# Presentation: 663165

## Surface Water Treatment Rule

**Bob Clement**
**Drinking Water Program**
**U.S. EPA Region 8**

## Surface Water Treatment RuleGround Water Reclassification

- _	__**PWS TYPE:**__	__	__**STATE DETERMINATION BY:**_
-      	CWS				6/29/94
-      	NCWS				6/29/99
-                                           40 CFR 142.16 (b)(2)(B) _______________________________________________________________________________
-     _DETERMINATION_			_ACTION_
-     Direct influence		     Meet avoidance criteria within                 	of surface water	     18 months or
- 			                Install filtration within 18     					     months   40 CFR 141.71

## Surface Water Treatment RuleGeneral Requirements

-  All surface water systems must 		          disinfect 		(40 CFR 141.70 (a))
-  Minimum 99.9 / 99.99% removal or 	inactivation of Giardia cysts / viruses                                                                                                                                                                                                (40 CFR 141.70(a)(1 & 2))
-  System operated by qualified personnel     (40 CFR 141.70(c))
-  Treatment specified by primary agency  (source water quality, site specific factors)   (40 CFR141.70(a))

## Surface Water Treatment RuleGeneral Requirements

-  **Applies to surface supplies and groundwater supplies under the influence of surface water**
**Regulates for Giardia, viruses, Legionella, ****	****heterotrophic bacteria, and turbidity**

## Cryptosporidium

**Cryptosporidium can survive for months in soil under cool, dark conditions and for up to a year in low turbidity water.**
**	****	****	**(Badenoch et al., 1990)
**Cryptosporidium is ubitquitous.  It is found even in the most pristine**** watersheds.**

## Cryptosporidium

- In almost all cases, wherever Giardia was present, Cryptosporidium was also present.  (LeChevallier et al., 1991a)
- We simply did not look for both at the same time in previous studies.  The highest level at a single site was 484 oocysts/L in Missouri.

## Cryptosporidium

- It would take up to 29,000 mg/l of CL2 to inactivate crypto.
- Traditional chlorination doesn’t work.  Physical removal by treatment is the only method of reduction for crypto.

## Cryptosporidium

- In an immuno-compromised individual, cryptosporidium can cause a debilitating condition and may be fatal.

## Surface Water Treatment Benefits

-  90,000 illnesses per year avoided
-  Waterborne disease outbreaks avoided
-  Improved consumer confidence, more aesthetic water
-  Removal of precursors to disinfection by-products
-  Removal of inorganic and synthetic 	organic chemicals

## Turbidity Monitoring RequirementsFiltered Systems

-  One measurement every 4 hours of 	operation by grab sample, or continuous monitoring
-  States may reduce monitoring to one grab sample / day in systems < 501 people regardless of treatment technology
-  Slow sand filtration and other technologies
-  State may reduce monitoring to one grab sample / day regardless of population size
- (40 CFR 141.74(c)(1))

## Turbidity Performance RequirementsFiltered Systems

-  All systems - never exceed 5 NTU (40 CFR 141.73)
-  Conventional treatment, direct filtration:  < 0.5 NTU 95% of measurements
- (State may allow up to < 1 NTU 95% of	measurements)  (40 CFR 141.73(a))
-  Diatomaceous earth filtration - < 1 NTU 95% of measurements (40 CFR 141.73 (c))

## Turbidity Performance RequirementsFiltered Systems

-  Slow sand and other filtration technologies
- 	 < 1 NTU 95% of measurements	(State may allow up to < 5 NTU 	95% of measurements but 		cannot exceed 5 NTU)
- 	(40 CFR 141.73 (b) and (d))

## Turbidity Standards

- Systems using a technology other than conventional, direct, slow sand or diatomaceous earth filtration are in compliance if: system demonstrates to the State that alternative filtration technology in combination with disinfection** ...  ****(40 CFR 141.73(d))**

## Turbidity Standards

- ... alternative filtration technology in combination with disinfection consistently achieves removal and/or inactivation of:
- 99.9% of Giardia lamblia cysts (filtration +  disinfection)
- 99.99% of viruses  (filtration + disinfection)
- 99% of Cryptosporidium  (filtration alone) (Interim Enhanced SWTR 12/16/98)

## Disinfection Requirements for Filtered Systems

-  Entry point to distribution system 40 CFR 141.74(c)(2)
-  Distribution system  40 CFR 141.74(c)(3)
-  Filtration and disinfection achieves at least 3/4 Log removal / inactivation (State determination) 141.70 (a)(1&2)

## Disinfection RequirementsEntry Point to Distribution System

- Residual entering distribution system
- 	cannot be < 0.2 mg/L for > 4 hours
- > 3300 people - continuous monitoring (grab sample allowed every 4 hours up to 5 days if monitoring equipment fails) 40 CFR 141.74(c)(2)
- 1-4 samples / day allowed for systems 	serving < 3301 people
- If residual is < 0.2 mg/L, must notify the State before end of next business day

## Disinfection RequirementsEntry Point to Distribution System

- 1-4 samples / day allowed for systems serving < 3301 people
- SIZE				# OF SAMPLES
- < 500					1
- 501-1000				2
- 1001-2500				3
- 2501-3,300				4
- If residual is < 0.2 mg/L, must notify the State before end of next business day
-       40 CFR 141.74(c)(2)

## Distribution System Disinfection Requirements

- Residual cannot be absent or HPC > 500ml in > 5% of samples/month for 2 mo.
- Monitoring locations / frequency (same as total coliform samples)
- For systems receiving groundwater and surface water, States may allow monitoring at surface water sites  40 CFR 141.74(c)(3)(i&ii)
- Above requirements do not apply if HPC monitoring not feasible and State determines adequacy of disinfection

## Recommended Removal and Disinfection Levels

- Assumed Log 			Recommended Log Removals				Disinfection
- _Treatment__	__	__Giardia  Viruses _    Giardia   Viruses_
- Conventional	   2.5	       2.0	       0.5	   2.0
- Direct Filtration	   2.0	       1.0	       1.0	   3.0
- Slow Sand 		   2.0	       2.0             1.0          2.0	Filtration

## Recommended Removal and Disinfection Levels

- Assumed Log 			Recommended Log Removals				Disinfection
- _Treatment__	__	__Giardia  Viruses _    Giardia   Viruses_
- Diatomaceous	   2.0         1.0             1.0	   3.0 Earth Filtration
- Bag/Cart 		   2.0	        0.0	       1.0	   4.0
- Membranes	   As determined by the State

## Disinfection Contact Times

- Contact time calculations will be easy when a spreadsheet is published in the American Water Works Association’s _OpFlow_ in the summer of 1999.