

Boulder County Health Department using the Most 

Probable Number method (Jodi Hogan, Boulder 

County Health Department, written commun., 1998). 

The remaining analyses were conducted at the USGS 

National Water-Quality Laboratory in Arvada, Colorado, using methods described by Fishman and 

Friedman (1989), Patton and Truitt (1992), Faires 

(1993), Fishman (1993), and Rose and Schroeder 

(1995). About 15 percent of the total number of 

samples were for quality control. These included field 

equipment blanks, prepared with inorganic- or 

organic-free water, and split-replicate samples.

Bottom-Sediment Sampling

Concentrations of 47 constituents in reservoir 

bottom sediments were determined as part of this 

study. In July 1998, a sample of bottom sediment was 

collected at site R2 by lowering a stainless steel 

Eckman dredge over the side of a boat. Using a Teflon 

spoon, a subsample was collected from the upper 

2-3 cm of sediment that was captured in the dredge. 

The subsample was collected from the center of the 

sampler, away from the metallic sidewalls. On shore, 

the sample was sieved in a mobile laboratory and the 

fraction measuring less than 63 Jim was retained and 

stored at 4°C for analysis. Constituent concentrations 

in reservoir-bottom sediments were determined by the 

U.S. Geological Survey Chemistry Services Group in 

Denver by using total digestion procedures described 

by Arbogast (1990).

WATER QUALITY

Depth-Profile Measurements

The general water-quality properties measured 

in the field for this study were water temperature, 

dissolved oxygen, pH, and specific conductance. 

Depth-profile measurements of the four properties,

obtained at sites Rl and R2, are plotted in figure 3 and 

listed in tables 6 and 7, at the back of this report.

In January and March 1998, water temperature 

was about 4°C throughout the reservoir water column 

(fig. 3). After March, water temperature decreased 

with depth, primarily because of variations in water 

density caused by solar heating at the reservoir 

surface. By July, water temperature varied by about 

10°C throughout the water column, and maximum 

temperatures at the water surface were about 25°C. 

During the study, no temperatures exceeded 30°C, the 

water-quality standard for Left Hand Valley Reservoir 

set by the Colorado Department of Public Health and 

Environment (CDPHE) (1996).

Profiles of dissolved oxygen were similar to 

profiles of water temperature (fig. 3). Dissolved 

oxygen levels were uniformly around 10 mg/L through 

March; but by May, dissolved oxygen began to 

decrease with depth, and during late July and August, 

anoxic (zero oxygen) conditions were measured near 

the bottom of the reservoir. The dissolved oxygen 

standard for Left Hand Valley Reservoir is 5 mg/L; 

however, in Colorado lakes and reservoirs, dissolved 

oxygen standards are intended only for the upper and 

middle strata of the water column (epilimnion and 

metalimnion) and the lower strata (hypolimnion) are 

exempt from the standard (Colorado Department of 

Public Health and Environment, 1996).

Throughout the water column, pH, a measure of 

the hydrogen-ion activity, ranged from 6.5 to 8.4 and 

no values were outside the range of 6.5 to 9.0, the 

water-quality standard set by the CDPHE (1996). 

During January and March 1998, pH was fairly 

uniform throughout the water column (fig. 3). After 

March, pH steadily decreased with depth and the 

lowest values were recorded near the bottom of the 

reservoir in July and August.

Specific conductance is an indirect measure of 

the dissolved-solids concentration. For this study, the 

conversion factor between specific conductance and 

dissolved-solids concentration ranged from 0.57 to 

0.66 and averaged 0.62. On most sampling dates, variations of specific conductance were small throughout 

the reservoir water column (fig. 3), indicating that the 

concentration of dissolved solids was uniformly 

distributed with depth. On a temporal basis, specific 

conductance was higher from January through May 

(213-297 jiS/cm) as compared to July and August 

(80-139|lS/cm).

6 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Jan 29 Mar 10 May 11 June 8 July 13 July 27 Aug 10

20

35

203520

356.520 - 35100

R1 (near 

south dam)

R2 (near 

north 

dam)

10 20 0

5 10 12 0

7.5 8.5 6.5

10 20 15 25 5 15 25 5 15 

WATER TEMPERATURE, IN DEGREES CELSIUS

25 5 25 5

10 12 5 10 0 5 10 0 5 10 0 

DISSOLVED OXYGEN, IN MILLIGRAMS PER LITER

10 0

7.5 8.5 6.5 7.5 8.5 6.5 7.5 8.5 6.5 

pH, IN STANDARD UNITS

8.5 6.5

100 200 300 100 200 300 100

\

200 100 200 0 100 200 0

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER AT 25 DEGREES CELSIUS

15 25

7.5 8.5

100 200

Figure 3. Profiles of water temperature, dissolved oxygen, pH, and specific conductance at sites R1 and R2, Left Hand Valley Reservoir, January-August 1998.
Major Ions and Dissolved Solids

The major ions analyzed for this study (calcium, 

chloride, fluoride, magnesium, potassium, sodium, 

sulfate, and silica) are constituents commonly 

dissolved in most natural waters. Concentrations of an 

additional major ion bicarbonate may be determined from measurements of alkalinity. Summary 

statistics for major-ion and alkalinity concentrations in 

Left Hand Valley Reservoir are listed in table 2. The 

CDPHE has not set standards for major-ion concentrations in the reservoir. Standards for a few constituents 

that have been determined by the CDPHE (1996) for 

upper Left Hand Creek or by the U.S. Environmental 

Protection Agency (USEPA) (1996) for treated 

drinking water are listed in table 2 as a point of reference for the concentrations measured in this study.

The sum of dissolved solids, reported in milligrams per liter, is a direct measurement of the total 

dissolved-constituent concentration. Major ions make 

up the bulk of dissolved-solids concentrations; other 

constituents such as nitrogen, phosphorus, organic 

carbon, and the trace elements listed in table 3 account 

for the remainder. The CDPHE has not set standards 

for dissolved solids in State waters; however, there is a 

USEPA-recommended limit for treated drinking water 

of 500 mg/L (U.S. Environmental Protection Agency, 

1996). Additionally, crop losses might occur when 

dissolved-solids concentrations reach about 

700-850 mg/L in irrigation water (U.S. Department of 

the Interior, 1994). Dissolved-solids concentrations in 

Left Hand Valley Reservoir ranged from 58 to 

174 mg/L (table 2) and no values exceeded the standards cited here.

Nutrients

Nitrogen and phosphorus concentrations in Left 

Hand Valley Reservoir were small. In fact, after March 

1998, the laboratory analytical methods for determining nitrogen and phosphorus concentrations were 

changed to allow for lower detection limits (8 samples 

were analyzed by using higher detection limits, 

20 samples were analyzed by using lower detection 

limits).

Nitrogen in Left Hand Valley Reservoir predominantly was in the organic phase, either as dissolved or 

suspended organic nitrogen. Concentrations of total

organic plus ammonia nitrogen ranged from 0.1 to 

0.3 mg/L (table 2). Concentrations of dissolved inorganic nitrogen, measured as ammonia, and nitrite plus 

nitrate were about one order of magnitude lower than 

organic concentrations. Median concentrations were 

less than 0.02 mg/L for ammonia and 0.016 mg/L for 

nitrite plus nitrate nitrogen (table 2). The CDPHE 

(1996) has set a standard for un-ionized ammonia that 

is applicable to Left Hand Valley Reservoir. Unionized ammonia concentrations are calculated using 

ammonia concentrations, pH, and water temperature. 

All un-ionized ammonia concentrations were at least 

2 orders of magnitude lower than the standard of 

0.1 mg/L (table 2). Total phosphorus concentrations 

ranged from less than 0.01 to 0.059 mg/L (table 2). 

Concentrations of dissolved orthophosphorus, the 

form of inorganic phosphorus most readily available 

for algal growth, almost always were less than the 

detection limit of 0.001 mg/L. Nitrogen and phosphorus levels were less than standards or guidelines 

that have been established by the CDPHE (1996) and 

by the USEPA (1986) (table 2).

