Table 2.

Effects of categorical variables as percent increase or decrease of the mean HAN:THM ratio estimated for surface water.

Category	% Effect (2.5%, 97.5% CI)	Adjusted mean ratio	Sig.
Base-case: SW, FINISH, Summer, CL2-CL2		0.119	∗∗∗
Source water (FINISH, Summer, CL2-CL2)
GW	165 (122, 217)	0.315	∗∗∗
MIX	72.9 (31.4, 128)	0.205	∗∗∗
GI	52.7 (7.5, 117)	0.181	∗
PUR	24.1 (−30.6, 122)
Sampling location (SW, Summer, CL2-CL2)
DSE	−20.9 (−23.2, −18.6)	0.094	∗∗∗
AVG1	−26.4 (−28.5, −24.2)	0.087	∗∗∗
AVG2	−27.0 (−29.1, −24.9)	0.086	∗∗∗
MAX	−40.0 (−41.7, −38.2)	0.071	∗∗∗
Season (SW, FINISH, CL2-CL2)
Autumn	11.9 (8.7, 15.2)	0.133	∗∗∗
Winter	38.1 (33.6, 42.8)	0.164	∗∗∗
Spring	19.7 (15.7, 24.0)	0.142	∗∗∗
Disinfectant sequence (SW, FINISH, Summer)
CL2-CLM	1.0 (−11.8, 15.7)
Cl2-CLM-CLM	19.3 (61, 24.1)	0.141	∗∗∗
CLM	22.3 (1.1, 48.0)	0.145	∗
CLX-CL2	−28.5 (−45.0, −7.2)	0.085	∗
CLX-CLM	−11.8 (−27.3, 6.9)
CL2	−4.0 (−27.8, 27.7)
O3-CL2	11.9 (−8.6, 37.0)
O3-CLM	29.2 (3.7, 61.0)	0.153	∗

Table key: Sig.: significance to the ∗ 95%, ∗∗ 99%, or ∗∗∗ >99.9% confidence level. Disinfectant sequence abbreviations: chlorine (CL2), chloramines (CLM), chlorine dioxide (CLX), ozone (O3).

Table notes: Effect estimates in Table S5A were converted to percent effect by exponentiating, subtracting one, and multiplying by 100. To calculate the adjusted mean ratio for a particular category, add 100% to the percent effect and multiply by the conditional mean ratio (i.e., the intercept, the base-case, 0.119).