Treated Water Levels of Total Trihalomethanes (TTHM) for
EAST BAY MUNICIPAL UTILITY DISTRICT

Water System Total Trihalomethanes Report

REMINDER: Data Purpose: The ICR data were collected as part of a national research project to support development of national drinking water standards. They should NOT be used to determine local water systems compliance with drinking water standards, nor should they be used to make personal judgements about individual health risks.

Units: Sample measurements are taken in micrograms per Liter (ug/L) and are regulated in milligrams per Liter (mg/L). A microgram per Liter is equivalent to one contaminant part per billion (ppb). A ppb can be thought of as one grain of salt in a swimming pool. Data for Total Trihalomethanes, haloacetic acids 5, and bromate are presented in ppb. 1 mg/L = 1000 ug/L, or 0.080 mg/L = 80 ug/L = 80 ppb, which happens to be the TTHM standard in the Stage 1 DBP Rule.

Calculation in Regulations is Different: Comparisons with compliance calculations based on the existing Total Trihalomethanes standard in CFR Part 141.30 may not be warranted since the standard is based on an annual average of public water system quarterly averages and not on treatment plant results as shown here. Also the results here are based on different types of samples.

Results of Zero: A result of zero may indicate that a sample was analyzed, but that the result was less than the lowest value that the analytical method can reliably report.

Treated Water Levels of TTHM for Orinda Fil ter Plant

Water Type	Quarter	Avg(tthm) (ppb)	Min(tthm) (ppb)	Max(tthm) (ppb)
Surface Water	JUL 1997 - SEP 1997	67.7	57.8	81.2
Surface Water	OCT 1997 - DEC 1997	47.2	40.7	56.5
Surface Water	JAN 1998 - MAR 1998	64.3	57.4	74.2
Surface Water	APR 1998 - JUN 1998	49.7	46	54
Surface Water	JUL 1998 - SEP 1998	43.6	41	48.2
Surface Water	OCT 1998 - DEC 1998	35.4	32.3	41.5

Treated Water Levels of TTHM for Upper San Leandro Filter Plant

Water Type	Quarter	Avg(tthm) (ppb)	Min(tthm) (ppb)	Max(tthm) (ppb)
Surface Water	JUL 1997 - SEP 1997	108	100.4	119.8
Surface Water	OCT 1997 - DEC 1997	105.5	102.6	110
Surface Water	JAN 1998 - MAR 1998	115.1	95.7	131.4
Surface Water	APR 1998 - JUN 1998	111.8	99.3	118.3
Surface Water	JUL 1998 - SEP 1998	137.7	121.2	176.9
Surface Water	OCT 1998 - DEC 1998	103.2	95	112

Treated Water Levels of TTHM for Walnut Creek Filter Plant

Water Type	Quarter	Avg(tthm) (ppb)	Min(tthm) (ppb)	Max(tthm) (ppb)
Surface Water	JUL 1997 - SEP 1997	75.9	61.6	89.1
Surface Water	OCT 1997 - DEC 1997	58.1	42.4	67.2
Surface Water	JAN 1998 - MAR 1998	61.5	52.2	68.6
Surface Water	APR 1998 - JUN 1998	54.6	53	56
Surface Water	JUL 1998 - SEP 1998	45.2	39	55.4
Surface Water	OCT 1998 - DEC 1998	36.1	35.3	37.3

Treated Water Levels of TTHM for Sobrante Filter Plant

Water Type	Quarter	Avg(tthm) (ppb)	Min(tthm) (ppb)	Max(tthm) (p pb)
Surface Water	JUL 1997 - SEP 1997	100.6	71.4	121.2
Surface Water	OCT 1997 - DEC 1997	61.9	36.8	73
Surface Water	JAN 1998 - MAR 1998	87.6	81.4	96.3
Surface Water	APR 1998 - JUN 1998	70.1	64.2	73.5
Surface Water	JUL 1998 - SEP 1998	68.1	48	83.1
Surface Water	OCT 1998 - DEC 1998	46.1	41.6	50.3

Treated Water Levels of TTHM for Layfayette Filter Plant

Water Type	Quarter	Avg(tthm) (ppb)	Min(tthm) (ppb)	Max(tthm) (ppb)
Surface Water	JUL 1997 - SEP 1997	60	48	76.7
Surface Water	OCT 1997 - DEC 1997	52.1	42.4	65
Surface Water	JAN 1998 - MAR 1998	59.3	52.4	68.8
Surface Water	APR 1998 - JUN 1998	53.3	49	56
Surface Water	JUL 1998 - SEP 1998	44.1	42	45.2
Not Reported	OCT 1998 - DEC 1998	NO DATA	NO DATA	NO DATA

How does this utility's treated water compare to treated waters nationa lly for TTHM? Click on "view report" to see the state and national levels of TTHM.

Quarter	State Report	National Report
JUL - SEP 1997	view report	view report
OCT - DEC 1997	view report	view report
JAN - MAR 1998	view report	view report
APR - JUN 1998	view report	view report
JUL - SEP 1998	view report	view report
OCT - DEC 1998	view report	view report

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