Rudolf G. WanneJL, M.P. 
Page 2 
OcXobeA 27, J976 
The. WSSC iA aZso conceded about the potenttaZty hoAm^uZ 
e^^ecti oi tn^ecttou6 mixiAooAgant&m to wa&tewateA peAAonnet (both 
WSSC and V.C. government) , to the treatment o£ the loaste, the 
diApohal ol the &oLid woite, to the 6a£e dU,po&at o^ the e^^ent 
into receiving mteJib and to the pubtie heatth. We Mould tike 
complete a&&urjonee that all in^ec£iou6 organl6m6 are effectively 
decontaminated prior to dupoiol to the sanitary heioer. Our concern 
hoi been reinforced by the ducuiiion in the guidelines concerning 
the effectiveness of decontaminants. It is our understanding, from 
revieu) cf the guidelines, that the effectiveness of a decontaminant 
is governed by many factors, such as 11) the concentration of active 
ingredients, (2) duration of contact, (3) ph, 14) temperature, 
1 5) humidity, and (6) presence of extrinsic organic matter. The 
guidelines indicate that any variance in the above factors from 
optimum conditions can cause the effectiveness of a decontaminant 
to range from minimal inactivation of microorganisms to a high 
degree of sterility. The guidelines also indicate that the effective- 
ness of a decontaminant depends upon whether or not the decontaminant 
actually contacts the microorganism. The dry areas under bubbles, 
spots of grease and rust or dirt on the object may protect micro- 
organisms from inactivation. Because the effectiveness of a decon- 
taminant depends upon so many factors the guidelines do not recommend 
complete reliance on liquid decontaminants , even when highly favorable 
conditions exist, when the end result must be sterility. If the 
effectiveness of inactivation of potentially harmful microorganisms 
can vary so greatly, what assurance do we have the NW's wastewater 
is not potentially harmful to WSSC’s concerns? 
The WSSC is also concerned about the chemicals being dis- 
charged into the sanitary sewer from NIH activities. Your guidelines 
indCcate that NIH uses several types of chemical decontaminants for 
cleaning laboratory equipment and facilities, for decontaminating 
spills from experiments, and for decontaminating liquid wastes con- 
taining recombinant VNA materials prior to disposal. All spent 
cleaning fluids are disposed of by flushing down the drain and a 
half-gallon of detergent- dexwntaminant solution is poured down some 
of the floor drains once a week to prevent backup of sewer gases. 
Chemical decontaminants mentioned in the guidelines include chlorine, 
iodophor, hypochlorite, peracetic acid, alcohol, ether, chloroform, 
formaldehyde, phenols, quaternary ammonium compounds, iodine, 
mercurials, chloride compounds, glutaraldehyde, and combinations of 
alcohol with iodine or formaldehyde. The WSSC is concerned that 
these chemicals may be discharged into the sanitary sewer in 
sufficient concentration to disrupt the biological or chemical 
wastewater treatment process. Your letter indicates that acids and 
bases are collected by the NIH Fire Department. After neutralization 
and dilution by this fire department, what are the kinds and con- 
centrations of chemicals discharged to the sanitary sewer? 
Appendix K — 113 
