289 patents currently held
14 more in force are now held by other companies
Held is read from USPTO's recorded assignments; a transfer never recorded there does not appear.
18 more records may belong here and await a decision; they are not counted.
The next term ends in Dec 2026. from the record
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
80
Ending by 2030
Dec 2026
Next term end
189
Patent families
When these terms end
Held patents by the year their term ends
notable patents
fee due within 90 days
all others
Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
Notable: the highest-ranked patents in this portfolio by citations and family size. Fee due within 90 days: a maintenance fee is due within 90 days of when this page was computed and not yet paid.
Notable patents
Ranked by citations and family size, against patents of the same kind granted the same year. How we rank
Notable
Ends May 2027 · High confidence
Also notable
Ends May 2028 · High confidence
Also notable
Ends Apr 2027 · High confidence
Water Treatment System and Method
US 8,377,279
Cited by 63 later US patents, top 10% of utility patents granted in 2013 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2027.
Membrane Cleaning with Pulsed Airlift Pump
US 8,287,743
Cited by 63 later US patents, top 10% of utility patents granted in 2012 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2028.
Water Treatment System and Method
US 7,604,725
Cited by 71 later US patents, top 10% of utility patents granted in 2009 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2027.
Fee deadlines
Maintenance fees fall due 3.5, 7.5 and 11.5 years after grant. A missed fee ends a patent at the end of the six month grace period that follows, not on the due date.
- 3 fees due Dec 13 to 20, 2026 · next Dec 13
- 3 fees due Jan 9 to 18, 2027 · next Jan 9
- 3 fees due Feb 1 to 27, 2027 · next Feb 1
- 1 fee due Mar 12, 2027The maintenance fee for Side Stream Treatment for Overflow (US 11,753,322) comes due Mar 12, 2027. Unpaid by Sep 13, 2027, it lapses early.
- 5 fees due Apr 3 to 30, 2027 · next Apr 3
- 2 fees due May 14 to 28, 2027 · next May 14
- 8 fees due Jun 3 to 24, 2027 · next Jun 3
- 4 fees due Jul 2 to 30, 2027 · next Jul 2
- 2 fees due Aug 9 to 18, 2027 · next Aug 9
- 3 fees due Sep 12, 2027
- 3 fees due Oct 7 to 21, 2027 · next Oct 7
- 1 fee due Nov 7, 2027The maintenance fee for Vanox Hot Water Cart Conditioning Method (US 11,975,294) comes due Nov 7, 2027. Unpaid by May 8, 2028, it lapses early.
Recent changes
- 7 of the patents on this record were granted since Aug 17, 2026
- 14 terms have ended since Aug 17, 2026
What they patent
The 5 largest of its 189 families, grouped by real patent family and labeled by the earliest filing in each. No technology classification is inferred from titles.
| System and Method for Enhancing an Activated Sludge Process | 9 in force | to Feb 2029 |
| Biofilter with Fuzzy Logic Control | 8 in force | to Jan 2036 |
| Method and System for Providing Ultrapure Water | 7 in force | to Jun 2029 |
| Membrane Cleaning with Pulsed Airlift Pump | 7 in force | to May 2029 |
| Hybrid Aerobic and Anaerobic Wastewater and Sludge Treatment Systems and Methods | 6 in force | to Oct 2030 |
Patents held now
Soonest term end first.
| Patent | Title | Status | Expires | Confidence |
|---|---|---|---|---|
| US 7,481,933 | Process to Improve the Efficiency of a Membrane Filter Activated Sludge System In force · High confidence | In force | High confidence | |
| US 7,867,417 | Membrane Post Treatment In force · High confidence | In force | High confidence | |
| US 7,563,363 | System for Treating Wastewater In force · High confidence | In force | High confidence | |
| US 7,604,725 | Water Treatment System and Method In force · High confidence | In force | High confidence | |
| US 7,988,891 | Monopersulfate Treatment of Membranes In force · High confidence | In force | High confidence | |
| US 8,377,279 | Water Treatment System and Method In force · High confidence | In force | High confidence | |
| US 10,550,020 | Ultraviolet Light Activated Oxidation Process for the Reduction of Organic Carbon in Semiconductor Process Water In force · High confidence | In force | High confidence | |
| US 12,103,874 | Ultraviolet Light Activated Oxidation Process for the Reduction of Organic Carbon in Semiconductor Process Water In force · High confidence | In force | High confidence | |
| US 9,586,842 | Low Scale Potential Water Treatment In force · Medium confidence | In force | Medium confidence | |
| US 8,894,834 | Water treatment system and method In force · Medium confidence | In force | Medium confidence |
Also on record, not counted in the 289: 14 patents in force now held by others · 166 patents ended · 68 applications pending · 72 applications abandoned. List them
Sources and methods
Compiled from USPTO application file histories, grants and recorded assignments, with the company's own names reviewed by hand. How this record was built
Portfolio grouped automatically from ownership conveyances to the names matched to this company, usually every name that begins with its own, so it counts patents an affiliate holds; each list row names the holder of record. Security interests are excluded and ambiguous records are not reviewed by hand.
Fee due within 90 days marks a patent with a maintenance fee due within 90 days of the date this page was computed and not yet recorded paid, so it can end earlier than the bar shows. A fee left unpaid ends the patent at the close of the six month grace period that follows its due date, not on the due date itself. It is not a prediction that the fee will be missed.
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.