Trace Elements

The term "trace elements" commonly refers to 

substances that almost always occur in concentrations 

less than 1.0 mg/L in natural waters. Eight of the 

18 trace elements analyzed for this study were not 

detected in any samples (table 3). Most dissolved 

concentrations of the 10 detected trace elements were 

less than 10 J^g/L and no concentrations exceeded any 

standards or guidelines that have been established for 

water in Left Hand Valley Reservoir or treated 

drinking water. Aluminum, barium, iron, and manganese were measured at dissolved concentrations 

greater than or equal to 20 |J,g/L. All four of these 

elements are fairly abundant in igneous and sedimentary rocks, and both rock types are common in the 

drainage basin upstream from and surrounding Left 

Hand Valley Reservoir.

Of all the trace elements, the concentrations of 

dissolved manganese were the most variable 

throughout the study (table 3). Dissolved manganese 

concentrations generally were small in samples 

collected from the photic zone, but in samples of 

bottom water, manganese concentrations ranged from 

2 to 478 (ig/L (table 9, at the back of this report).

8 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Graphs of dissolved manganese and dissolved oxygen 

concentrations in bottom-water samples indicate that 

manganese concentrations increased with decreasing 

dissolved oxygen (fig. 4). Manganese concentrations

greater than 100 J-lg/L generally were detected when 

dissolved oxygen levels were less than 2 mg/L at 

depths of 2 to 3 ft off the reservoir bottom (the depths 

at which bottom-water samples were collected).

Table 2. Summary of water-quality data for major ions, alkalinity, dissolved solids, and nutrients, Left Hand Valley Reservoir, 

January-August 1998

[Concentrations are reported as dissolved unless noted otherwise; , no data; nitrogen species as nitrogen; orthophosphorus as phosphorus; 

<, less than]

Concentration, in milligrams per liter

Constituent Number of 

detections in Minimum 

28 samples

Maximum Median

Standard 

or 

guideline

Major ions, alkalinity, and dissolved solids

Alkalinity

Calcium

Chloride

Dissolved solids

Fluoride

Magnesium

Potassium

Silica

Sodium

Sulfate

Total organic nitrogen plus ammonia

Ammonia

Nitrite plus nitrate

Un-ionized ammonia

Total phosphorus

Orthophosphorus

28

28

28

28

28

28

28

28

28

28

28

22

12

22

22

9

28

10

1.6

58

0.3

2.7

0.5

5.3

2.8

12

Nutrients

0.1

<0.002

<0.005

68

30

6.0

174

0.9

8.9

1.1

10

9.3

62

0.3

0.057

0.14

42

18

2.8

114

0.5

5.4

0.8

5.8

5.8

34

0.2

<0.02

0.016

 all values less than 0.001 ~

<0.01

<0.001

0.059

0.02

0.02

<0.001

--

--

! 250

2500

22

--

-

-

-

! 250

--

30.5 (nitrite)

HO (nitrate)

30.1

50.1

60.05

^ater-quality standard for segment 4 of the Saint Vrain Creek Basin [Left Hand Creek upstream from U.S. Highway 36 (fig. 2)] 

(Colorado Department of Public Health and Environment, 1996).

Secondary maximum contaminant level for drinking water (U.S. Environmental Protection Agency, 1996).

3 Water-quality standard for segment 5 of the Saint Vrain Creek Basin (includes Left Hand Valley Reservoir) (Colorado Department of Public 

Health and Environment, 1996).

Calculated using dissolved ammonia, pH, and water temperature.

5Recommended limit for controlling eutrophication in rivers (U.S. Environmental Protection Agency, 1986).

6Recommended limit for orthophosphate where rivers enter lakes and reservoirs (U.S. Environmental Protection Agency, 1986).

WATER QUALITY
Table 3. Summary of water-quality data for trace elements, Left Hand Valley Reservoir, January-August 1998

[Concentrations are reported as dissolved unless noted otherwise; <, less than; , not computed or no standard or guideline]

Trace element

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Uranium

Zinc

Number of 

detections in 

28 samples

22

0

6

28

0

0

8

0

27

12

0

21

18

0

0

0

17

20

Concentration, in micrograms per liter

Minimum Maximum

<1 40

<1

<1 2

20 46

<1

<1

<1 1

<1

<1 3

<10 20

<1

<1 478

<1 2

<1

<1

<1

<1 4

<1 6

Median

10

<1

31

-

<1

2

<10

2

1

2

2

Standard or guideline

'50-200

26

3 100 (total recoverable)

22,000

24

40.9

3 11

48.9

3 1,000 (total recoverable)

42.4

3 1,000 (total recoverable)

474

3 17

40.18

220 (proposed)

480

Secondary maximum contaminant level for drinking water (U.S. Environmental Protection Agency, 1996).

2Maximum contaminant level for drinking water (U.S. Environmental Protection Agency, 1996).

3Water-quality standard for segment 5 of the Saint Vram Creek Basin (includes Left Hand Valley Reservoir) 

(Colorado Department of Public Health and Environment, 1996).

4Water-quality standard for Left Hand Valley Reservoir calculated with the mean hardness concentration from this study and the 

Table Value Standard equations for segment 5 of the Saint Vrain Creek Basin (Colorado Department of Public Health and 

Environment, 1996).

10 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
1,000

500

200

100

50

20

10

5

2

1

1,000

500

200

100

50

20

10

5

SITE R1 (NEAR SOUTH DAM)

I I I I 

Manganese Oxygen

j___i___i___i___i___i

15

10

0

SITE R2 (NEAR NORTH DAM)

n i i r

15

10

Volatile Organic Compounds and 

n-Nitrosodimethylamine

Samples for analysis of VOCs and NDMA were 

collected in winter (January) and summer (July) at the 

two shallow sites, R3 and R4 (fig. 2). Neither the 

VOCs listed in table 4 nor NDMA was detected in any 

of the four samples (analytical results are listed in 

table 10, at the back of this report). Left Hand Valley 

Reservoir froze over almost completely in January 

1998. The winter sampling was scheduled to occur as 

close to ice-off as possible to maximize the potential 

for detecting VOCs that were trapped below ice cover. 

The winter samples were collected on January 29, 

one day after a large ice cover had melted away from 

most of the reservoir surface (samples at R3 were 

collected at the edge of ice cover). Nonetheless, VOCs 

and NDMA were not detected in January or July.

A M 

1998

Figure 4. Concentrations of dissolved manganese and 

dissolved oxygen in bottom-water samples from Left Hand 

Valley Reservoir, January-August 1998.

Table 4. Volatile organic compounds analyzed for but not detected in four water samples 

collected from Left Hand Valley Reservoir, January and July 1998

[USGS, U.S. Geological Survey]

USGS 

parameter 

code

34496

34501

34536

32103

34541

34566

34571

34506

77652

34030

32101

32104

32102

34301

32105

Compound

1 , 1 -Dichloroethane

1 , 1 -Dichloroethylene

1 ,2-Dichlorobenzene

1 ,2-Dichloroethane

1 ,2-Dichloropropane

1 ,3-Dichlorobenzene

1 ,4-Dichlorobenzene

1,1,1 -Trichloroe thane

1 , 1 ,2-Trichlorotrifluoroethane

Benzene

Bromodichloromethane

Bromoform

Carbon tetrachloride

Chlorobenzene

Chlorodibromomethane

USGS 

parameter 

code

32106

34668

34371

78032

34423

77128

34475

34010

39180

34488

39175

81551

77093

34546

Compound

Chloroform

Dichlorodifluoromethane

Ethylbenzene

Methyl tert-butyl ether

Methylene chloride

Styrene

Tetrachloroethylene

Toluene

Trichloroethylene

Trichlorofluoromethane

Vinyl chloride

Xylene

cis- 1 ,2-Dichloroethylene

trans- 1 ,2-Dichloroethylene

WATER QUALITY 11
BOTTOM-SEDIMENT CHEMISTRY

Although the concentrations of 47 constituents 

in reservoir bottom sediment were quantified, the 

following discussion is limited to 11 selected trace 

elements. Data for all 47 constituents are included in 

table 11 at the back of this report.

Analytical results indicate that concentrations 

for most of the 11 selected trace elements are slightly 

to moderately enriched compared to samples of unaffected fine-grained sediments collected from several 

environments throughout the United States (Horowitz 

and others, 1996) (table 5). However, most concentrations are less than or about equal to background levels 

that have been determined from reservoir and 

streambed sediments in the South Platte River Basin 

(Heiny and Tate, 1997).

