republic-os/legislation/us/states/in/2023/sb-473.md

---
type: "Bill"
title: "Limits on discharges into the Ohio River."
description: "Provides that if a community water system that discharges wastewater into the Ohio River demonstrates to the satisfaction of the department of environmental management that the discharged wastewater does not increase the mass of mercury in the Ohio River by an amount greater than the mass of mercury in the water withdrawn from the Ohio River by the community water system: (1) the community water system's discharge into the Ohio River shall not be considered to cause, have a reasonable potential to cause, or contribute to an excursion above any applicable water quality standard governing mercury in the Ohio River; and (2) no water quality-based effluent limitations for mercury shall be required in a new or renewal NPDES permit issued to the community water system."
jurisdiction: "us/states/in"
legislature: "Indiana General Assembly"
session: "2023"
identifier: "SB 473"
citation: "Indiana SB 473 (2023)"
classification: ["bill"]
subjects: ["ENVIRONMENTAL MANAGEMENT", "DEPARTMENT AND AGENCIES", "RIVERS AND STREAMS", "WATER", "Pollution"]
status: "enacted"
primary_sponsors: ["James Tomes", "Rick Niemeyer", "Timothy O'Brien", "Vaneta Becker"]
version_count: 6
action_count: 24
vote_count: 1
first_action: "2023-01-19"
last_action: "2023-05-01"
source: "openstates"
source_identifier: "ocd-bill/3577b4a7-e020-4fad-9942-b9ca7e5f74c8"
source_url: "http://iga.in.gov/legislative/2023/bills/senate/473"
source_hash: "17d10800c06fddd5b8ce6d1e6f6369897c4b7a4690df92e5c38e9ff55454bd74"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-in"]
---

# Indiana SB 473 (2023) — Limits on discharges into the Ohio River.

Provides that if a community water system that discharges wastewater into the Ohio River demonstrates to the satisfaction of the department of environmental management that the discharged wastewater does not increase the mass of mercury in the Ohio River by an amount greater than the mass of mercury in the water withdrawn from the Ohio River by the community water system: (1) the community water system's discharge into the Ohio River shall not be considered to cause, have a reasonable potential to cause, or contribute to an excursion above any applicable water quality standard governing mercury in the Ohio River; and (2) no water quality-based effluent limitations for mercury shall be required in a new or renewal NPDES permit issued to the community water system.

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **Engrossed Senate Bill (S)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.03.ENGS)
2. **Engrossed Senate Bill (S)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.04.ENGS)
3. **Enrolled Senate Bill (S)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.06.ENRH)
4. **Introduced Senate Bill (S)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.01.INTR)
5. **Senate Bill (H)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.05.COMH)
6. **Senate Bill (S)** (committee substitute) — [source](http://in-proxy.openstates.org/2023/bills/SB0473/versions/SB0473.02.COMS)

## Votes

- SB 473 - O'Brien T - 3rd Reading — **95–2** (pass) · lower

## Sponsors

- James Tomes — primary (person)
- Rick Niemeyer — primary (person)
- Timothy O'Brien — primary (person)
- Vaneta Becker — primary (person)
- Matt Hostettler — cosponsor (person)
- Ryan Hatfield — cosponsor (person)
- Wendy McNamara — cosponsor (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2023-01-19** Authored by Senators Becker, Niemeyer and Tomes
- **2023-01-19** First reading: referred to Committee on Environmental Affairs `reading-1, referral-committee`
- **2023-02-14** Committee report: amend do pass, adopted `committee-passage`
- **2023-02-21** Amendment #1 (Becker) prevailed; voice vote `amendment-passage`
- **2023-02-21** Second reading: amended, ordered engrossed `reading-2`
- **2023-02-23** Pursuant to Senate Rule 35 (c); technical correction committee report adopted
- **2023-02-23** Third reading: passed; Roll Call 156: yeas 48, nays 0 `passage, reading-3, reading-3`
- **2023-02-23** House sponsor: Representative O'Brien
- **2023-02-23** Cosponsor: Representative Hatfield
- **2023-02-28** Referred to the House `referral`
- **2023-03-06** First reading: referred to Committee on Environmental Affairs `reading-1, referral-committee`
- **2023-03-30** Committee report: amend do pass, adopted `committee-passage`
- **2023-04-03** Second reading: ordered engrossed `reading-2`
- **2023-04-04** Representative McNamara added as cosponsor
- **2023-04-04** Representative Hostettler added as cosponsor
- **2023-04-04** Third reading: passed; Roll Call 362: yeas 95, nays 2 `passage, reading-3, reading-3`
- **2023-04-05** Returned to the Senate with amendments `receipt`
- **2023-04-05** Motion to concur filed `filing`
- **2023-04-10** Senate concurred in House amendments; Roll Call 360: yeas 49, nays 0
- **2023-04-13** Signed by the President Pro Tempore `passage`
- **2023-04-21** Signed by the Speaker `passage`
- **2023-04-26** Signed by the President of the Senate `passage`
- **2023-05-01** Public Law 116 `became-law`
- **2023-05-01** Signed by the Governor `executive-signature`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/3577b4a7-e020-4fad-9942-b9ca7e5f74c8`. Confidence: reported (aggregated from official Indiana legislature records).