Pavel Hajda, Ph.D., P.E., Symbiont

1. 2011 IAWA Nutrient Study

2. Supplemental analysis

3. Other efforts

4. Conclusions

1. Identify technologies widely applicable to P and/or N removal upgrades

2. Assess the expected performance of those technologies

3. Express the above as effluent standard concepts

4. Support reasonable technology requirements in Springfield

Literature review focusing on established technologies

Critical assessment of the statistical basis of performance

Qualitative identification of sustainability issues (chemicals, sludge, and energy)

Only incidental coverage of costs

Biases:

where, when, for how long, in what plant context

potential gain or loss (information source/user)

Approach in this study:

reasonable target plant (not best in class)

central tendency of sustained operation

Configure activated sludge for biological phosphorus removal

Add metal salt to precipitate/adsorb dissolved phosphorus

Enhance solids removal beyond conventional secondary clarification

Nutrient Typical Raw Municipal

Wastewater

Level 0: Secondary Treatment

Level 1P: Basic Municipal Phosphorus Removal

Level 2P: Enhanced

Phosphorus Removal

Level 3P: Limit of

Technology Phosphorus

Removal Retrofit New

Construction

Total Phosphorus (TP), mg/L*

4 to 8 4 to 6 1.5 1 0.5 0.1

Relative Removal*

0% 20% 70% 80% 90% 98%

BPR (mostly) w/o chemical

Tertiary solids removal not required

Tertiary chemical not required

*Annual average/median.

How implemented:

combine biological nitrification with

▪ pre-anoxic zones (MLE), post-anoxic zones (Wuhrmann), simultaneous denitrification (macro or micro); and/or

▪ separate-stage (tertiary) denitrification activated sludge or attached-growth system

Nutrient Typical Raw Municipal

Wastewater

Level 0: Secondary Treatment

Level 1N: Basic Municipal Nitrogen Removal

Level 2N: Enhanced Nitrogen Removal

Level 3N: Limit of

Technology Nitrogen Removal Retrofit

New Construction

Total Nitrogen (TN), mg/L*

25 to 35 20 to 30 15 10 6 3

Total Inorg. N (TIN), mg/L*

12 8

Relative Removal (TN)*

0% 20% 50% 70% 80% 90%

Pre-anoxic zones sufficient

Supplemental carbon not required

Tertiary treatment not required

*Annual average/median.

Existing configuration imposes constraints:

plant type

tank size/configuration

footprint

hydraulics

solids processing and return streams

Upgrade choices have impacts:

reliability/controllability

costs, footprint

hydraulics/pumping, electricity use

chemical use/solids processing

staff needs (complexity)

sustainability

For phosphorus removal:

reduce chemical/solids impacts: BPR

avoid pumping: do without adding tertiary treatment

For nitrogen removal:

reduce chemical/solids impacts: rely on wastewater carbon (pre-anoxic zones)

avoid pumping: do without adding tertiary treatment

Very site-specific, but tend to increase with

number of nutrients to be removed

stringency of nutrient limits

existing plant/process constraints

for unit costs ($/gal): decreasing plant capacity

Making the same limit harder to meet:

shorter averaging periods (small “sample” n)

mean harder than median

absolute compliance harder than probabilistic

local conditions (influent, temperature…)

full inclusion of unknown refractory fractions

the rest of the permit (N/P, NH3, Al, Fe, Cl-, SO42-)

No standards for small plants

Annual medians for the rest:

TP at Level 1P

if nitrogen: TIN at Level 1N, with relative removal as an optional compliance pathway

“Report not strong enough to justify [Level 1P] standards”

Nutrient workgroup discussions on 11/28/11

1.0 mg/L monthly average TP widely met in IL

Follow-up call w/ IAWA on 12/8/11

Region 5 expected to insist on 0.5 mg/L TP

more detailed analysis of IL plants needed

▪ size, age, current technologies, upgrade needs expected to meet 1.0 and 0.5 mg/L

▪ cost information would be useful

IAWA’s objective: support Level 1P standard

Analysis of existing IL plant data to project the impact of 0.5 mg/L vs. 1.0 mg/L standard

capacity, plant type, TSS/TP limits and 12 months of performance (calendar 2011)

age data lacking, technology data limited

initial data sorts available for this presentation

Category Description Notes

1 activated sludge includes SBRs but not ditches and fixed-film hybrids

2 fixed film trickling filters, RBCs, and their combinations

3 fixed film hybrids TF/RBC combined w/ activated sludge or ditch

4 aerated lagoons rare above 1 MGD

5 oxidation ditches includes combinations with activated sludge

Other Descriptors Notes

nitrification (Y/N) determined from the presence of ammonia limits

tertiary filtration (Y/N) several types included in the database

IWEA Nutrients Committee:

Nutrient Survey results in “late spring or early summer 2012”

focused on available and planned nutrient removal technologies and costs

Technology Standards Stakeholder Subgroup

18 volunteers

venue likely to bring other efforts together

The rulemaking outcome likely to reflect

technology performance expectations

conclusions from statewide and plant-specific data

upgrade cost expectations

All of the above likely to be subjective

promote sensible outcomes by committed participation in the rulemaking process

Pavel Hajda Symbiont (414)291-8840 pavel.hajda@symbiontonline.com