MOCKUP · LIMITS WORKSPACE click any pollutant row for its derivation ← all screens
In review Evaluation due · 122 days Allocate
Pollutants evaluated 17 six protection pathways each
Bound by biosolids 7 the most common controlling pathway
Most restrictive limit 0.034mg/L mercury · biosolids pathway
Provisional 2 silver · thallium — thin sampling data
Biosolids is the controlling pathway for 7 of 17 pollutants. Your Class A land application pathway is more restrictive than the receiving water for most metals. Moving to a ceiling-concentration pathway would relax cadmium, mercury, and arsenic — that is a policy decision, not a calculation. Change biosolids pathway →
Maximum allowable headworks loading by protection pathway
The binding criterion is highlighted on every row — click a row for its full derivation
lb/day
Pollutant Removal Pass through Interference & biosolids Result
Acute WQ Chronic WQ Human health Biosolids Act. sludge Digester MAHL MAIL Limit mg/L
AntimonySb 40% 9,382 4,114 20.0 20.0 17.9 2.148
Arsenic (total)As 50% 450.4 586.3 1.02 4.17 66.7 1.03 0.820 0.099
AluminumAl 85% 3,128 894.9 41.7 834.0 41.7 37.5 4.500
CadmiumCd 75% 2.05 2.59 0.650 417.0 4,587 0.650 0.480 0.058
Chromium (VI)Cr6 50% 19.1 32.1 41.7 4,587 19.1 17.2 2.058
Chromium (total)Cr 80% 1,745 513.0 23.4 417.0 1,668 23.4 19.4 2.329
CopperCu 85% 20.0 37.2 22.1 41.7 1,668 20.0 16.0 1.916
CyanideCN 60% 34.4 20.1 45.0 4.17 14,178 4.17 2.39 0.286
LeadPb 80% 43.7 4.20 4.69 4.17 14,178 4.17 2.12 0.254
MercuryHg 65% 4.42 0.801 0.327 0.330 0.280 0.034
MolybdenumMo 30% 3.12 41.7 417.0 3.12 2.48 0.297
NickelNi 45% 532.2 145.9 291.1 11.7 41.7 417.0 11.7 9.80 1.175
SeleniumSe 35% 19.2 11.9 184.8 3.57 10.4 542.1 3.57 3.18 0.381
SilverAg P 75% 3.10 10.4 3.10 2.63 0.315
ThalliumTl P 40% 5.67 5.67 5.10 0.612
TributyltinTBT 70% 0.959 0.370 12.5 0.370 0.330 0.040
ZincZn 80% 112.6 277.7 43.8 12.5 16,680 12.5 5.42 0.650
binding pathway — sets the MAHL P provisional — derived without sufficient site data no criterion for this pathway
Removal efficiency
2 pollutants fall back to reference regardless — silver and thallium lack the data.
Method
What binds, across the study
Biosolids 7
Act. sludge 4
Acute WQ 3
Human health 2
Chronic WQ 1
Digester 0

Digester inhibition never controls at this plant. Worth stating in the submittal — reviewers ask why a pathway was evaluated and then never governed.

Basis
Criteria library
v6 · 2026-01-15
Plant flow
5.00 MGD
Industrial flow
1.00 MGD
Acute / chronic DF
15 / 37
Human health DF
48
Hardness
25 mg/L
Biosolids pathway
Class A
Dry solids
6.25 ton/d