Jump to main content.


EF/ ICR Logo Levels of Treated Water Total Trihalomethanes for WASHINGTON
JULY - SEPTEMBER 1998


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 i s 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.




CITY OF VANCOUVER

Water Type - GROUND WATER
(Tre ated Water)

Plant Name Plant ID Water Type Quarter Total Trihalomethanes Concentration (ppb)
LOWER ORCHARDS AQUIFER 692 Ground Water JUL 1998 - SEP 1998 0
UPPER ORCHARDS AQUIFER 693 Ground Water JUL 1998 - SEP 1998 1.1



City of Everett, Public Works Dept.

Water Type - SURFACE WATER
(Treated Water)

Plant Name Plant ID Water Type Quarter Total Trihalomethanes Concentration (ppb)
City of Everett Water Treatment Plant 686 Surface Water JUL 1998 - SEP 1998 33



City of Spokane

Water Type - GROUND WATER
(Treated Water)

Plant Name Plant ID Water Type Quarter Total Trihalomethanes Concentration (ppb)
Groundwater Treatment 690 Ground Water JUL 1998 - SEP 1998 0



Seattle Public Utilities

Water Type - SURFACE WATER
(Treated Water)

Plant Name Plant ID Water Type Quarter Total Trihalomethanes Concentration (ppb)
Landsburg Treatment Plant 688 Surface Water JUL 1998 - SEP 1998 25.8
Tolt Treatment Plant 689 Surface Water JUL 1998 - SEP 1998 57.4



Tacoma Public Utilities

Water Type - SURFACE WATER
(Treated Water)

Plant Name Plant ID Water Type Quarter Total Trihalomethanes Concentration (ppb)
Green River Headworks Purification Plant 691 Surface Water JUL 1998 - SEP 1998 45.7



Results for mixed water (ground water and surface water) and purchased water can be found under water system summary reports.


How does this state's treated water compare to treated waters nationally for Total Trihalomethanes?
View national data for the same month.


ICR Overview
Envirofacts Home Page


Local Navigation


Jump to main content.