Currently, no Federal or State guidelines exist 

for concentrations of trace elements in bed sediment, 

but Canadian guidelines have been established by the 

Ontario Ministry of Environment for trace elements 

considered to be most toxic to aquatic life (Persaud 

and others, 1993). Comparison of trace-element 

concentrations in bottom sediment from Left Hand 

Valley Reservoir to the Canadian guidelines (table 5) 

indicates that concentrations for eight elements exceed 

the Lowest Effect Level (LEL) (arsenic, cadmium, 

chromium, copper, iron, lead, manganese, and zinc). 

The LEL indicates that the sediment is clean to 

marginally polluted, and most sediment-dwelling 

organisms are unaffected by the elevated concentrations. None of the trace-element concentrations 

exceeded the Severe Effect Level (SEL).

Table 5. Summary of selected trace-element concentrations in bottom sediments at site R2, Left Hand Valley Reservoir, 

July 27, 1998

[Concentrations are in micrograms per gram unless noted as percent; %, percent; PSQG, Provincial Sediment Quality Guideline; , no data]

Element

Aluminum (%)

Arsenic

Cadmium

Chromium

Copper

Iron (%)

Lead

Manganese

Mercury

Silver

Zinc

Concentration

8.5

11

1.8

86

100

4.1

120

590

0.12

0.8

370

Background 

concentration

for South 

Platte River 

Basin1

7.2

7.8

3.3

60

104

4.9

100

1,260

0.03

1.2

450

Nationwide

background 

concentration2

5.5

7

-

51

20

2.8

23

600

0.05

-

88

PSQG

Lowest Effect 

Level3

--

6

0.6

26

16

2.1

31

460

0.2

-

120

PSQG

Severe Effect 

Level4

--

33

9.5

110

110

4.4

250

1,100

2

--

820

1 Determined from reservoir and streambed sediments in the South Platte River Basin (from Heiny and Tate, 1997). 

Nationwide averages for fine-grained bed sediments from around the United States (from Horowitz and others, 1996). 

3Marginally contaminated sediments, guideline developed by the Ontario Ministry of the Environment (Persaud and others, 1993). 

4Highly contaminated sediments, guidelines set by the Ontario Ministry of the Environment (Persaud and others, 1993).

12 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
SUMMARY

Water temperature, dissolved oxygen, and pH in 

Left Hand Valley Reservoir were uniform throughout 

the water column in winter (January and March 1998) 

but decreased with depth during spring and summer. In 

July and August 1998, anoxic (zero dissolved oxygen) 

conditions were measured near the bottom of the water 

column in some of the deepest areas of the reservoir. 

On any given date, dissolved-solids concentrations 

were relatively uniform throughout the water column, 

as indicated by measurements of specific conductance. 

Throughout the study, specific conductance varied 

between 80 and 297 jiS/cm and the lowest values 

occurred in spring and summer (June-August 1998). 

Concentrations of dissolved solids and individual 

major ions did not exceed any water-quality standards 

or guidelines cited in this report.

Nitrogen in Left Hand Valley Reservoir predominantly was in the organic phase, and concentrations of 

total organic plus ammonia nitrogen ranged from 

0.1 to 0.3 mg/L. Median concentrations of dissolved 

inorganic nitrogen species were less than 0.02 mg/L 

for ammonia and 0.016 mg/L for nitrite plus nitrate 

nitrogen. Total phosphorus concentrations ranged 

from less than 0.01 to 0.059 mg/L. Dissolved orthophosphorus concentrations almost always were less 

than the detection limit of 0.001 mg/L.

Eight of the 18 trace elements analyzed for this 

study were not detected in any samples. Most median 

dissolved concentrations of the 10 detected trace 

elements were less than 10 jig/L, and no concentrations exceeded any standards or guidelines that have 

been established for Left Hand Valley Reservoir or for 

treated drinking water. Dissolved manganese concentrations in bottom-water samples ranged between 2 

and 478 jig/L and increased with decreasing dissolved 

oxygen concentrations.

In January and July 1998, samples were 

collected for analysis of VOCs at sites where organiccompound sampling had previously been conducted in 

March 1996. No VOCs or NDMA, a metabolite of the 

rocket fuel component 1,1-dimethylhydrazine, was 

detected in any of the four samples.

Comparison of selected trace-element concentrations in reservoir bottom sediments to Canadian 

sediment guidelines indicates that the reservoir sediments are clean to marginally polluted with respect to 

eight elements (arsenic, cadmium, chromium, copper, 

iron, lead, manganese, and zinc). However, the traceelement concentrations were comparable to background concentrations determined from reservoir and 

streambed sediments in the South Platte River Basin.

REFERENCES

Arbogast, B.F., ed., 1990, Quality assurance manual for the 

Branch of Geochemistry: U.S. Geological Survey 

Open-File Report 90-668, 184 p.

Colorado Department of Public Health and Environment, 

1996, Classifications and numeric standards for the 

South Platte River Basin, Laramie River Basin, Republican River Basin, and Smoky Hill River Basin 3.8.0: 

Denver, Water Quality Control Commission 5 CCR 

1002-8, 148 p.

Faires, L.M., 1993, Methods of analysis by the

U.S. Geological Survey National Water Quality Laboratory Determination of metals in water by inductively coupled plasma-mass spectrometry: 

U.S. Geological Survey Open-File Report 92 634, 

28 p.

Fishman, M.J., 1993, Methods of analysis by the U.S. 

Geological Survey National Water Quality Laboratory Determination of inorganic and organic constituents in water and fluvial sediments: U.S. Geological 

Survey Open-File Report 93-125, 217 p.

Fishman, M.J., and Friedman, L.C., 1989, Methods for 

determination of inorganic substances in water and 

fluvial sediments: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 5, chap. Al, 

545 p.

Heiny, J.S., and Tate, C.M., 1997, Concentration, distribution, and comparison of selected trace elements in bed 

sediment and fish tissue in the South Platte River 

Basin, USA, 1992-1993: Archives of Environmental 

Contamination and Toxicology, v. 32, p. 246-259.

Horowitz, A.J., Demas, C.R., Fitzgerald, K.K., Miller, T.L., 

and Rickert, D.A., 1994, U.S. Geological Survey 

protocol for the collection and processing of surfacewater samples for the subsequent determination of 

inorganic constituents in filtered water: U.S. Geological Survey Open-File Report 94-539, 57 p.

Horowitz, A.J., Robbins, J.A., Elrick, K.A., and Cook, R.B., 

1996, Bed sediment-trace element geochemistry of 

Terrace Reservoir, near Summitville, southwestern 

Colorado: U.S. Geological Survey Open-File Report 

96-344, 41 p.

Patton, C.J., and Truitt, E.P., 1992, Methods of analysis by 

the U.S. Geological Survey National Water Quality 

Laboratory Determination of total phosphorus by a 

Kjeldahl digestion method and an automated colorimetric finish that includes dialysis: U.S. Geological 

Survey Open-File Report 92-146, 39 p.

SUMMARY 13
Persaud, D., Jaagumagi, R., and Hayton. A.. 1993, Guidelines for the protection and management of aquatic 

sediment quality in Ontario: Toronto, Ontario Ministry 

of the Environment, 24 p.

Porter, S.D., Cuffney, T.F., Gurtz, M.E., and Meador, M.R., 

1993, Methods for collecting algal samples as part of 

the National Water-Quality Assessment Program: 

U.S. Geological Survey Open-File Report 93-409, 

39 p.

Rose, D.L., and Schroeder, M.P, 1995. Methods of analysis 

by the U.S. Geological Survey National Water Quality 

Laboratory Determination of volatile organic 

compounds in water by purge and trap capillary gas 

chromatography/mass spectrometry: U.S. Geological 

Survey Open-File Report 94-708, 26 p.

Shelton, L.R., 1994, Field guide for collecting and 

processing stream-water samples for the National

Water-Quality Assessment Program: U.S. Geological 

Survey Open-File Report 94-455, 42 p.

Trimble, D.E., 1975, Geologic map of the Niwot quadrangle, Boulder County, Colorado: U.S. Geological 

Survey Geologic Quadrangle Map GQ-1229, 1 sheet, 

scale 1:24,000.

U.S. Department of the Interior, 1994, Salinity update: 

Denver, Bureau of Reclamation. Colorado River 

Salinity Program Coordinator, 17 p.

U.S. Environmental Protection Agency, 1986, Quality

criteria for water, 1986: U.S. Environmental Protection 

Agency Report 440/5-86-001, [variously paged].

