Table 1 Water sample identifications (IDs) and description of treatment and sampling locations at Görvälnverket DWTP

Full-scale treatment process

 RW

Incoming raw water

Incoming raw water to Görvälnverket from lake Mälaren (Görväln basin) at 4 m or 22 m depth, after micro sieve, ambient pH

 SF

After coagulation and sand filtration

After coagulation/flocculation, sedimentation (or flotation) and sand filtration, pH ≈ 6.5–6.8

 BAC

After BAC filter

After the oldest full-scale filter (approx. 13 years, EBCT 5–6 min), Norit^® 830 W, pH ≈ 6.5–6.8

 UV

After UV

After UV disinfection (400 J/m²), pH ≈ 6.5–6.8

 DW

After NH₂Cl—finished drinking water

After the addition of monochloramine (0.2–0.38 mg excess chlorine/L) and lime, pH ≈ 8–8.3

 TAP-1

Tap water location #1

From a faucet at a location approximately 6 km in the distribution network from Görvälnverket

 TAP-2

Tap water location #2

From a faucet at a location approximately 50 km in the distribution network from Görvälnverket

Pilot-scale treatment process A

 O₃

After ozone treatment

After approximately 20 min of ozonation of sand filtrate water from full-scale, pH ≈ 6.5

 GAC-A

After GAC-A

Ozonated sand filtrate feed water, after treatment through a Norit^® 1240 W GAC filter column, EBCT 20 min, pH ≈ 6.5

Pilot-scale treatment process B

 GAC-B

After GAC-B

Sand filtrate feed water, no ozonation, after treatment through a Norit^® 1240 W GAC filter column, EBCT 20 min, pH ≈ 6.5–6.8