Wendy Steffensen and Jeff Hansen, LOTT’s Reclaimed Water Study: What we have learned so far about residual chemicals in our local waters

LOTT’s Reclaimed Water Study: What we have learned so far about residual

chemicals in our local waters

September 20, 2016South Sound Science Symposium; Shelton, WA

Wendy Steffensen, Environmental Project Manager, LOTTJeff Hansen, Project Manager, HDR

Presentation Outline

•LOTT and the Reclaimed Water Infiltration Study

•Notes on Interpreting Findings

•Task 1 Results (Water Quality Characterization)

•Task 2 Activities (Treatment Effectiveness

Evaluation)

LOTT Clean Water Alliance

Reclaimed Water Infiltration Study

Chemicals in the news Community concerns

Science Scope of Work

Public Involvement Plan

Information

Study ScopingReview of

Background Information

Review of Study Findings

Assessment of

Alternatives

Study Scoping Field WorkAnalysis/Modeling

Assessment of

Alternatives

Primary Study Question

What are the risks from

infiltrating reclaimed water into

groundwater because of

chemicals that may remain in the

water from products people use

every day, and what can be done

to reduce those risks?

Study Framework

1) Water Quality

Characterization

2) Treatment

Effectiveness

Evaluation

3) Risk

Assessment

4) Cost/Benefit

Analysis

• Wastewater

• Reclaimed Water

• Groundwater

• Surface Water

Water Quality Characterization

Study AreasReclaimed Water

Infiltration

No Reclaimed Water Infiltration

Henderson- No

reclaimed

water

infiltration

Hawks Prairie-

Reclaimed

water

infiltration

Study AreasReclaimed Water

Infiltration

No Reclaimed Water Infiltration

Henderson-

No reclaimed

water

infiltration

Hawks Prairie-

Reclaimed

water

infiltration

Regulated Chemicals and Parameters (282)

Unregulated/ Residual Chemicals (127)

• Medicines

• Personal Care Products / Foods

• Hormones

• Household Chemicals

Sampling

Scale / Concentration

Concentration Units Examples

1 part per million (ppm)

1 milligram/Liter (mg/L)

one drop in 10-gallon bucket

1 part per billion (ppb)

1microgram/Liter (µg/L)

one drop in 2 tankertrucks

1 part per trillion (ppt)

1 nanogram/Liter (ng/L)

one drop in 16 Olympic pools

Interpreting Findings: Analytical Challenges

•Low concentrations

•Variability

•Interference from other

organics

Interpreting Findings: Drawing Conclusions

•First step in study

•Soil Aquifer Treatment not characterized

•Detections of chemicals do not equal risk

1) Water Quality Characterization

2) Treatment Effectiveness

Evaluation

3) Risk Assessment

4) Cost/Benefit Analysis

Budd Inlet Reclaimed

Water Plant

Martin Way Reclaimed

Water Plant

Wastewater / Reclaimed Water

Characterization

Number of Residual Chemicals Detected

Martin Way

Reclaimed

Water Plant

Budd Inlet

Reclaimed

Water Plant

Wastewater 52 53

Reclaimed Water 34 29

Residual Chemicals Consistently Detected in Reclaimed Water

Good Removal >85% : n = 4

Example: Atenolol

LOTT: 36-230 ng/L

Other studies: 260-2440 ng/L

Residual Chemicals Consistently Detected in Reclaimed Water

Moderate Removal 33-85%: n = 7

Example: Carbamazepine

LOTT: 190-300 ng/L

Other studies: 97-1600 ng/L

Residual Chemicals Consistently Detected in Reclaimed Water

Poor to No Removal: n = 3

Example: Iohexal

LOTT: 240-14,000 ng/L

Other studies: 41-47,80 ng/L

Groundwater and Surface Water Quality

•Chemicals detected; Groundwater: 22, Surface: 15

•Chemicals with frequent detections at higher levels: Artificial sweeteners, flame retardants, select pharmaceuticals

•Potential sources: septic systems, stormwater runoff, and reclaimed water (where discharged)

Concentrations of Select Residual Chemicals

Concentrations of Select Residual Chemicals

Concentrations of Select Residual Chemicals

Concentrations of Select Residual Chemicals

Concentrations of Select Residual Chemicals

Concentrations of Select Residual Chemicals

Summary of Task 1 Findings

•Some residual chemicals are effectively removed,

while others are fairly recalcitrant.

•Some residual chemicals found in reclaimed water

are also found in the environment, including in

areas with no reclaimed water use.

•Findings in all media are similar to other studies.

Study Framework

1) Water Quality

Characterization

2) Treatment

Effectiveness

Evaluation

3) Risk

Assessment

4) Cost/Benefit

Analysis

What’s Next?

Risk Cost

Questions / Discussion

Wendy Steffensen, Environmental Project Manager, LOTT

[email protected]

Jeff Hansen, Project Manager, HDR

[email protected]

Concentrations of Nutrients

Concentrations of Nutrients

Concentrations of Nutrients

Surface Water Quality CharacterizationDeschutes River Woodland Creek

Mainstem Lower

Mainstem Upper

Beatty Springs

Eagle Creek

Fox Creek

Mainstem Lower

Mainstem Upper

Chambers Creek

Munn Lake

Percival Creek