U.S. Environmental Protection Agency, 1996, Drinking 

water regulations and health advisories, October 1996: 

U.S. Environmental Protection Agency, Office of 

Water, EPA 822-B-96-002, 11 p.

14 Water-Quality and Bottom-Sediment-Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
WATER-QUALITY AND 

BOTTOM-SEDIMENT-CHEMISTRY DATA
Table 6. Profile of onsite water-quality measurements for site R1, Left Hand Valley Reservoir near south dam, 

January-August 1998

[|iS/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance 

(l^S/cm)

PH 

(units)

Temperature 

(degC)

Dissolved 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

(|iS/cm)

PH 

(units)

Temperature 

(degC)

Dissolved 

oxygen 

(mg/L)

January 29, 1998, Secchi-disc depth, 5.3 feet

0.5

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

17.0

213

213

213

213

214

213

214

213

214

214

213

213

214

214

214

214

213

213

7.8

7.8

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

3.0

2.9

2.9

3.0

3.0

3.0

3.2

3.2

3.3

3.3

3.3

3.3

3.3

3.3

3.3

3.3

3.3

3.3

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

33.0

33.7

213

214

214

214

214

214

214

214

214

214

214

214

214

214

215

215

218

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

3.3

3.3

3.3

3.3

3.4

3.4

3.4

3.4

3.4

3.4

3.4

3.4

3.4

3.4

3.5

3.6

3.7

10.4

10.4

10.4

10.4

10.5

10.5

10.5

10.5

10.5

10.4

10.5

10.4

10.4

10.4

10.4

10.4

10.2

March 10, 1998, Secchi-disc depth, 5.8 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

17.5

18.5

234

235

235

235

234

235

235

235

236

235

236

235

236

236

235

235

236

236

7.8

7.8

7.8

7.8

7.8

7.8

7.8

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

2.7

2.7

2.9

3.0

3.0

3.0

3.3

3.3

3.2

3.3

3.3

3.3

3.1

3.1

3.2

3.2

3.5

3.5

10.4

10.4

10.4

10.4

10.5

10.5

10.4

10.6

10.6

10.6

10.7

10.8

10.9

10.9

10.9

10.9

10.9

10.9

19.5

20.5

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

33.0

34.0

34.6

235

235

236

235

236

236

235

236

236

236

237

236

236

237

236

237

239

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

3.5

3.6

3.6

3.6

3.6

3.6

3.7

3.7

3.7

3.7

3.7

3.7

3.7

3.7

3.7

3.8

3.7

10.9

10.9

11.0

11.0

10.9

11.0

11.0

11.0

11.0

11.1

11.1

11.1

11.1

11.1

11.0

11.0

10.9

16 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 6. Profile of onsite water-quality measurements for site R1, Left Hand Valley Reservoir near south dam, 

January-August 1998 Continued

[|iS/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance

(MS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

(US/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

May 11, 1998, Secchi-disc depth, 7.0 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

17.0

266

267

266

266

261

263

261

260

258

256

256

254

246

235

239

237

238

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.1

8.1

8.0

8.0

7.8

7.7

7.7

7.7

16.6

16.7

16.5

16.4

14.7

15.0

14.6

14.2

13.9

13.4

13.3

13.1

12.9

12.2

11.8

11.8

11.6

8.0

8.0

8.0

8.0

8.1

8.1

8.1

8.2

8.2

8.1

8.0

8.0

7.9

7.7

7.4

7.4

7.4

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

33.0

235

239

241

245

245

242

242

245

253

255

259

276

279

289

294

297

7.6

7.6

7.6

7.6

7.6

7.5

7.5

7.5

7.5

7.5

7.4

7.4

7.3

7.3

7.2

7.2

11.4

11.2

11.1

11.1

11.0

11.0

10.9

10.9

10.9

10.9

10.7

10.7

10.3

10.2

10.2

10.2

7.3

7.3

7.2

7.1

7.1

7.1

7.1

7.0

6.6

6.6

6.5

6.3

5.3

4.9

4.6

4.5

June 8, 1998, Secchi-disc depth, 4.9 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

173

173

173

173

172

171

170

169

168

168

167

168

168

169

169

164

8.1

8.1

8.2

8.2

8.2

8.2

8.2

8.2

8.1

8.1

8.1

8.0

8.0

8.0

8.0

7.9

16.9

16.7

16.5

16.4

16.3

15.9

15.6

15.4

15.0

14.9

14.7

14.6

14.6

14.6

14.5

14.2

7.9

7.9

7.9

7.9

7.9

8.0

7.9

8.0

8.0

7.9

7.9

7.8

7.8

7.8

7.7

7.5

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

164

162

161

160

160

163

162

165

162

164

167

168

173

178

186

204

7.8

7.7

7.6

7.6

7.5

7.5

7.3

7.3

7.2

7.2

7.2

7.2

7.1

7.1

7.1

7.0

14.1

14.0

13.8

13.7

13.7

13.7

13.4

13.4

13.1

12.8

12.7

12.5

12.4

12.3

12.2

11.9

7.5

7.3

7.1

7.1

7.0

6.8

6.5

6.3

6.3

6.3

6.1

6.0

5.7

5.3

4.6

3.3

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTRY DATA 17
Table 6. Profile of onsite water-quality measurements for site R1, Left Hand Valley Reservoir near south dam, 

January-August 1998 Continued

[|4,S/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance 

(nS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

(nS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxyg-sn 

(mg/«.)

July 13, 1998, Secchi-disc depth, 3.6 feet

0.8

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

104

104

104

104

104

104

104

98

97

96

95

94

94

93

93

93

93

8.2

8.2

8.2

8.2

8.2

8.2

8.2

7.9

7.9

7.7

7.5

7.3

7.2

7.2

7.1

7.1

7.1

23.3

23.3

23.1

22.9

22.8

22.5

22.4

21.2

21.0

20.5

20.1

19.8

19.6

19.5

19.2

19.1

19.0

7.0

7.0

7.0

7.0

7.0

6.9

6.8

6.8

6.7

6.4

6.2

6.0

5.8

5.7

5.6

5.5

5.5

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

32.7

93

93

93

93

94

93

94

95

96

96

96

100

106

114

116

124

130

7.0

7.0

7.0

7.0

6.9

6.9

6.9

6.9

6.9

6.9

6.9

6.8

6.8

6.7

6.7

6.7

6.6

18.9

18.8

18.7

18.6

18.6

18.4

18.3

18.2

18.1

18.0

17.9

17.6

17.2

16.6

16.4

15.8

15.5

5.4

5.4

5.3

5.3

5.2

5.1

5.0

4.8

4.8

4.8

4.8

4.2

3.4

2.9

2.6

1.6

0.9

July 27, 1998, Secchi-disc depth, 3.0 feet

1.0

2.0

3.0

4.5

5.0

6.5

7.0

8.0

9.0

10.0

11.0

12.0

13.0

15.0

17.0

100

100

100

101

99

94

93

92

91

91

93

93

92

91

91

8.2

8.2

8.2

8.2

8.0

8.0

7.6

7.6

7.4

7.4

7.1

7.1

7.1

7.1

7.1

23.3

23.3

23.2

22.9

21.7

21.6

21.4

21.3

20.8

20.8

20.6

20.5

20.4

20.2

20.2

7.2

7.2

7.2

7.3

7.0

7.0

6.6

6.5

6.3

6.4

5.5

5.5

5.8

5.6

5.7

19.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

32.8

92

92

92

92

93

93

93

95

96

99

106

113

117

121

6.9

6.8

6.8

6.9

6.9

6.9

6.8

6.7

6.6

6.6

6.5

6.5

6.5

6.5

19.8

19.7

19.7

19.7

19.5

19.4

19.4

19.2

18.6

18.2

17.7

17.0

16.6

16.4

5.0

4.8

4.9

5.5

5.1

5.0

4.8

3.9

2.8

2.4

1.2

0.5

0.0

0.0

18 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 6. Profile of onsite water-quality measurements for site R1, Left Hand Valley Reservoir near south dam, 

January-August 1998 Continued

[|aS/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance

(pS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

Depth 

(feet)

Specific 

conductance 

(pS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

August 10, 1998, Secchi-disc depth, 4.2 feet

 .8

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.1

11.3

12.0

127

127

127

127

127

127

126

126

128

130

130

132

129

7.9

8.0

8.0

8.0

7.9

7.9

7.9

7.9

7.9

7.7

7.7

7.6

7.4

23.1

23.1

23.0

22.7

22.7

22.6

22.6

22.5

22.2

22.1

22.1

21.5

21.4

7.0

7.0

6.9

7.0

6.9

6.9

6.9

6.9

6.7

6.5

6.4

6.2

5.9

13.0

14.0

15.0

16.0

17.0

18.0

19.0

20.0

21.0

22.0

23.0

23.1

117

117

117

117

117

117

118

116

115

117

123

123

7.4

7.2

7.1

7.0

6.9

6.8

6.8

6.7

6.6

6.6

6.6

6.6

21.0

20.8

20.7

20.5

20.3

20.1

19.8

19.4

19.1

18.1

17.5

17.5

5.5

4.9

4.8

4.2

3.8

3.2

2.5

1.6

0.6

0.1

0.0

0.0

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTFT DATA 1 9
Table 7. Profile of onsite water-quality measurements for site R2, Left Hand Valley Reservoir near north dam, 

January-August 1998

[|0,S/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance 

((iS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

((iS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/U

January 29, 1998, Secchi-disc depth, 5.0 feet

0.5

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

214

214

214

214

214

214

214

214

214

214

214

214

214

214

214

214

214

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

3.3

3.3

3.3

3.3

3.2

3.2

3.3

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

10.6

10.6

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

10.5

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

214

215

214

214

214

214

214

214

215

216

216

217

219

225

232

250

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.9

7.8

7.8

7.8

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.2

3.3

3.3

3.3

3.3

3.4

3.4

3.4

3.5

10.5

10.5

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.4

10.3

10.3

10.2

10.1

March 10, 1998, Secchi-disc depth, 5.5 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

234

235

236

236

235

236

236

236

236

236

236

236

236

236

236

236

7.9

7.9

7.9

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

3.5

3.4

3.6

3.6

3.6

3.6

3.6

3.6

3.6

3.5

3.5

3.6

3.6

3.5

3.5

3.5

10.6

10.6

10.7

10.7

10.8

10.8

10.9

10.9

10.8

10.9

11.1

11.2

11.0

10.9

10.9

10.8

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

30.7

237

236

236

237

237

237

237

238

237

238

238

238

239

256

254

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

8.0

7.9

7.9

7.9

7.9

7.7

7.7

3.5

3.5

3.5

3.5

3.5

3.5

3.5

3.5

3.6

3.5

3.6

3.6

3.7

3.7

3.7

10.9

10.7

10.6

10.6

10.6

10.6

10.5

10.5

10.5

10.5

10.5

10.4

10.3

9.9

9.7

20 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 7. Profile of onsite water-quality measurements for site R2, Left Hand Valley Reservoir near north dam, 

January-August 1998 Continued

[H-S/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance 

(nS/cm)

PH 

(units)

Temperature 

(degC)

Dissoived 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

(nS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

May 11, 1998, Secchi-disc depth, 6.5 feet

0.5

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

264

264

263

262

261

254

252

251

255

262

259

258

253

249

239

239

232

8.2

8.2

8.3

8.3

8.3

8.3

8.3

8.2

8.3

8.3

8.3

8.2

8.1

8.1

7.9

7.9

7.8

16.0

16.2

15.9

15.6

15.2

15.1

14.9

14.7

14.4

14.2

14.0

13.6

13.3

13.0

12.4

12.4

11.7

8.1

8.1

8.1

8.1

8.1

8.2

8.2

8.2

8.3

8.3

8.2

8.2

8.0

7.9

7.8

7.7

7.6

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

33.0

231

234

233

232

229

232

233

233

233

229

237

245

247

251

252

255

257

7.7

7.7

7.7

7.7

7.7

7.7

7.6

7.6

7.6

7.6

7.5

7.5

7.5

7.4

7.4

7.4

7.3

11.6

11.5

11.4

11.2

11.2

11.2

11.1

11.0

10.9

10.9

10.7

10.6

10.6

10.5

10.5

10.5

10.4

7.5

7.5

7.4

7.4

7.4

7.4

7.3

7.2

7.2

7.2

7.0

6.6

6.5

6.1

6.0

5.8

5.4

June 8, 1998, Secchi-disc depth, 5.1 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

173

172

172

172

171

171

171

170

168

167

167

168

167

167

165

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.2

8.1

8.1

8.0

7.9

17.0

16.8

16.3

16.2

16.1

16.0

15.9

15.6

14.9

14.8

14.7

14.6

14.5

14.5

14.3

8.1

8.0

8.0

8.0

8.0

8.1

8.0

8.0

8.0

8.0

8.0

7.8

7.8

7.7

7.6

16.0

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

164

162

160

159

159

159

159

149

150

150

150

146

150

154

157

7.8

7.8

7.7

7.7

7.6

7.6

7.6

7.6

7.6

7.5

7.4

7.4

7.4

7.3

7.2

14.1

14.0

13.9

13.8

13.8

13.8

13.8

13.5

13.4

13.4

13.3

13.2

13.0

12.8

12.7

7.5

7.4

7.3

7.3

7.3

7.3

7.3

7.3

7.2

7.1

7.1

7.0

6.7

6.4

6.1

WATER QUALITY AND BOTTOM-SEDiMENT-CHEMISTRY DATA 21
Table 7. Profile of onsite water-quality measurements for site R2, Left Hand Valley Reservoir near north dam, 

January-August 1998 Continued

tjiS/cm, microsiemens per centimeter at 25 degrees Celsius; deg, degrees; C, Celsius; mg/L, milligrams per liter]

Depth 

(feet)

Specific 

conductance 

(!iS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

Specific 

Depth conduct- 

(feet) ance 

(!iS/cm)

PH 

(units)

Temperature 

(deg C)

Dissolved 

oxygen 

(mg/L)

July 13, 1998, Secchi-disc depth, 3.6 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

103

101

98

98

98

99

97

97

97

95

87

91

90

89

90

90

8.2

8.3

8.3

8.2

8.2

8.2

8.2

8.2

8.1

8.0

7.5

7.4

7.3

7.2

7.1

7.1

23.6

23.3

23.1

22.0

22.1

21.7

21.5

21.4

21.3

21.2

19.9

19.5

19.4

19.1

19.1

19.0

7.0

7.0

6.9

7.0

7.0

6.8

6.8

6.8

6.8

6.8

6.6

6.4

6.1

6.1

5.8

5.9

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

30.7

88

89

90

90

89

89

89

89

85

80

91

94

104

112

122

7.1

7.1

7.1

7.1

7.0

7.0

7.0

7.0

7.1

7.2

7.0

6.9

6.8

6.7

6.6

18.9

18.8

18.7

18.6

18.6

18.4

18.4

18.3

18.1

17.9

17.7

17.6

17.1

16.7

16.1

5.9

5.7

5.7

5.6

5.6

5.5

5.4

5.3

5.6

6.4

4.8

4.3

3.2

2.0

0.9

July 27, 1998, Secchi-disc depth, 2.1 feet

1.0

2.0

3.0

5.0

7.0

9.0

11.0

13.0

15.0

17.0

19.0

100

99

97

98

97

93

93

92

91

91

91

8.4

8.3

8.2

8.2

8.1

7.8

7.6

7.4

7.4

7.4

7.3

23.7

23.7

22.0

21.8

21.6

21.2

20.6

20.4

20.3

20.2

20.0

7.3

7.3

7.2

7.2

7.0

6.9

6.8

6.5

6.5

6.6

6.5

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

30.5

91

92

92

91

91

92

93

95

95

102

102

7.2

7.1

7.1

7.1

7.1

7.0

6.9

6.8

6.7

6.6

6.6

19.7

19.7

19.6

19.5

19.4

19.3

19.2

19.0

18.9

18.2

18.1

6.0

5.9

5.9

6.3

6.3

5.5

5.1

4.6

3.2

2.0

1.9 -

August 10, 1998, Secchi-disc depth, 4.0 feet

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

129

128

129

129

128

129

133

133

133

135

139

7.9

7.9

7.9

7.9

7.9

7.8

7.6

7.5

7.5

7.4

7.4

23.2

23.0

23.0

22.6

22.5

22.4

22.3

22.1

22.1

22.0

21.7

7.0

7.0

7.0

7.0

7.0

6.6

6.4

6.2

6.1

6.1

6.0

12.0

13.0

14.0

15.0

16.0

17.0

18.0

19.0

20.0

21.0

138

136

133

123

119

120

119

119

119

121

7.5

7.3

7.2

7.2

7.1

7.0

6.9

6.8

6.7

6.6

21.5

21.3

21.2

21.0

20.8

20.6

20.3

19.7

19.4

18.8

6.0

5.6

5.3

4.9

4.6

3.7

3.2

2.0

1.0

0.0

22 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 8. Water-quality data for major ions, alkalinity, dissolved solids, nutrients, organic carbon, fecal coliform bacteria, and 

chlorophyll a and b, Left Hand Valley Reservoir, January-August 1998

[MG/L, milligrams per liter; DEG. C, degrees Celsius; NO2+NO3, nitrite plus nitrate; MPN, most probable number; CHLOR, chlorophyll; UG/L, micrograms 

per liter; , no data; <, less than]

DEPTH

AT

SAMPLE

LOCATION,

TOTAL

(FEET)

(81903)

SAMPLING

DEPTH

(FEET)

(00003)

CALCIUM

DISSOLVED

(MG/L

AS CA)

(00915)

CHLORIDE,

DISSOLVED

(MG/L

AS CL)

(00940)

FLUORIDE,

DISSOLVED

(MG/L

AS F)

(00950)

MAGNESIUM,

DISSOLVED

(MG/L

AS MG)

(00925)

POTASSIUM,

DISSOLVED

(MG/L

AS K)

(00935)

SODIUM,

DISSOLVED

(MG/L

2S NA)

(00930)

SITE Rl, 400546105154900 LEFT HAND VALLEY RESERVOIR NEAR SOUTH DAM

1220 34.2 O-lO.i 

1240 34.2 32.1 7.2

1015 35.1

1030 35.1

28 6.5

6.6

1020 32.8

1040 32.8

0-7.2

30.5

0-6.0

31.0

3-8.4

21.5

29

30

18

19

12

12

12

12

15

13

5.9

2.0 0.4 

0.4 

0.3 

0.4

5.4

5.5

3.7 

3.4

3.2

3.3

SITE R2, 400600105154400 LEFT HAND VALLEY RESERVOIR NEAR NORTH DAM

JAN 1998

29. ..

29. ..

MAR

10. ..

10. ..

MAY

11. ..

11. ..

JUNE

08. ..

08. ..

JULY

13. ..

13. ..

27 ...

27. ..

AUG

10. ..

10. ..

1340

1400

1115

1130

1100

1130

1130

1150

1210

1230

1320

1330

1150

1210

33,

33,

31,

31,

33,

33 ,

30,

30,

31,

31,

31,

31,

21,

21,

.9

.9

.2

.2

.0

.0

.5

.5

.2

.2

.0

.0

.5

.5

0-10,

32

0-11

28,

0-13

30,

0-10

27

0-7.

28

0-4

29,

0-8.

19

.0

.0

.0

.0

.0

.0

.2

.5

.2

.5

.2

.0

.0

.5

25

30

28

28

29

27

18

16

12

10

11

11

15

14

2.8 

3.4

3.3 

3.5

4.0 

3.4

1.9

0.6 

0.6

7.3 

8.9

7.8

7.9

5.5 

4.8

2.7

8.9

8.3

6.0

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTPY DATA 23
Table 8. Water-quality data for major ions, alkalinity, dissolved solids, nutrients, organic carbon, fecal coliform bacteria, and 

chlorophyll a and b, Left Hand Valley Reservoir, January-August 1998 Continued

[MG/L, milligrams per liter; DEG. C, degrees Celsius; NO2+NO3, nitrite plus nitrate; MPN, most probable number; CHLOR, chlorophyll; UG/L, microg'ams 

per liter; , no data; <, less than]

DATE

SITE Rl,

JAN 1998

29. ..

29. ..

MAR

10. ..

10. ..

MAY

11. ..

11. ..

JUNE

08. ..

08. ..

JULY

13. ..

13. ..

27. ..

27. ..

AUG

10. . .

10. ..

SULFATE 

DISSOLVED

(MG/L

AS S04)

(00945)

SILICA, ALKADIS- LINITY 

SOLVED LAB 

(MG/L (MG/L

AS

SI02)

(00955)

400546105154900 LEFT

44

44

49

49

58

62

34

35

15

14

13

13

19

14

5.6

5.6

5.3

5.3

9.3

9.7

7.4

8.6

5.5

6.5

5.3

6.3

5.7

6.9

AS

CAC03 )

(90410)

SOLIDS,

RESIDUE 

AT 180 

DEG. C 

DISSOLVED

(MG/L)

(70300)

NITROGEN, 

NITRITE 

DISSOLVED

(MG/L

AS N)

(00613)

HAND VALLEY RESERVOIR NEAR

61

60

64

64

57

59

42

43

31

31

30

32

37

37

142

139

149

148

165

174

116

118

63

66

66

65

81

76

<0.01

<0.01

<0.01

<0.01

<0.001

<0.001

0.005

0.003

0.003

0.004

<0.001

0.003

<0.001

<0.001

NITRO- NITROGEN, GEN, 

N02+N03 AMMONIA 

DIS- DISSOLVED SOLVED

(MG/L

AS N)

(00631)

SOUTH

<0.05

<0.05

<0.05

<0.05

0.012

0.048

0.006

0.037

<0.005

0.008

<0.005

0.015

<0.005

<0.005

(MG/L

AS N)

(00608)

DAM

0

0

<0

<0

0

0

0

0

0

0

<0

0

0

0

.04

.03

.02

.02

.009

.030

.002

.025

.004

.010

.002

.024

.003

.057

NITROGEN, AMMONIA + 

ORGANIC 

TOTAL

(MG/L

AS N)

(00625)

0,

0,

0,

0,

0,

0,

0,

0.

0,

0,

0.

0,

0.

0,

.1

.2

.1

.1

.2

.3

.2

.2

.2

.3

. 2

.3

. 2

.3

NITROGEN, AMMONIA + 

ORGANIC 

DIS.

(MG/L

AS N)

(00623)

<0 . 1

<0 . 1

<0 . 1

0.1

0.1

<0 . 1

<0 . 1

0.1

0.1

0.1

0.1

0.1

0.1

0.2

SITE R2, 400600105154400 LEFT HAND VALLEY RESERVOIR NEAR NORTH DAM

JAN 1998

29. ..

29. ..

MAR

10. ..

10. ..

MAY

11. ..

11. ..

JUNE

08. ..

08. . .

JULY

13. ..

13. ..

27 ...

27. ..

AUG

10. ..

10. ..

45

55

49

50

58

54

34

29

14

12

14

14

18

16

5.

5.

5.

5.

9.

10

7.

7.

5.

5.

5.

6.

5.

6.

.4

.5

.3

.5

.2

.5

.7

.5

.8

,4

.2

.8

.2

61

64

65

57

55

42

39

30

29

30

28

40

37

141

167

150 <0.01 

153 <0.01

164 <0.001 

158 <0.001

113

104

63

58

63

64

83 <0.001 

78 <0.001

0.14 

:0.05

:0.05 

cO.05

<0.005 

<0.005

24 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 8. Water-quality data for major ions, alkalinity, dissolved solids, nutrients, organic carbon, fecal coliform bacteria, and 

chlorophyll a and b, Left Hand Valley Reservoir, January-August 1998 Continued

[MG/L, milligrams per liter; DEG. C, degrees Celsius; NO2+NO3, nitrite plus nitrate; MPN, most probable number; CHLOR, chlorophyll; UG/^, micrograms 

per liter; , no data; <, less than]

PHOSPHORUS

TOTAL

(MG/L

AS P)

(00665)

PHOSPHORUS

DISSOLVED

(MG/L

AS P)

(00666)

PHOSPHORUS

ORTHO,

DISSOLVED

(MG/L

AS P)

(00671)

CARBON,

ORGANIC

DISSOLVED

(MG/L

AS C)

(00681)

CARBON,

ORGANIC

TOTAL

(MG/L

AS C)

(00680)

COLIFORM,

FECAL,

EC

BROTH

(MPN)

(31615)

CHLOR-A 

PHYTOPLANKTON

CHROMOTOGRAPHIC

FLUOROMETRIC

(UG/L)

(70953)

CHLOR-B 

PHYTOPLANKTON

CHROMOTOGRAPHIC

FLUOROMETRIC

(UG/L)

(70954)

SITE Rl, 400546105154900 LEFT HAND VALLEY RESERVOIR NEAR SOUTH DAM

= 0.01 

= 0.01

0.014

0.025

0.013

0.029

0.017

0.022

0.021

0.045

0.021

0.026

<0.01 

<0.01

<0.01 

<0.01

1.8

1.7

3.3 

3.1

2.6

2.7

4.2 

4.4

3.9

<2

<2

1.3 

1.8

1.0 

1.6

<2

SITE R2, 400600105154400 LEFT HAND VALLEY RESERVOIR NEAR NORTH DAM

1.01

1.01

1.025

1.045

<0.01 

0.02

1.01

1.01

.01 

.02

.01 

.01

.001

.001

.001

.001

.001

.003

.001

.001

.001

.001

2.5

2.2

2.3

4.3 

4.9

3.0

3.1

<2

11

70

<0.1 

<0.1 

<0.1 

<0.1

<0.1 

<0.1

<0.1

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTRY DATA 25
Table 9. Water-quality data for trace elements, Left Hand Valley Reservoir, January-August 1998

[UG/L, micrograms per liter; <, less than]

DATE

JAN 1998

29. . .

29. . .

MAR

10. . .

10. . .

MAY

11. ..

11. . .

JUNE

08. . .

08. ..

JULY

13. . .

13. ..

27 ...

27. ..

AUG

10. ..

10. ..

JAN 1998

29. . .

29. . .

MAR

10. ..

10. ..

MAY

11. ..

11. ..

JUNE

08. . .

08. ..

JULY

13. ..

13. ..

27. ..

27. ..

AUG

10. . .

10. . .

TIME 

SITE Rl,

1220

1240

1015

1030

1000

1015

1020

1040

1110

1130

1210

1230

1050

1110

SITE R2,

1340

1400

1115

1130

1100

1130

1130

1150

1210

1230

1320

1330

1150

1210

DEPTH 

AT ALUM- ANT I- BERYL- CHROSAMPLE INUM, MONY, ARSENIC BARIUM, LIUM, CADMIUM MIUM, COBALT, 

LOCA- SAM- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DISTION, PLING SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED 

TOTAL DEPTH (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L 

(FEET) (FEET) AS AL) AS SB) AS AS) AS BA) AS BE) AS CD) AS CR) AS CO) 

(81903) (00003) (01106) (01095) (01000) (01005) (01010) (01025) (01030) (01035)

400546105154900 LEFT HAND VALLEY RESERVOIR NEAR SOUTH DAM

34,

34,

35,

35,

33,

33.

32,

32,

33,

33,

33,

33,

23,

23,

. ^

.2

.1

.1

.0

.0

.8

.8

.6

.6

.2

.2

.5

.5

0-10.6

32.0

0-11.6

32.0

0-14.0

30.0

0-9.8

30.0

0-7.2

30.5

0-6.0

31.0

0-8.4

21.5

400600105154400

33,

33,

31,

31,

33,

33,

30,

30

31,

31

31.

31

21,

21.

.9

.9

.2

.2

.0

.0

.5

.5

.2

.2

.0

.0

.5

.5

0-10.0

32.0

0-11.0

28.0

0-13.0

30.0

0-10.2

27.5

0-7.2

28.5

0-4.2

29.0

0-8.0

19.5

37

33

<1

<1

39

13

29

10

9

5

13

5

8

5

LEFT HAND

<1

<1

<1

<1

40

18

28

21

10

7

22

15

10

4

<1 <1 38 <1

<1 <1 38 <1

<1 <1 42 <1

<1 <1 41 <1

<1 1 45 <1

<1 1 46 <1

<1 <1 31 <1

<1 <1 33 <1

<1 <1 21 <1

<1 <1 22 <1

<1 <1 22 <1

<1 <1 24 <1

<1 <1 26 <1

<1 2 26 <1

VALLEY RESERVOIR NEAR NORTH DAM

<1 <1 38 <1

<1 <1 41 <1

<1 <1 42 <1

<1 <1 42 <1

<1 1 44 <1 <

<1 1 44 <1 <

<1 <1 31 <1

<1 <1 29 <1

<1 <1 20 <1

<1 <1 20 <1

<1 <1 21 <1

<1 <1 24 <1

<1 <1 28 <1 <

<1 1 28 <1

:1 1 <1

:1 1 <1

:1 1 <1

:1 1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 1 <1

:1 1 <1

:1 1 <1

:1 1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

:1 <1 <1

;1 <1 <1

;1 <1 <1

26 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Vaiiey Reservoir, Bouider County, Colorado, January-A ugust 1998
Table 9. Water-quality data for trace elements, Left Hand Valley Reservoir, January-August 1998 Continued

[UG/L, micrograms per liter; <, less than]

DATE

COPPER,

DISSOLVED

(UG/L

AS CU)

(01040)

IRON,

DISSOLVED

(UG/L

AS FE)

(01046)

LEAD,

DISSOLVED

(UG/L

AS PB)

(01049)

MANGANESE,

DISSOLVED

(UG/L

AS MN)

(01056)

MOLYBDENUM,

DISSOLVED

(UG/L

AS MO)

(01060)

NICKEL,

DISSOLVED

(UG/L

AS NI)

(01065)

SELENIUM,

DISSOLVED

(UG/L

AS SE)

(01145)

SILVER,

DISSOLVED

(UG/L

AS AG)

(01075)

URANIUM

NATURAL

DISSOLVED

(UG/L

AS U)

(22703)

ZINC,

DISSOLVED

(UG/L

AS ZN)

(01090)

SITE Rl, 400546105154900 LEFT HAND VALLEY RESERVOIR NEAR SOUTH DAM

JAN 1998 

29. . . 

29. . .

MAR 

10. . .

10. . . 

MAY

11. .. 

11. . . 

JUNE

JULY

13. ..

13. ..

27. ..

27. .. 

AUG

10. ..

10. ..

20

18

13

13

13

2

24

101

30

110

478

SITE R2, 400600105154400 LEFT HAND VALLEY RESERVOIR NEAR NORTH DAM

JAN 1998

29. . .

29. . .

MAR

10. . .

10. . .

MAY

11. . .

11. . .

JUNE

08. ..

08. ..

JULY

13. ..

13. ..

27. ..

27. ..

AUG

10. . .

10. . .

2

1

1

1

3

3

3

3

2

2

2

2

2

1

<io <;

<io <;

<io <;

<io <;

11 <:

14 <]

<10 <]

19 <]

<10 <]

17 <]

11 <]

15 <]

12 <1

<10 <]

L 2 i <i <:

L 11 2 <i <:

L 2 i <i <:

L 10 i <i <:

L 3 i <i <:

L 32 1 <1 <:

L <1 <1 <1 <]

L 29 <1 <1 <]

L <1 <1 <1 <:

L 23 <1 <1 <:

L <i <i <i <:

L 56 <1 <1 <:

L 3 i <i <:

L 114 1 <1 <J

L <1 2

L <1 2

L <1 2

L <1 2

L <1 3

L <1 3

L <1 2

L <1 2

L <1 <1

L <1 <1

L <1 <1

L <1 <1

L <1 1

L <1 <1

<1

6

<1

2

2

4

1

3

<1

3

1

3

<1

1

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTRY DATA 27
Table 10. Water-quality data for volatile organic compounds and n-nitrosodimethylamine, Left Hand Valley Reservoir, Jar-jary 

and July 1998

[UG/L, microgram per liter; UNFLTRD, unfiltered; REC, recoverable; <, less than]

DATE

SITE

JAN 1998

29. ..

JULY

27. ..

SITE

JAN 1998

29. ..

JULY

27. ..

DATE

SITE

JAN 1998

29. ..

JULY

27. ..

SITE

JAN 1998

29. . .

JULY

27. ..

DATE

SITE

JAN 1998

29. ..

JULY

27. ..

SITE

JAN 1998

29. ..

JULY

27. ..

TIME

DEPTH

AT

SAMPLE

LOCATION,

TOTAL

(FEET)

(81903)

SAMPLING

DEPTH

(FEET)

(00003)

R3, 400551105155700 LEFT

1130

1130

5.0

4.0

4.0

3.0

R4, 400609105154800 LEFT

1430

1410

FREON113

WATER

UNFLTRD

REC

(UG/L)

(77652)

12.2

9.0

BENZENE

TOTAL

(UG/L)

(34030)

11.2

8.0

BROMODICHLOROMETHANE

TOTAL

(UG/L)

(32101)

1, 1-DICHLOROETHANE

TOTAL

(UG/L)

(34496)

1,1-DICHLOROETHYLENE

TOTAL

(UG/L)

(34501)

BENZENE

0-DICHLOROWATER

UNFLTRD

REC

(UG/L)

(34536)

HAND VALLEY RESERVOIR NEAR

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

HAND VALLEY RESERVOIR NEAR

<0.2

<0.2

BROMOFORM

TOTAL

(UG/L)

(32104)

R3, 400551105155700 LEFT HAND VALLEY

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

R4, 400609105154800 LEFT

<0.2

<0.2

STYRENE

TOTAL

(UG/L)

(77128)

<0.2

<0.2

TETRACHLOROETHYLENE

TOTAL

(UG/L)

(34475)

<0.2

<0.2

TOLUENE

TOTAL

(UG/L)

(34010)

R3, 400551105155700 LEFT

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

CARBON

TETRACHLORIDE

TOTAL

(UG/L)

(32102)

<0.2

<0.2

CHLOROBENZENE

TOTAL

(UG/L)

(34301)

1,2-DICHLOROETHANE

TOTAL

(UG/L)

(32103)

SOUTHWEST

<0.2

<0.2

NORTHEAST

<0.2

<0.2

CHLORODIBROMOMETHANE

TOTAL

(UG/L)

(32105)

RESERVOIR NEAR SOUTHWEST

<0.2

<0.2

<0.2

<0.2

HAND VALLEY RESERVOIR NEAR

<0.2

<0.2

TRICHLOROETHYLENE

TOTAL

(UG/L)

(39180)

<0.2

<0.2

TRICHLOROFLUOROMETHANE

TOTAL

(UG/L)

(34488)

<0.2

<0.2

VINYL

CHLORIDE

TOTAL

(UG/L)

(39175)

HAND VALLEY RESERVOIR NEAR

<0.2

<0.2

R4, 400609105154800 LEFT HAND VALLEY

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

NORTHEAST

<0.2

<0.2

XYLENE

WATER

UNFLTRD

REC

(UG/L)

(81551)

SOUTHWEST

<0.2

<0.2

RESERVOIR NEAR NORTHEAST

<0.2

<0.2

<0.2

<0.2

<0.2

<0.2

1,2-DICHLOROPROPANE

TOTAL

(UG/L)

(34541)

INLET

<0.2

<0.2

INLET

<0.2

<0.2

CHLOROFORM

TOTAL

(UG/L)

(32106)

INLET

<0.2

<0.2

INLET

<0.2

<0.2

CIS-1,2

-DICHLOROETHENE

WATER

TOTAL

(UG/L)

(77093)

INLET

<0.2

<0.2

INLET

<0.2

<0 .2

BENZENE

1,3-DICHLOROWATER

UNFLTRD

REC

(UG/L)

(34566)

<0.2

<0.2

<0.2

<0.2

DICHLORODIFLUOROMETHANE

TOTAL

(UG/L)

(34668)

<0.2

<0.2

<0.2

<0.2

METHYL

TERTBUTYL

ETHER

WATER

REC

(UG/L)

(78032)

<0.2

<0.2

<0.2

<0.2

BENZENE

1, 4-DICHLOROWATER

UNFLTRD

REC

(UG/L)

(34571)

<0.2

<0.2

<0.2

<0.2

ETHYL -

BENZENE

TOTAL

(UG/L)

(34371)

<0.2

<0.2

<0.2

<0.2

TRANS1, 2-DICHLOROETHENE

TOTAL

(UG/L)

(34546)

<0.2

<0.2

<0.2

<0.2

1,1,1-

TRICFLOROETHANE

TOTAL

(UG/L)

(34506)

<0.2

<0.2

<0.2

<0.2

METHYL -

ENE

CHLORIDE

TOTAL

(UG/L)

(34423)

<0.2

<0.2

<0.2

<0.2

N-NITRO

-SODIM"3THYLAMINE

TOTAL

(UG/L)

(34438)

<0 .6

<0.6

<0.6

<0.6

28 Water-Quality and Bottom-Sediment Chemistry Data for Left Hand Valley Reservoir, Boulder County, Colorado, January-August 1998
Table 11. Data for selected constituents in bottom sediments at site R2, Left Hand Valley Reservoir, July 27, 1993

[BOT MAT, bottom material; <63U WS FIELD, wet sieved to less than 63 micrometers in the field; UG/G, microgram per gram, INORG, inorganic; ORG 

+ INORG, organic plus inorganic; <, less than]

ALUMINUM 

BOT MAT 

<63U WS 

FIELD 

PERCENT 

(34790)

ANTIMONY 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34795)

ARSENIC 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34800)

BARIUM 

BOT MAT

<63U WS 

FIELD

(UG/G) 

(34805)

BERYLLIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(34810)

BISMUTH 

BOT MAT 

<63UWS 

FIELD 

(UG/G) 

(34816)

CADMIUM 

BOT MAT 

<63U WS

FIELD 

(UG/G) 

(34825)

CALCIUM 

BOT MAT 

<63U WS

FIELD 

PERCENT 

(34830)

CARBON, 

INORG, 

BOT MAT 

<63U WS 

FIELD 

(PERCENT) 

(49269)

CARBON, 

ORGANIC 

BOT MAT 

<63U WS 

FIELD 

(PERCENT) 

(49266)

CARBON,

OR3 +

INORG,

BOT MAT

<63U WS

FIELD 

PERCENT 

(49267)

CERIUM 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34835)

630 l.: .83 .11 100

CHROMIUM COBALT COPPER PIUM GALLIUM GOLD HOLMIUM IRONLANTHANUM LEAD

MAGNELITHIUM SIUM

BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT BOT MAT 

<63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS

FIELD 

(UG/G) 

(34840)

FIELD 

(UG/G) 

(34845)

FIELD 

(UG/G) 

(34850)

FIELD 

(UG/G) 

(34855)

FIELD 

(UG/G) 

(34860)

FIELD 

(UG/G) 

(34870)

FIELD 

(UG/G) 

(34875)

FIELD 

PERCENT 

(34880)

FIELD 

(UG/G) 

(34885)

FIELD 

(UG/G) 

(34890)

FIELD 

(UG/G) 

(34895)

FIELD 

PERCENT 

(34900)

15 100 20 4.1 59 120 50 1.2

MANGANESE 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34905)

MERCURY 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34910)

MOLYBDENUM 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34915)

NEODYMIUM

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34920)

NICKEL 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34925)

NIOBIUM 

BOT MAT 

<63U WS 

FIELD 

(UG/G) 

(34930)

PHOSPHORUS 

BOT MAT 

<63U WS 

FIELD 

PERCENT 

(34935)

POTASSIUM 

BOT MAT 

<63U WS 

FIELD 

PERCENT 

(34940)

SCANDIUM 

BOT MAT 

<63U WS

FIELD 

(UG/G) 

(34945)

SELENIUM 

BOT MAT 

<63U WS

FIELD 

(UG/G) 

(34950)

SILVER 

BOT MAT 

<63U WS

FIELD 

(UG/G) 

(34955)

SODIUM 

BOT MAT 

<63U WS

FIELD 

PERCENT 

(34960)

590 .12 54 39 22 .1: 15 1.2

STRONTIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(34965)

180

SULFUR

BOT MAT

<63U WS

FIELD

(UG/G)

(34970)

.09

TANTALUM

BOT MAT

<63U WS

FIELD

(UG/G)

(34975)

<40

THORIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(34980)

21

TITANIUM,

BOT MAT

<63U WS

FIELD

PERCENT

(49274)

.39

TIN

BOT MAT

<63U WS

FIELD

(UG/G)

(34985)

<5

URANIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(35000)

12

VANADIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(35005)

170

YTTRIUM

BOT MAT

<63U WS

FIELD

(UG/G)

(35010)

22

YTTERBIUM

BOT MAT

<;63U WS

FIELD

(UG/G)

(35C15)

1

ZINC

BOT MAT

<63U WS

FIELD

(UG/G)

(35020)

370

WATER QUALITY AND BOTTOM-SEDIMENT-CHEMISTRY DATA 29

-fr U.S. GOVERNMENT PRINTING OFFICE: 1999 773-084 / 20065 Region No. 8